Remove unused logout function from event handler

.github/workflows/docs-ack.yml

@@ -16,29 +16,19 @@ jobs:
     steps:
       - name: Read PR body
         id: body
-        shell: bash
         run: |
-          set -euo pipefail
-          BODY_B64=$(jq -r '.pull_request.body // "" | @base64' "$GITHUB_EVENT_PATH")
-          {
-            echo "body_b64=$BODY_B64"
-          } >> "$GITHUB_OUTPUT"
+          BODY=$(jq -r '.pull_request.body // ""' "$GITHUB_EVENT_PATH")
+          echo "body<<EOF" >> $GITHUB_OUTPUT
+          echo "$BODY" >> $GITHUB_OUTPUT
+          echo "EOF" >> $GITHUB_OUTPUT
 
       - name: Validate checkbox selection
         id: validate
-        shell: bash
-        env:
-          BODY_B64: ${{ steps.body.outputs.body_b64 }}
         run: |
-          set -euo pipefail
-          if ! body="$(printf '%s' "$BODY_B64" | base64 -d)"; then
-            echo "::error::Failed to decode PR body from base64. Data may be corrupted or missing."
-            exit 1
-          fi
-
-          added_checked=$(printf '%s' "$body" | grep -Ei '^[[:space:]]*-\s*\[x\]\s*I added/updated documentation' | wc -l | tr -d '[:space:]' || true)
-          noneed_checked=$(printf '%s' "$body" | grep -Ei '^[[:space:]]*-\s*\[x\]\s*Documentation is \*\*not needed\*\*' | wc -l | tr -d '[:space:]' || true)
+          body='${{ steps.body.outputs.body }}'
 
+          added_checked=$(printf "%s" "$body" | grep -E '^- \[x\] I added/updated documentation' -i | wc -l | tr -d ' ')
+          noneed_checked=$(printf "%s" "$body" | grep -E '^- \[x\] Documentation is \*\*not needed\*\*' -i | wc -l | tr -d ' ')
 
           if [ "$added_checked" -eq 1 ] && [ "$noneed_checked" -eq 1 ]; then
             echo "::error::Choose exactly one: either 'docs added' OR 'not needed'."
@@ -51,35 +41,30 @@ jobs:
           fi
 
           if [ "$added_checked" -eq 1 ]; then
-            echo "mode=added" >> "$GITHUB_OUTPUT"
+            echo "mode=added" >> $GITHUB_OUTPUT
           else
-            echo "mode=noneed" >> "$GITHUB_OUTPUT"
+            echo "mode=noneed" >> $GITHUB_OUTPUT
           fi
 
       - name: Extract docs PR URL (when 'docs added')
         if: steps.validate.outputs.mode == 'added'
         id: extract
-        shell: bash
-        env:
-          BODY_B64: ${{ steps.body.outputs.body_b64 }}
         run: |
-          set -euo pipefail
-          body="$(printf '%s' "$BODY_B64" | base64 -d)"
+          body='${{ steps.body.outputs.body }}'
 
           # Strictly require HTTPS and that it's a PR in netbirdio/docs
-          # e.g., https://github.com/netbirdio/docs/pull/1234
-          url="$(printf '%s' "$body" | grep -Eo 'https://github\.com/netbirdio/docs/pull/[0-9]+' | head -n1 || true)"
+          # Examples accepted:
+          #   https://github.com/netbirdio/docs/pull/1234
+          url=$(printf "%s" "$body" | grep -Eo 'https://github\.com/netbirdio/docs/pull/[0-9]+' | head -n1 || true)
 
-          if [ -z "${url:-}" ]; then
+          if [ -z "$url" ]; then
             echo "::error::You checked 'docs added' but didn't include a valid HTTPS PR link to netbirdio/docs (e.g., https://github.com/netbirdio/docs/pull/1234)."
             exit 1
           fi
 
-          pr_number="$(printf '%s' "$url" | sed -E 's#.*/pull/([0-9]+)$#\1#')"
-          {
-            echo "url=$url"
-            echo "pr_number=$pr_number"
-          } >> "$GITHUB_OUTPUT"
+          pr_number=$(echo "$url" | sed -E 's#.*/pull/([0-9]+)$#\1#')
+          echo "url=$url" >> $GITHUB_OUTPUT
+          echo "pr_number=$pr_number" >> $GITHUB_OUTPUT
 
       - name: Verify docs PR exists (and is open or merged)
         if: steps.validate.outputs.mode == 'added'

.github/workflows/golang-test-freebsd.yml

@@ -25,7 +25,8 @@ jobs:
           release: "14.2"
           prepare: |
             pkg install -y curl pkgconf xorg
-            GO_TARBALL="go1.23.12.freebsd-amd64.tar.gz"
+            LATEST_VERSION=$(curl -s https://go.dev/VERSION?m=text|head -n 1)
+            GO_TARBALL="$LATEST_VERSION.freebsd-amd64.tar.gz"
             GO_URL="https://go.dev/dl/$GO_TARBALL"
             curl -vLO "$GO_URL"
             tar -C /usr/local -vxzf "$GO_TARBALL"            

.github/workflows/golang-test-linux.yml

@@ -217,7 +217,7 @@ jobs:
           - arch: "386"
             raceFlag: ""
           - arch: "amd64"
-            raceFlag: "-race"
+            raceFlag: ""
     runs-on: ubuntu-22.04
     steps:
       - name: Install Go
@@ -382,32 +382,6 @@ jobs:
         store: [ 'sqlite', 'postgres' ]
     runs-on: ubuntu-22.04
     steps:
-      - name: Create Docker network
-        run: docker network create promnet
-
-      - name: Start Prometheus Pushgateway
-        run: docker run -d --name pushgateway --network promnet -p 9091:9091 prom/pushgateway
-
-      - name: Start Prometheus (for Pushgateway forwarding)
-        run: |
-          echo '
-          global:
-            scrape_interval: 15s
-          scrape_configs:
-            - job_name: "pushgateway"
-              static_configs:
-                - targets: ["pushgateway:9091"]
-          remote_write:
-            - url: ${{ secrets.GRAFANA_URL }}
-              basic_auth:
-                username: ${{ secrets.GRAFANA_USER }}
-                password: ${{ secrets.GRAFANA_API_KEY }}
-          ' > prometheus.yml
-
-          docker run -d --name prometheus --network promnet \
-            -v $PWD/prometheus.yml:/etc/prometheus/prometheus.yml \
-            -p 9090:9090 \
-            prom/prometheus
       - name: Install Go
         uses: actions/setup-go@v5
         with:
@@ -454,10 +428,9 @@ jobs:
           CGO_ENABLED=1 GOARCH=${{ matrix.arch }} \
           NETBIRD_STORE_ENGINE=${{ matrix.store }} \
           CI=true \
-          GIT_BRANCH=${{ github.ref_name }} \
           go test -tags devcert -run=^$ -bench=. \
-          -exec 'sudo --preserve-env=CI,NETBIRD_STORE_ENGINE,GIT_BRANCH,GITHUB_RUN_ID' \
-          -timeout 20m ./management/... ./shared/management/... $(go list ./management/... ./shared/management/... | grep -v -e /management/server/http)
+          -exec 'sudo --preserve-env=CI,NETBIRD_STORE_ENGINE' \
+          -timeout 20m ./management/... ./shared/management/...
 
   api_benchmark:
     name: "Management / Benchmark (API)"
@@ -548,7 +521,7 @@ jobs:
             -run=^$ \
             -bench=. \
             -exec 'sudo --preserve-env=CI,NETBIRD_STORE_ENGINE,GIT_BRANCH,GITHUB_RUN_ID' \
-            -timeout 20m ./management/server/http/...
+            -timeout 20m ./management/... ./shared/management/...
 
   api_integration_test:
     name: "Management / Integration"
@@ -598,4 +571,4 @@ jobs:
           CI=true \
           go test -tags=integration \
           -exec 'sudo --preserve-env=CI,NETBIRD_STORE_ENGINE' \
-          -timeout 20m ./management/server/http/...
+          -timeout 20m ./management/... ./shared/management/...

.github/workflows/golang-test-windows.yml

@@ -63,7 +63,7 @@ jobs:
       - run: PsExec64 -s -w ${{ github.workspace }} C:\hostedtoolcache\windows\go\${{ steps.go.outputs.go-version }}\x64\bin\go.exe env -w GOMODCACHE=${{ env.cache }}
       - run: PsExec64 -s -w ${{ github.workspace }} C:\hostedtoolcache\windows\go\${{ steps.go.outputs.go-version }}\x64\bin\go.exe env -w GOCACHE=${{ env.modcache }}
       - run: PsExec64 -s -w ${{ github.workspace }} C:\hostedtoolcache\windows\go\${{ steps.go.outputs.go-version }}\x64\bin\go.exe mod tidy
-      - run: echo "files=$(go list ./... | ForEach-Object { $_ } | Where-Object { $_ -notmatch '/management' } | Where-Object { $_ -notmatch '/relay' } | Where-Object { $_ -notmatch '/signal' })" >> $env:GITHUB_ENV
+      - run: echo "files=$(go list ./... | ForEach-Object { $_ } | Where-Object { $_ -notmatch '/management' })" >> $env:GITHUB_ENV
 
       - name: test
         run: PsExec64 -s -w ${{ github.workspace }} cmd.exe /c "C:\hostedtoolcache\windows\go\${{ steps.go.outputs.go-version }}\x64\bin\go.exe test -tags=devcert -timeout 10m -p 1 ${{ env.files }} > test-out.txt 2>&1"

.github/workflows/golangci-lint.yml

@@ -19,7 +19,7 @@ jobs:
       - name: codespell
         uses: codespell-project/actions-codespell@v2
         with:
-          ignore_words_list: erro,clienta,hastable,iif,groupd,testin,groupe,cros
+          ignore_words_list: erro,clienta,hastable,iif,groupd,testin,groupe
           skip: go.mod,go.sum
   golangci:
     strategy:

.github/workflows/release.yml

@@ -9,7 +9,7 @@ on:
   pull_request:
 
 env:
-  SIGN_PIPE_VER: "v0.0.23"
+  SIGN_PIPE_VER: "v0.0.22"
   GORELEASER_VER: "v2.3.2"
   PRODUCT_NAME: "NetBird"
   COPYRIGHT: "NetBird GmbH"

.github/workflows/test-infrastructure-files.yml

@@ -83,15 +83,6 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v4
 
-      - name: Setup MySQL privileges
-        if: matrix.store == 'mysql'
-        run: |
-          sleep 10
-          mysql -h 127.0.0.1 -u root -pmysqlroot -e "
-            GRANT SYSTEM_VARIABLES_ADMIN ON *.* TO 'netbird'@'%';
-            FLUSH PRIVILEGES;
-          "
-
       - name: cp setup.env
         run: cp infrastructure_files/tests/setup.env infrastructure_files/
 

.github/workflows/wasm-build-validation.yml

@@ -1,67 +0,0 @@
-name: Wasm
-
-on:
-  push:
-    branches:
-      - main
-  pull_request:
-
-concurrency:
-  group: ${{ github.workflow }}-${{ github.ref }}-${{ github.head_ref || github.actor_id }}
-  cancel-in-progress: true
-
-jobs:
-  js_lint:
-    name: "JS / Lint"
-    runs-on: ubuntu-latest
-    steps:
-      - name: Checkout repository
-        uses: actions/checkout@v4
-      - name: Install Go
-        uses: actions/setup-go@v5
-        with:
-          go-version: "1.23.x"
-      - name: Install dependencies
-        run: sudo apt update && sudo apt install -y -q libgtk-3-dev libayatana-appindicator3-dev libgl1-mesa-dev xorg-dev libpcap-dev
-      - name: Install golangci-lint
-        uses: golangci/golangci-lint-action@d6238b002a20823d52840fda27e2d4891c5952dc
-        with:
-          version: latest
-          install-mode: binary
-          skip-cache: true
-          skip-pkg-cache: true
-          skip-build-cache: true
-      - name: Run golangci-lint for WASM
-        run: |
-          GOOS=js GOARCH=wasm golangci-lint run --timeout=12m --out-format colored-line-number ./client/...
-        continue-on-error: true
-
-  js_build:
-    name: "JS / Build"
-    runs-on: ubuntu-latest
-    steps:
-      - name: Checkout repository
-        uses: actions/checkout@v4
-      - name: Install Go
-        uses: actions/setup-go@v5
-        with:
-          go-version: "1.23.x"
-      - name: Build Wasm client
-        run: GOOS=js GOARCH=wasm go build -o netbird.wasm ./client/wasm/cmd
-        env:
-          CGO_ENABLED: 0
-      - name: Check Wasm build size
-        run: |
-          echo "Wasm build size:"
-          ls -lh netbird.wasm
-
-          SIZE=$(stat -c%s netbird.wasm)
-          SIZE_MB=$((SIZE / 1024 / 1024))
-
-          echo "Size: ${SIZE} bytes (${SIZE_MB} MB)"
-
-          if [ ${SIZE} -gt 52428800 ]; then
-            echo "Wasm binary size (${SIZE_MB}MB) exceeds 50MB limit!"
-            exit 1
-          fi
-

.goreleaser.yaml

@@ -2,18 +2,6 @@ version: 2
 
 project_name: netbird
 builds:
-  - id: netbird-wasm
-    dir: client/wasm/cmd
-    binary: netbird
-    env: [GOOS=js, GOARCH=wasm, CGO_ENABLED=0]
-    goos:
-      - js
-    goarch:
-      - wasm
-    ldflags:
-      - -s -w -X github.com/netbirdio/netbird/version.version={{.Version}} -X main.commit={{.Commit}} -X main.date={{.CommitDate}} -X main.builtBy=goreleaser
-    mod_timestamp: "{{ .CommitTimestamp }}"
-
   - id: netbird
     dir: client
     binary: netbird
@@ -127,11 +115,6 @@ archives:
   - builds:
       - netbird
       - netbird-static
-  - id: netbird-wasm
-    builds:
-      - netbird-wasm
-    name_template: "{{ .ProjectName }}_{{ .Version }}"
-    format: binary
 
 nfpms:
   - maintainer: Netbird <dev@netbird.io>

README.md

@@ -1,4 +1,3 @@
-
 <div align="center">
 <br/>
   <br/>
@@ -53,7 +52,7 @@
 
 ### Open Source Network Security in a Single Platform
 
-https://github.com/user-attachments/assets/10cec749-bb56-4ab3-97af-4e38850108d2
+<img width="1188" alt="centralized-network-management 1" src="https://github.com/user-attachments/assets/c28cc8e4-15d2-4d2f-bb97-a6433db39d56" />
 
 ### NetBird on Lawrence Systems (Video)
 [![Watch the video](https://img.youtube.com/vi/Kwrff6h0rEw/0.jpg)](https://www.youtube.com/watch?v=Kwrff6h0rEw)

client/Dockerfile

@@ -4,7 +4,7 @@
 #   sudo podman build -t localhost/netbird:latest -f client/Dockerfile --ignorefile .dockerignore-client .
 #   sudo podman run --rm -it --cap-add={BPF,NET_ADMIN,NET_RAW} localhost/netbird:latest
 
-FROM alpine:3.22.2
+FROM alpine:3.22.0
 # iproute2: busybox doesn't display ip rules properly
 RUN apk add --no-cache \
     bash \
@@ -18,7 +18,7 @@ ENV \
     NB_LOG_FILE="console,/var/log/netbird/client.log" \
     NB_DAEMON_ADDR="unix:///var/run/netbird.sock" \
     NB_ENTRYPOINT_SERVICE_TIMEOUT="5" \
-    NB_ENTRYPOINT_LOGIN_TIMEOUT="5"
+    NB_ENTRYPOINT_LOGIN_TIMEOUT="1"
 
 ENTRYPOINT [ "/usr/local/bin/netbird-entrypoint.sh" ]
 

client/android/client.go

@@ -4,7 +4,6 @@ package android
 
 import (
 	"context"
-	"os"
 	"slices"
 	"sync"
 
@@ -19,7 +18,7 @@ import (
 	"github.com/netbirdio/netbird/client/internal/stdnet"
 	"github.com/netbirdio/netbird/client/system"
 	"github.com/netbirdio/netbird/formatter"
-	"github.com/netbirdio/netbird/client/net"
+	"github.com/netbirdio/netbird/util/net"
 )
 
 // ConnectionListener export internal Listener for mobile
@@ -84,8 +83,7 @@ func NewClient(cfgFile string, androidSDKVersion int, deviceName string, uiVersi
 }
 
 // Run start the internal client. It is a blocker function
-func (c *Client) Run(urlOpener URLOpener, dns *DNSList, dnsReadyListener DnsReadyListener, envList *EnvList) error {
-	exportEnvList(envList)
+func (c *Client) Run(urlOpener URLOpener, dns *DNSList, dnsReadyListener DnsReadyListener) error {
 	cfg, err := profilemanager.UpdateOrCreateConfig(profilemanager.ConfigInput{
 		ConfigPath: c.cfgFile,
 	})
@@ -120,8 +118,7 @@ func (c *Client) Run(urlOpener URLOpener, dns *DNSList, dnsReadyListener DnsRead
 
 // RunWithoutLogin we apply this type of run function when the backed has been started without UI (i.e. after reboot).
 // In this case make no sense handle registration steps.
-func (c *Client) RunWithoutLogin(dns *DNSList, dnsReadyListener DnsReadyListener, envList *EnvList) error {
-	exportEnvList(envList)
+func (c *Client) RunWithoutLogin(dns *DNSList, dnsReadyListener DnsReadyListener) error {
 	cfg, err := profilemanager.UpdateOrCreateConfig(profilemanager.ConfigInput{
 		ConfigPath: c.cfgFile,
 	})
@@ -252,14 +249,3 @@ func (c *Client) SetConnectionListener(listener ConnectionListener) {
 func (c *Client) RemoveConnectionListener() {
 	c.recorder.RemoveConnectionListener()
 }
-
-func exportEnvList(list *EnvList) {
-	if list == nil {
-		return
-	}
-	for k, v := range list.AllItems() {
-		if err := os.Setenv(k, v); err != nil {
-			log.Errorf("could not set env variable %s: %v", k, err)
-		}
-	}
-}

client/android/env_list.go

@@ -1,32 +0,0 @@
-package android
-
-import "github.com/netbirdio/netbird/client/internal/peer"
-
-var (
-	// EnvKeyNBForceRelay Exported for Android java client
-	EnvKeyNBForceRelay = peer.EnvKeyNBForceRelay
-)
-
-// EnvList wraps a Go map for export to Java
-type EnvList struct {
-	data map[string]string
-}
-
-// NewEnvList creates a new EnvList
-func NewEnvList() *EnvList {
-	return &EnvList{data: make(map[string]string)}
-}
-
-// Put adds a key-value pair
-func (el *EnvList) Put(key, value string) {
-	el.data[key] = value
-}
-
-// Get retrieves a value by key
-func (el *EnvList) Get(key string) string {
-	return el.data[key]
-}
-
-func (el *EnvList) AllItems() map[string]string {
-	return el.data
-}

client/android/login.go

@@ -33,7 +33,6 @@ type ErrListener interface {
 // the backend want to show an url for the user
 type URLOpener interface {
 	Open(string)
-	OnLoginSuccess()
 }
 
 // Auth can register or login new client
@@ -182,11 +181,6 @@ func (a *Auth) login(urlOpener URLOpener) error {
 
 	err = a.withBackOff(a.ctx, func() error {
 		err := internal.Login(a.ctx, a.config, "", jwtToken)
-
-		if err == nil {
-			go urlOpener.OnLoginSuccess()
-		}
-
 		if s, ok := gstatus.FromError(err); ok && (s.Code() == codes.InvalidArgument || s.Code() == codes.PermissionDenied) {
 			return nil
 		}
@@ -200,7 +194,7 @@ func (a *Auth) login(urlOpener URLOpener) error {
 }
 
 func (a *Auth) foregroundGetTokenInfo(urlOpener URLOpener) (*auth.TokenInfo, error) {
-	oAuthFlow, err := auth.NewOAuthFlow(a.ctx, a.config, false, "")
+	oAuthFlow, err := auth.NewOAuthFlow(a.ctx, a.config, false)
 	if err != nil {
 		return nil, err
 	}

client/cmd/debug.go

@@ -33,7 +33,7 @@ var (
 var debugCmd = &cobra.Command{
 	Use:   "debug",
 	Short: "Debugging commands",
-	Long:  "Commands for debugging and logging within the NetBird daemon.",
+	Long:  "Provides commands for debugging and logging control within the NetBird daemon.",
 }
 
 var debugBundleCmd = &cobra.Command{
@@ -168,7 +168,7 @@ func runForDuration(cmd *cobra.Command, args []string) error {
 
 	client := proto.NewDaemonServiceClient(conn)
 
-	stat, err := client.Status(cmd.Context(), &proto.StatusRequest{ShouldRunProbes: true})
+	stat, err := client.Status(cmd.Context(), &proto.StatusRequest{})
 	if err != nil {
 		return fmt.Errorf("failed to get status: %v", status.Convert(err).Message())
 	}
@@ -303,18 +303,12 @@ func setSyncResponsePersistence(cmd *cobra.Command, args []string) error {
 
 func getStatusOutput(cmd *cobra.Command, anon bool) string {
 	var statusOutputString string
-	statusResp, err := getStatus(cmd.Context(), true)
+	statusResp, err := getStatus(cmd.Context())
 	if err != nil {
 		cmd.PrintErrf("Failed to get status: %v\n", err)
 	} else {
-		pm := profilemanager.NewProfileManager()
-		var profName string
-		if activeProf, err := pm.GetActiveProfile(); err == nil {
-			profName = activeProf.Name
-		}
-
 		statusOutputString = nbstatus.ParseToFullDetailSummary(
-			nbstatus.ConvertToStatusOutputOverview(statusResp, anon, "", nil, nil, nil, "", profName),
+			nbstatus.ConvertToStatusOutputOverview(statusResp, anon, "", nil, nil, nil, "", ""),
 		)
 	}
 	return statusOutputString

client/cmd/debug_js.go

@@ -1,8 +0,0 @@
-package cmd
-
-import "context"
-
-// SetupDebugHandler is a no-op for WASM
-func SetupDebugHandler(context.Context, interface{}, interface{}, interface{}, string) {
-	// Debug handler not needed for WASM
-}

client/cmd/down.go

@@ -14,8 +14,7 @@ import (
 
 var downCmd = &cobra.Command{
 	Use:   "down",
-	Short: "Disconnect from the NetBird network",
-	Long:  "Disconnect the NetBird client from the network and management service. This will terminate all active connections with the remote peers.",
+	Short: "down netbird connections",
 	RunE: func(cmd *cobra.Command, args []string) error {
 		SetFlagsFromEnvVars(rootCmd)
 
@@ -27,7 +26,7 @@ var downCmd = &cobra.Command{
 			return err
 		}
 
-		ctx, cancel := context.WithTimeout(context.Background(), time.Second*20)
+		ctx, cancel := context.WithTimeout(context.Background(), time.Second*7)
 		defer cancel()
 
 		conn, err := DialClientGRPCServer(ctx, daemonAddr)

client/cmd/login.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"fmt"
 	"os"
-	"os/exec"
 	"os/user"
 	"runtime"
 	"strings"
@@ -32,8 +31,7 @@ func init() {
 
 var loginCmd = &cobra.Command{
 	Use:   "login",
-	Short: "Log in to the NetBird network",
-	Long:  "Log in to the NetBird network using a setup key or SSO",
+	Short: "login to the NetBird Management Service (first run)",
 	RunE: func(cmd *cobra.Command, args []string) error {
 		if err := setEnvAndFlags(cmd); err != nil {
 			return fmt.Errorf("set env and flags: %v", err)
@@ -106,13 +104,6 @@ func doDaemonLogin(ctx context.Context, cmd *cobra.Command, providedSetupKey str
 		Username:            &username,
 	}
 
-	profileState, err := pm.GetProfileState(activeProf.Name)
-	if err != nil {
-		log.Debugf("failed to get profile state for login hint: %v", err)
-	} else if profileState.Email != "" {
-		loginRequest.Hint = &profileState.Email
-	}
-
 	if rootCmd.PersistentFlags().Changed(preSharedKeyFlag) {
 		loginRequest.OptionalPreSharedKey = &preSharedKey
 	}
@@ -235,7 +226,7 @@ func doForegroundLogin(ctx context.Context, cmd *cobra.Command, setupKey string,
 	}
 
 	// update host's static platform and system information
-	system.UpdateStaticInfoAsync()
+	system.UpdateStaticInfo()
 
 	configFilePath, err := activeProf.FilePath()
 	if err != nil {
@@ -248,7 +239,7 @@ func doForegroundLogin(ctx context.Context, cmd *cobra.Command, setupKey string,
 		return fmt.Errorf("read config file %s: %v", configFilePath, err)
 	}
 
-	err = foregroundLogin(ctx, cmd, config, setupKey, activeProf.Name)
+	err = foregroundLogin(ctx, cmd, config, setupKey)
 	if err != nil {
 		return fmt.Errorf("foreground login failed: %v", err)
 	}
@@ -276,7 +267,7 @@ func handleSSOLogin(ctx context.Context, cmd *cobra.Command, loginResp *proto.Lo
 	return nil
 }
 
-func foregroundLogin(ctx context.Context, cmd *cobra.Command, config *profilemanager.Config, setupKey, profileName string) error {
+func foregroundLogin(ctx context.Context, cmd *cobra.Command, config *profilemanager.Config, setupKey string) error {
 	needsLogin := false
 
 	err := WithBackOff(func() error {
@@ -293,7 +284,7 @@ func foregroundLogin(ctx context.Context, cmd *cobra.Command, config *profileman
 
 	jwtToken := ""
 	if setupKey == "" && needsLogin {
-		tokenInfo, err := foregroundGetTokenInfo(ctx, cmd, config, profileName)
+		tokenInfo, err := foregroundGetTokenInfo(ctx, cmd, config)
 		if err != nil {
 			return fmt.Errorf("interactive sso login failed: %v", err)
 		}
@@ -322,17 +313,8 @@ func foregroundLogin(ctx context.Context, cmd *cobra.Command, config *profileman
 	return nil
 }
 
-func foregroundGetTokenInfo(ctx context.Context, cmd *cobra.Command, config *profilemanager.Config, profileName string) (*auth.TokenInfo, error) {
-	hint := ""
-	pm := profilemanager.NewProfileManager()
-	profileState, err := pm.GetProfileState(profileName)
-	if err != nil {
-		log.Debugf("failed to get profile state for login hint: %v", err)
-	} else if profileState.Email != "" {
-		hint = profileState.Email
-	}
-
-	oAuthFlow, err := auth.NewOAuthFlow(ctx, config, isUnixRunningDesktop(), hint)
+func foregroundGetTokenInfo(ctx context.Context, cmd *cobra.Command, config *profilemanager.Config) (*auth.TokenInfo, error) {
+	oAuthFlow, err := auth.NewOAuthFlow(ctx, config, isUnixRunningDesktop())
 	if err != nil {
 		return nil, err
 	}
@@ -373,21 +355,13 @@ func openURL(cmd *cobra.Command, verificationURIComplete, userCode string, noBro
 	cmd.Println("")
 
 	if !noBrowser {
-		if err := openBrowser(verificationURIComplete); err != nil {
+		if err := open.Run(verificationURIComplete); err != nil {
 			cmd.Println("\nAlternatively, you may want to use a setup key, see:\n\n" +
 				"https://docs.netbird.io/how-to/register-machines-using-setup-keys")
 		}
 	}
 }
 
-// openBrowser opens the URL in a browser, respecting the BROWSER environment variable.
-func openBrowser(url string) error {
-	if browser := os.Getenv("BROWSER"); browser != "" {
-		return exec.Command(browser, url).Start()
-	}
-	return open.Run(url)
-}
-
 // isUnixRunningDesktop checks if a Linux OS is running desktop environment
 func isUnixRunningDesktop() bool {
 	if runtime.GOOS != "linux" && runtime.GOOS != "freebsd" {

client/cmd/logout.go

@@ -14,8 +14,7 @@ import (
 var logoutCmd = &cobra.Command{
 	Use:     "deregister",
 	Aliases: []string{"logout"},
-	Short:   "Deregister from the NetBird management service and delete this peer",
-	Long:    "This command will deregister the current peer from the NetBird management service and all associated configuration. Use with caution as this will remove the peer from the network.",
+	Short:   "deregister from the NetBird Management Service and delete peer",
 	RunE: func(cmd *cobra.Command, args []string) error {
 		SetFlagsFromEnvVars(rootCmd)
 

client/cmd/networks.go

@@ -15,7 +15,7 @@ var appendFlag bool
 var networksCMD = &cobra.Command{
 	Use:     "networks",
 	Aliases: []string{"routes"},
-	Short:   "Manage connections to NetBird Networks and Resources",
+	Short:   "Manage networks",
 	Long:    `Commands to list, select, or deselect networks. Replaces the "routes" command.`,
 }
 

client/cmd/profile.go

@@ -16,13 +16,13 @@ import (
 
 var profileCmd = &cobra.Command{
 	Use:   "profile",
-	Short: "Manage NetBird client profiles",
-	Long:  `Commands to list, add, remove, and switch profiles. Profiles allow you to maintain different accounts in one client app.`,
+	Short: "manage NetBird profiles",
+	Long:  `Manage NetBird profiles, allowing you to list, switch, and remove profiles.`,
 }
 
 var profileListCmd = &cobra.Command{
 	Use:     "list",
-	Short:   "List all profiles",
+	Short:   "list all profiles",
 	Long:    `List all available profiles in the NetBird client.`,
 	Aliases: []string{"ls"},
 	RunE:    listProfilesFunc,
@@ -30,7 +30,7 @@ var profileListCmd = &cobra.Command{
 
 var profileAddCmd = &cobra.Command{
 	Use:   "add <profile_name>",
-	Short: "Add a new profile",
+	Short: "add a new profile",
 	Long:  `Add a new profile to the NetBird client. The profile name must be unique.`,
 	Args:  cobra.ExactArgs(1),
 	RunE:  addProfileFunc,
@@ -38,16 +38,16 @@ var profileAddCmd = &cobra.Command{
 
 var profileRemoveCmd = &cobra.Command{
 	Use:   "remove <profile_name>",
-	Short: "Remove a profile",
-	Long:  `Remove a profile from the NetBird client. The profile must not be inactive.`,
+	Short: "remove a profile",
+	Long:  `Remove a profile from the NetBird client. The profile must not be active.`,
 	Args:  cobra.ExactArgs(1),
 	RunE:  removeProfileFunc,
 }
 
 var profileSelectCmd = &cobra.Command{
 	Use:   "select <profile_name>",
-	Short: "Select a profile",
-	Long:  `Make the specified profile active. This will switch the client to use the selected profile's configuration.`,
+	Short: "select a profile",
+	Long:  `Select a profile to be the active profile in the NetBird client. The profile must exist.`,
 	Args:  cobra.ExactArgs(1),
 	RunE:  selectProfileFunc,
 }

client/cmd/root.go

@@ -39,7 +39,6 @@ const (
 	extraIFaceBlackListFlag  = "extra-iface-blacklist"
 	dnsRouteIntervalFlag     = "dns-router-interval"
 	enableLazyConnectionFlag = "enable-lazy-connection"
-	mtuFlag                  = "mtu"
 )
 
 var (
@@ -73,9 +72,7 @@ var (
 	anonymizeFlag           bool
 	dnsRouteInterval        time.Duration
 	lazyConnEnabled         bool
-	mtu                     uint16
 	profilesDisabled        bool
-	updateSettingsDisabled  bool
 
 	rootCmd = &cobra.Command{
 		Use:          "netbird",
@@ -231,7 +228,7 @@ func FlagNameToEnvVar(cmdFlag string, prefix string) string {
 
 // DialClientGRPCServer returns client connection to the daemon server.
 func DialClientGRPCServer(ctx context.Context, addr string) (*grpc.ClientConn, error) {
-	ctx, cancel := context.WithTimeout(ctx, time.Second*10)
+	ctx, cancel := context.WithTimeout(ctx, time.Second*3)
 	defer cancel()
 
 	return grpc.DialContext(

client/cmd/root_test.go

@@ -54,7 +54,6 @@ func TestSetFlagsFromEnvVars(t *testing.T) {
 	cmd.PersistentFlags().StringVar(&interfaceName, interfaceNameFlag, iface.WgInterfaceDefault, "WireGuard interface name")
 	cmd.PersistentFlags().BoolVar(&rosenpassEnabled, enableRosenpassFlag, false, "Enable Rosenpass feature Rosenpass.")
 	cmd.PersistentFlags().Uint16Var(&wireguardPort, wireguardPortFlag, iface.DefaultWgPort, "WireGuard interface listening port")
-	cmd.PersistentFlags().Uint16Var(&mtu, mtuFlag, iface.DefaultMTU, "Set MTU (Maximum Transmission Unit) for the WireGuard interface")
 
 	t.Setenv("NB_EXTERNAL_IP_MAP", "abc,dec")
 	t.Setenv("NB_INTERFACE_NAME", "test-name")

client/cmd/service.go

@@ -19,7 +19,7 @@ import (
 
 var serviceCmd = &cobra.Command{
 	Use:   "service",
-	Short: "Manage the NetBird daemon service",
+	Short: "manages NetBird service",
 }
 
 var (
@@ -42,8 +42,7 @@ func init() {
 	}
 
 	serviceCmd.AddCommand(runCmd, startCmd, stopCmd, restartCmd, svcStatusCmd, installCmd, uninstallCmd, reconfigureCmd)
-	serviceCmd.PersistentFlags().BoolVar(&profilesDisabled, "disable-profiles", false, "Disables profiles feature. If enabled, the client will not be able to change or edit any profile. To persist this setting, use: netbird service install --disable-profiles")
-	serviceCmd.PersistentFlags().BoolVar(&updateSettingsDisabled, "disable-update-settings", false, "Disables update settings feature. If enabled, the client will not be able to change or edit any settings. To persist this setting, use: netbird service install --disable-update-settings")
+	serviceCmd.PersistentFlags().BoolVar(&profilesDisabled, "disable-profiles", false, "Disables profiles feature. If enabled, the client will not be able to change or edit any profile.")
 
 	rootCmd.PersistentFlags().StringVarP(&serviceName, "service", "s", defaultServiceName, "Netbird system service name")
 	serviceEnvDesc := `Sets extra environment variables for the service. ` +

client/cmd/service_controller.go

@@ -27,7 +27,7 @@ func (p *program) Start(svc service.Service) error {
 	log.Info("starting NetBird service") //nolint
 
 	// Collect static system and platform information
-	system.UpdateStaticInfoAsync()
+	system.UpdateStaticInfo()
 
 	// in any case, even if configuration does not exists we run daemon to serve CLI gRPC API.
 	p.serv = grpc.NewServer()
@@ -61,7 +61,7 @@ func (p *program) Start(svc service.Service) error {
 			}
 		}
 
-		serverInstance := server.New(p.ctx, util.FindFirstLogPath(logFiles), configPath, profilesDisabled, updateSettingsDisabled)
+		serverInstance := server.New(p.ctx, util.FindFirstLogPath(logFiles), configPath, profilesDisabled)
 		if err := serverInstance.Start(); err != nil {
 			log.Fatalf("failed to start daemon: %v", err)
 		}

client/cmd/service_installer.go

@@ -10,8 +10,6 @@ import (
 	"path/filepath"
 	"runtime"
 
-	log "github.com/sirupsen/logrus"
-
 	"github.com/kardianos/service"
 	"github.com/spf13/cobra"
 
@@ -51,14 +49,6 @@ func buildServiceArguments() []string {
 		args = append(args, "--log-file", logFile)
 	}
 
-	if profilesDisabled {
-		args = append(args, "--disable-profiles")
-	}
-
-	if updateSettingsDisabled {
-		args = append(args, "--disable-update-settings")
-	}
-
 	return args
 }
 
@@ -83,10 +73,6 @@ func configurePlatformSpecificSettings(svcConfig *service.Config) error {
 				svcConfig.Option["LogDirectory"] = dir
 			}
 		}
-
-		if err := configureSystemdNetworkd(); err != nil {
-			log.Warnf("failed to configure systemd-networkd: %v", err)
-		}
 	}
 
 	if runtime.GOOS == "windows" {
@@ -113,7 +99,7 @@ func createServiceConfigForInstall() (*service.Config, error) {
 
 var installCmd = &cobra.Command{
 	Use:   "install",
-	Short: "Install NetBird service",
+	Short: "installs NetBird service",
 	RunE: func(cmd *cobra.Command, args []string) error {
 		if err := setupServiceCommand(cmd); err != nil {
 			return err
@@ -166,12 +152,6 @@ var uninstallCmd = &cobra.Command{
 			return fmt.Errorf("uninstall service: %w", err)
 		}
 
-		if runtime.GOOS == "linux" {
-			if err := cleanupSystemdNetworkd(); err != nil {
-				log.Warnf("failed to cleanup systemd-networkd configuration: %v", err)
-			}
-		}
-
 		cmd.Println("NetBird service has been uninstalled")
 		return nil
 	},
@@ -257,50 +237,3 @@ func isServiceRunning() (bool, error) {
 
 	return status == service.StatusRunning, nil
 }
-
-const (
-	networkdConf        = "/etc/systemd/networkd.conf"
-	networkdConfDir     = "/etc/systemd/networkd.conf.d"
-	networkdConfFile    = "/etc/systemd/networkd.conf.d/99-netbird.conf"
-	networkdConfContent = `# Created by NetBird to prevent systemd-networkd from removing
-# routes and policy rules managed by NetBird.
-
-[Network]
-ManageForeignRoutes=no
-ManageForeignRoutingPolicyRules=no
-`
-)
-
-// configureSystemdNetworkd creates a drop-in configuration file to prevent
-// systemd-networkd from removing NetBird's routes and policy rules.
-func configureSystemdNetworkd() error {
-	if _, err := os.Stat(networkdConf); os.IsNotExist(err) {
-		log.Debug("systemd-networkd not in use, skipping configuration")
-		return nil
-	}
-
-	// nolint:gosec // standard networkd permissions
-	if err := os.MkdirAll(networkdConfDir, 0755); err != nil {
-		return fmt.Errorf("create networkd.conf.d directory: %w", err)
-	}
-
-	// nolint:gosec // standard networkd permissions
-	if err := os.WriteFile(networkdConfFile, []byte(networkdConfContent), 0644); err != nil {
-		return fmt.Errorf("write networkd configuration: %w", err)
-	}
-
-	return nil
-}
-
-// cleanupSystemdNetworkd removes the NetBird systemd-networkd configuration file.
-func cleanupSystemdNetworkd() error {
-	if _, err := os.Stat(networkdConfFile); os.IsNotExist(err) {
-		return nil
-	}
-
-	if err := os.Remove(networkdConfFile); err != nil {
-		return fmt.Errorf("remove networkd configuration: %w", err)
-	}
-
-	return nil
-}

client/cmd/ssh.go

@@ -40,7 +40,7 @@ var sshCmd = &cobra.Command{
 
 		return nil
 	},
-	Short: "Connect to a remote SSH server",
+	Short: "connect to a remote SSH server",
 	RunE: func(cmd *cobra.Command, args []string) error {
 		SetFlagsFromEnvVars(rootCmd)
 		SetFlagsFromEnvVars(cmd)

client/cmd/status.go

@@ -32,8 +32,7 @@ var (
 
 var statusCmd = &cobra.Command{
 	Use:   "status",
-	Short: "Display NetBird client status",
-	Long:  "Display the current status of the NetBird client, including connection status, peer information, and network details.",
+	Short: "status of the Netbird Service",
 	RunE:  statusFunc,
 }
 
@@ -68,7 +67,7 @@ func statusFunc(cmd *cobra.Command, args []string) error {
 
 	ctx := internal.CtxInitState(cmd.Context())
 
-	resp, err := getStatus(ctx, false)
+	resp, err := getStatus(ctx)
 	if err != nil {
 		return err
 	}
@@ -121,7 +120,7 @@ func statusFunc(cmd *cobra.Command, args []string) error {
 	return nil
 }
 
-func getStatus(ctx context.Context, shouldRunProbes bool) (*proto.StatusResponse, error) {
+func getStatus(ctx context.Context) (*proto.StatusResponse, error) {
 	conn, err := DialClientGRPCServer(ctx, daemonAddr)
 	if err != nil {
 		return nil, fmt.Errorf("failed to connect to daemon error: %v\n"+
@@ -130,7 +129,7 @@ func getStatus(ctx context.Context, shouldRunProbes bool) (*proto.StatusResponse
 	}
 	defer conn.Close()
 
-	resp, err := proto.NewDaemonServiceClient(conn).Status(ctx, &proto.StatusRequest{GetFullPeerStatus: true, ShouldRunProbes: shouldRunProbes})
+	resp, err := proto.NewDaemonServiceClient(conn).Status(ctx, &proto.StatusRequest{GetFullPeerStatus: true, ShouldRunProbes: true})
 	if err != nil {
 		return nil, fmt.Errorf("status failed: %v", status.Convert(err).Message())
 	}

client/cmd/testutil_test.go

@@ -9,33 +9,33 @@ import (
 	"github.com/golang/mock/gomock"
 	"github.com/stretchr/testify/require"
 	"go.opentelemetry.io/otel"
+
+	"github.com/netbirdio/netbird/management/server/activity"
+	"github.com/netbirdio/netbird/management/server/groups"
+	"github.com/netbirdio/netbird/management/server/integrations/port_forwarding"
+	"github.com/netbirdio/netbird/management/server/permissions"
+	"github.com/netbirdio/netbird/management/server/settings"
+	"github.com/netbirdio/netbird/management/server/store"
+	"github.com/netbirdio/netbird/management/server/telemetry"
+	"github.com/netbirdio/netbird/management/server/types"
+
+	"github.com/netbirdio/netbird/util"
+
 	"google.golang.org/grpc"
 
 	"github.com/netbirdio/management-integrations/integrations"
 
 	clientProto "github.com/netbirdio/netbird/client/proto"
 	client "github.com/netbirdio/netbird/client/server"
-	"github.com/netbirdio/netbird/management/internals/server/config"
-	mgmt "github.com/netbirdio/netbird/management/server"
-	"github.com/netbirdio/netbird/management/server/activity"
-	"github.com/netbirdio/netbird/management/server/groups"
-	"github.com/netbirdio/netbird/management/server/integrations/port_forwarding"
-	"github.com/netbirdio/netbird/management/server/peers"
-	"github.com/netbirdio/netbird/management/server/peers/ephemeral/manager"
-	"github.com/netbirdio/netbird/management/server/permissions"
-	"github.com/netbirdio/netbird/management/server/settings"
-	"github.com/netbirdio/netbird/management/server/store"
-	"github.com/netbirdio/netbird/management/server/telemetry"
-	"github.com/netbirdio/netbird/management/server/types"
 	mgmtProto "github.com/netbirdio/netbird/shared/management/proto"
+	mgmt "github.com/netbirdio/netbird/management/server"
 	sigProto "github.com/netbirdio/netbird/shared/signal/proto"
 	sig "github.com/netbirdio/netbird/signal/server"
-	"github.com/netbirdio/netbird/util"
 )
 
 func startTestingServices(t *testing.T) string {
 	t.Helper()
-	config := &config.Config{}
+	config := &types.Config{}
 	_, err := util.ReadJson("../testdata/management.json", config)
 	if err != nil {
 		t.Fatal(err)
@@ -70,7 +70,7 @@ func startSignal(t *testing.T) (*grpc.Server, net.Listener) {
 	return s, lis
 }
 
-func startManagement(t *testing.T, config *config.Config, testFile string) (*grpc.Server, net.Listener) {
+func startManagement(t *testing.T, config *types.Config, testFile string) (*grpc.Server, net.Listener) {
 	t.Helper()
 
 	lis, err := net.Listen("tcp", ":0")
@@ -89,20 +89,15 @@ func startManagement(t *testing.T, config *config.Config, testFile string) (*grp
 	if err != nil {
 		return nil, nil
 	}
-
-	ctrl := gomock.NewController(t)
-	t.Cleanup(ctrl.Finish)
-
-	permissionsManagerMock := permissions.NewMockManager(ctrl)
-	peersmanager := peers.NewManager(store, permissionsManagerMock)
-	settingsManagerMock := settings.NewMockManager(ctrl)
-
-	iv, _ := integrations.NewIntegratedValidator(context.Background(), peersmanager, settingsManagerMock, eventStore)
+	iv, _ := integrations.NewIntegratedValidator(context.Background(), eventStore)
 
 	metrics, err := telemetry.NewDefaultAppMetrics(context.Background())
 	require.NoError(t, err)
+	ctrl := gomock.NewController(t)
+	t.Cleanup(ctrl.Finish)
 
 	settingsMockManager := settings.NewMockManager(ctrl)
+	permissionsManagerMock := permissions.NewMockManager(ctrl)
 	groupsManager := groups.NewManagerMock()
 
 	settingsMockManager.EXPECT().
@@ -116,7 +111,7 @@ func startManagement(t *testing.T, config *config.Config, testFile string) (*grp
 	}
 
 	secretsManager := mgmt.NewTimeBasedAuthSecretsManager(peersUpdateManager, config.TURNConfig, config.Relay, settingsMockManager, groupsManager)
-	mgmtServer, err := mgmt.NewServer(context.Background(), config, accountManager, settingsMockManager, peersUpdateManager, secretsManager, nil, &manager.EphemeralManager{}, nil, &mgmt.MockIntegratedValidator{})
+	mgmtServer, err := mgmt.NewServer(context.Background(), config, accountManager, settingsMockManager, peersUpdateManager, secretsManager, nil, nil, nil, &mgmt.MockIntegratedValidator{})
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -141,7 +136,7 @@ func startClientDaemon(
 	s := grpc.NewServer()
 
 	server := client.New(ctx,
-		"", "", false, false)
+		"", "", false)
 	if err := server.Start(); err != nil {
 		t.Fatal(err)
 	}

client/cmd/up.go

@@ -53,8 +53,7 @@ var (
 
 	upCmd = &cobra.Command{
 		Use:   "up",
-		Short: "Connect to the NetBird network",
-		Long:  "Connect to the NetBird network using the provided setup key or SSO auth. This command will bring up the WireGuard interface, connect to the management server, and establish peer-to-peer connections with other peers in the network if required.",
+		Short: "install, login and start NetBird client",
 		RunE:  upFunc,
 	}
 )
@@ -63,7 +62,6 @@ func init() {
 	upCmd.PersistentFlags().BoolVarP(&foregroundMode, "foreground-mode", "F", false, "start service in foreground")
 	upCmd.PersistentFlags().StringVar(&interfaceName, interfaceNameFlag, iface.WgInterfaceDefault, "WireGuard interface name")
 	upCmd.PersistentFlags().Uint16Var(&wireguardPort, wireguardPortFlag, iface.DefaultWgPort, "WireGuard interface listening port")
-	upCmd.PersistentFlags().Uint16Var(&mtu, mtuFlag, iface.DefaultMTU, "Set MTU (Maximum Transmission Unit) for the WireGuard interface")
 	upCmd.PersistentFlags().BoolVarP(&networkMonitor, networkMonitorFlag, "N", networkMonitor,
 		`Manage network monitoring. Defaults to true on Windows and macOS, false on Linux and FreeBSD. `+
 			`E.g. --network-monitor=false to disable or --network-monitor=true to enable.`,
@@ -185,7 +183,7 @@ func runInForegroundMode(ctx context.Context, cmd *cobra.Command, activeProf *pr
 
 	_, _ = profilemanager.UpdateOldManagementURL(ctx, config, configFilePath)
 
-	err = foregroundLogin(ctx, cmd, config, providedSetupKey, activeProf.Name)
+	err = foregroundLogin(ctx, cmd, config, providedSetupKey)
 	if err != nil {
 		return fmt.Errorf("foreground login failed: %v", err)
 	}
@@ -230,9 +228,7 @@ func runInDaemonMode(ctx context.Context, cmd *cobra.Command, pm *profilemanager
 
 	client := proto.NewDaemonServiceClient(conn)
 
-	status, err := client.Status(ctx, &proto.StatusRequest{
-		WaitForReady: func() *bool { b := true; return &b }(),
-	})
+	status, err := client.Status(ctx, &proto.StatusRequest{})
 	if err != nil {
 		return fmt.Errorf("unable to get daemon status: %v", err)
 	}
@@ -286,13 +282,6 @@ func doDaemonUp(ctx context.Context, cmd *cobra.Command, client proto.DaemonServ
 	loginRequest.ProfileName = &activeProf.Name
 	loginRequest.Username = &username
 
-	profileState, err := pm.GetProfileState(activeProf.Name)
-	if err != nil {
-		log.Debugf("failed to get profile state for login hint: %v", err)
-	} else if profileState.Email != "" {
-		loginRequest.Hint = &profileState.Email
-	}
-
 	var loginErr error
 	var loginResp *proto.LoginResponse
 
@@ -367,11 +356,6 @@ func setupSetConfigReq(customDNSAddressConverted []byte, cmd *cobra.Command, pro
 		req.WireguardPort = &p
 	}
 
-	if cmd.Flag(mtuFlag).Changed {
-		m := int64(mtu)
-		req.Mtu = &m
-	}
-
 	if cmd.Flag(networkMonitorFlag).Changed {
 		req.NetworkMonitor = &networkMonitor
 	}
@@ -451,13 +435,6 @@ func setupConfig(customDNSAddressConverted []byte, cmd *cobra.Command, configFil
 		ic.WireguardPort = &p
 	}
 
-	if cmd.Flag(mtuFlag).Changed {
-		if err := iface.ValidateMTU(mtu); err != nil {
-			return nil, err
-		}
-		ic.MTU = &mtu
-	}
-
 	if cmd.Flag(networkMonitorFlag).Changed {
 		ic.NetworkMonitor = &networkMonitor
 	}
@@ -555,14 +532,6 @@ func setupLoginRequest(providedSetupKey string, customDNSAddressConverted []byte
 		loginRequest.WireguardPort = &wp
 	}
 
-	if cmd.Flag(mtuFlag).Changed {
-		if err := iface.ValidateMTU(mtu); err != nil {
-			return nil, err
-		}
-		m := int64(mtu)
-		loginRequest.Mtu = &m
-	}
-
 	if cmd.Flag(networkMonitorFlag).Changed {
 		loginRequest.NetworkMonitor = &networkMonitor
 	}

client/cmd/version.go

@@ -9,7 +9,7 @@ import (
 var (
 	versionCmd = &cobra.Command{
 		Use:   "version",
-		Short: "Print the NetBird's client application version",
+		Short: "prints NetBird version",
 		Run: func(cmd *cobra.Command, args []string) {
 			cmd.SetOut(cmd.OutOrStdout())
 			cmd.Println(version.NetbirdVersion())

client/embed/embed.go

@@ -23,29 +23,23 @@ import (
 
 var ErrClientAlreadyStarted = errors.New("client already started")
 var ErrClientNotStarted = errors.New("client not started")
-var ErrConfigNotInitialized = errors.New("config not initialized")
 
-// Client manages a netbird embedded client instance.
+// Client manages a netbird embedded client instance
 type Client struct {
 	deviceName string
 	config     *profilemanager.Config
 	mu         sync.Mutex
 	cancel     context.CancelFunc
 	setupKey   string
-	jwtToken   string
 	connect    *internal.ConnectClient
 }
 
-// Options configures a new Client.
+// Options configures a new Client
 type Options struct {
 	// DeviceName is this peer's name in the network
 	DeviceName string
 	// SetupKey is used for authentication
 	SetupKey string
-	// JWTToken is used for JWT-based authentication
-	JWTToken string
-	// PrivateKey is used for direct private key authentication
-	PrivateKey string
 	// ManagementURL overrides the default management server URL
 	ManagementURL string
 	// PreSharedKey is the pre-shared key for the WireGuard interface
@@ -64,35 +58,8 @@ type Options struct {
 	DisableClientRoutes bool
 }
 
-// validateCredentials checks that exactly one credential type is provided
-func (opts *Options) validateCredentials() error {
-	credentialsProvided := 0
-	if opts.SetupKey != "" {
-		credentialsProvided++
-	}
-	if opts.JWTToken != "" {
-		credentialsProvided++
-	}
-	if opts.PrivateKey != "" {
-		credentialsProvided++
-	}
-
-	if credentialsProvided == 0 {
-		return fmt.Errorf("one of SetupKey, JWTToken, or PrivateKey must be provided")
-	}
-	if credentialsProvided > 1 {
-		return fmt.Errorf("only one of SetupKey, JWTToken, or PrivateKey can be specified")
-	}
-
-	return nil
-}
-
-// New creates a new netbird embedded client.
+// New creates a new netbird embedded client
 func New(opts Options) (*Client, error) {
-	if err := opts.validateCredentials(); err != nil {
-		return nil, err
-	}
-
 	if opts.LogOutput != nil {
 		logrus.SetOutput(opts.LogOutput)
 	}
@@ -140,14 +107,9 @@ func New(opts Options) (*Client, error) {
 		return nil, fmt.Errorf("create config: %w", err)
 	}
 
-	if opts.PrivateKey != "" {
-		config.PrivateKey = opts.PrivateKey
-	}
-
 	return &Client{
 		deviceName: opts.DeviceName,
 		setupKey:   opts.SetupKey,
-		jwtToken:   opts.JWTToken,
 		config:     config,
 	}, nil
 }
@@ -164,7 +126,7 @@ func (c *Client) Start(startCtx context.Context) error {
 	ctx := internal.CtxInitState(context.Background())
 	// nolint:staticcheck
 	ctx = context.WithValue(ctx, system.DeviceNameCtxKey, c.deviceName)
-	if err := internal.Login(ctx, c.config, c.setupKey, c.jwtToken); err != nil {
+	if err := internal.Login(ctx, c.config, c.setupKey, ""); err != nil {
 		return fmt.Errorf("login: %w", err)
 	}
 
@@ -173,7 +135,7 @@ func (c *Client) Start(startCtx context.Context) error {
 
 	// either startup error (permanent backoff err) or nil err (successful engine up)
 	// TODO: make after-startup backoff err available
-	run := make(chan struct{})
+	run := make(chan struct{}, 1)
 	clientErr := make(chan error, 1)
 	go func() {
 		if err := client.Run(run); err != nil {
@@ -225,16 +187,6 @@ func (c *Client) Stop(ctx context.Context) error {
 	}
 }
 
-// GetConfig returns a copy of the internal client config.
-func (c *Client) GetConfig() (profilemanager.Config, error) {
-	c.mu.Lock()
-	defer c.mu.Unlock()
-	if c.config == nil {
-		return profilemanager.Config{}, ErrConfigNotInitialized
-	}
-	return *c.config, nil
-}
-
 // Dial dials a network address in the netbird network.
 // Not applicable if the userspace networking mode is disabled.
 func (c *Client) Dial(ctx context.Context, network, address string) (net.Conn, error) {
@@ -259,7 +211,7 @@ func (c *Client) Dial(ctx context.Context, network, address string) (net.Conn, e
 	return nsnet.DialContext(ctx, network, address)
 }
 
-// ListenTCP listens on the given address in the netbird network.
+// ListenTCP listens on the given address in the netbird network
 // Not applicable if the userspace networking mode is disabled.
 func (c *Client) ListenTCP(address string) (net.Listener, error) {
 	nsnet, addr, err := c.getNet()
@@ -280,7 +232,7 @@ func (c *Client) ListenTCP(address string) (net.Listener, error) {
 	return nsnet.ListenTCP(tcpAddr)
 }
 
-// ListenUDP listens on the given address in the netbird network.
+// ListenUDP listens on the given address in the netbird network
 // Not applicable if the userspace networking mode is disabled.
 func (c *Client) ListenUDP(address string) (net.PacketConn, error) {
 	nsnet, addr, err := c.getNet()

client/firewall/create.go

@@ -15,13 +15,13 @@ import (
 )
 
 // NewFirewall creates a firewall manager instance
-func NewFirewall(iface IFaceMapper, _ *statemanager.Manager, flowLogger nftypes.FlowLogger, disableServerRoutes bool, mtu uint16) (firewall.Manager, error) {
+func NewFirewall(iface IFaceMapper, _ *statemanager.Manager, flowLogger nftypes.FlowLogger, disableServerRoutes bool) (firewall.Manager, error) {
 	if !iface.IsUserspaceBind() {
 		return nil, fmt.Errorf("not implemented for this OS: %s", runtime.GOOS)
 	}
 
 	// use userspace packet filtering firewall
-	fm, err := uspfilter.Create(iface, disableServerRoutes, flowLogger, mtu)
+	fm, err := uspfilter.Create(iface, disableServerRoutes, flowLogger)
 	if err != nil {
 		return nil, err
 	}

client/firewall/create_linux.go

@@ -34,12 +34,12 @@ const SKIP_NFTABLES_ENV = "NB_SKIP_NFTABLES_CHECK"
 // FWType is the type for the firewall type
 type FWType int
 
-func NewFirewall(iface IFaceMapper, stateManager *statemanager.Manager, flowLogger nftypes.FlowLogger, disableServerRoutes bool, mtu uint16) (firewall.Manager, error) {
+func NewFirewall(iface IFaceMapper, stateManager *statemanager.Manager, flowLogger nftypes.FlowLogger, disableServerRoutes bool) (firewall.Manager, error) {
 	// on the linux system we try to user nftables or iptables
 	// in any case, because we need to allow netbird interface traffic
 	// so we use AllowNetbird traffic from these firewall managers
 	// for the userspace packet filtering firewall
-	fm, err := createNativeFirewall(iface, stateManager, disableServerRoutes, mtu)
+	fm, err := createNativeFirewall(iface, stateManager, disableServerRoutes)
 
 	if !iface.IsUserspaceBind() {
 		return fm, err
@@ -48,11 +48,11 @@ func NewFirewall(iface IFaceMapper, stateManager *statemanager.Manager, flowLogg
 	if err != nil {
 		log.Warnf("failed to create native firewall: %v. Proceeding with userspace", err)
 	}
-	return createUserspaceFirewall(iface, fm, disableServerRoutes, flowLogger, mtu)
+	return createUserspaceFirewall(iface, fm, disableServerRoutes, flowLogger)
 }
 
-func createNativeFirewall(iface IFaceMapper, stateManager *statemanager.Manager, routes bool, mtu uint16) (firewall.Manager, error) {
-	fm, err := createFW(iface, mtu)
+func createNativeFirewall(iface IFaceMapper, stateManager *statemanager.Manager, routes bool) (firewall.Manager, error) {
+	fm, err := createFW(iface)
 	if err != nil {
 		return nil, fmt.Errorf("create firewall: %s", err)
 	}
@@ -64,26 +64,26 @@ func createNativeFirewall(iface IFaceMapper, stateManager *statemanager.Manager,
 	return fm, nil
 }
 
-func createFW(iface IFaceMapper, mtu uint16) (firewall.Manager, error) {
+func createFW(iface IFaceMapper) (firewall.Manager, error) {
 	switch check() {
 	case IPTABLES:
 		log.Info("creating an iptables firewall manager")
-		return nbiptables.Create(iface, mtu)
+		return nbiptables.Create(iface)
 	case NFTABLES:
 		log.Info("creating an nftables firewall manager")
-		return nbnftables.Create(iface, mtu)
+		return nbnftables.Create(iface)
 	default:
 		log.Info("no firewall manager found, trying to use userspace packet filtering firewall")
 		return nil, errors.New("no firewall manager found")
 	}
 }
 
-func createUserspaceFirewall(iface IFaceMapper, fm firewall.Manager, disableServerRoutes bool, flowLogger nftypes.FlowLogger, mtu uint16) (firewall.Manager, error) {
+func createUserspaceFirewall(iface IFaceMapper, fm firewall.Manager, disableServerRoutes bool, flowLogger nftypes.FlowLogger) (firewall.Manager, error) {
 	var errUsp error
 	if fm != nil {
-		fm, errUsp = uspfilter.CreateWithNativeFirewall(iface, fm, disableServerRoutes, flowLogger, mtu)
+		fm, errUsp = uspfilter.CreateWithNativeFirewall(iface, fm, disableServerRoutes, flowLogger)
 	} else {
-		fm, errUsp = uspfilter.Create(iface, disableServerRoutes, flowLogger, mtu)
+		fm, errUsp = uspfilter.Create(iface, disableServerRoutes, flowLogger)
 	}
 
 	if errUsp != nil {

client/firewall/iptables/acl_linux.go

@@ -12,7 +12,7 @@ import (
 
 	firewall "github.com/netbirdio/netbird/client/firewall/manager"
 	"github.com/netbirdio/netbird/client/internal/statemanager"
-	nbnet "github.com/netbirdio/netbird/client/net"
+	nbnet "github.com/netbirdio/netbird/util/net"
 )
 
 const (
@@ -85,7 +85,7 @@ func (m *aclManager) AddPeerFiltering(
 ) ([]firewall.Rule, error) {
 	chain := chainNameInputRules
 
-	ipsetName = transformIPsetName(ipsetName, sPort, dPort, action)
+	ipsetName = transformIPsetName(ipsetName, sPort, dPort)
 	specs := filterRuleSpecs(ip, string(protocol), sPort, dPort, action, ipsetName)
 
 	mangleSpecs := slices.Clone(specs)
@@ -135,14 +135,7 @@ func (m *aclManager) AddPeerFiltering(
 		return nil, fmt.Errorf("rule already exists")
 	}
 
-	// Insert DROP rules at the beginning, append ACCEPT rules at the end
-	if action == firewall.ActionDrop {
-		// Insert at the beginning of the chain (position 1)
-		err = m.iptablesClient.Insert(tableFilter, chain, 1, specs...)
-	} else {
-		err = m.iptablesClient.Append(tableFilter, chain, specs...)
-	}
-	if err != nil {
+	if err := m.iptablesClient.Append(tableFilter, chain, specs...); err != nil {
 		return nil, err
 	}
 
@@ -395,24 +388,17 @@ func actionToStr(action firewall.Action) string {
 	return "DROP"
 }
 
-func transformIPsetName(ipsetName string, sPort, dPort *firewall.Port, action firewall.Action) string {
-	if ipsetName == "" {
-		return ""
-	}
-
-	actionSuffix := ""
-	if action == firewall.ActionDrop {
-		actionSuffix = "-drop"
-	}
-
+func transformIPsetName(ipsetName string, sPort, dPort *firewall.Port) string {
 	switch {
+	case ipsetName == "":
+		return ""
 	case sPort != nil && dPort != nil:
-		return ipsetName + "-sport-dport" + actionSuffix
+		return ipsetName + "-sport-dport"
 	case sPort != nil:
-		return ipsetName + "-sport" + actionSuffix
+		return ipsetName + "-sport"
 	case dPort != nil:
-		return ipsetName + "-dport" + actionSuffix
+		return ipsetName + "-dport"
 	default:
-		return ipsetName + actionSuffix
+		return ipsetName
 	}
 }

client/firewall/iptables/manager_linux.go

@@ -36,7 +36,7 @@ type iFaceMapper interface {
 }
 
 // Create iptables firewall manager
-func Create(wgIface iFaceMapper, mtu uint16) (*Manager, error) {
+func Create(wgIface iFaceMapper) (*Manager, error) {
 	iptablesClient, err := iptables.NewWithProtocol(iptables.ProtocolIPv4)
 	if err != nil {
 		return nil, fmt.Errorf("init iptables: %w", err)
@@ -47,7 +47,7 @@ func Create(wgIface iFaceMapper, mtu uint16) (*Manager, error) {
 		ipv4Client: iptablesClient,
 	}
 
-	m.router, err = newRouter(iptablesClient, wgIface, mtu)
+	m.router, err = newRouter(iptablesClient, wgIface)
 	if err != nil {
 		return nil, fmt.Errorf("create router: %w", err)
 	}
@@ -66,7 +66,6 @@ func (m *Manager) Init(stateManager *statemanager.Manager) error {
 			NameStr:       m.wgIface.Name(),
 			WGAddress:     m.wgIface.Address(),
 			UserspaceBind: m.wgIface.IsUserspaceBind(),
-			MTU:           m.router.mtu,
 		},
 	}
 	stateManager.RegisterState(state)
@@ -261,22 +260,6 @@ func (m *Manager) UpdateSet(set firewall.Set, prefixes []netip.Prefix) error {
 	return m.router.UpdateSet(set, prefixes)
 }
 
-// AddInboundDNAT adds an inbound DNAT rule redirecting traffic from NetBird peers to local services.
-func (m *Manager) AddInboundDNAT(localAddr netip.Addr, protocol firewall.Protocol, sourcePort, targetPort uint16) error {
-	m.mutex.Lock()
-	defer m.mutex.Unlock()
-
-	return m.router.AddInboundDNAT(localAddr, protocol, sourcePort, targetPort)
-}
-
-// RemoveInboundDNAT removes an inbound DNAT rule.
-func (m *Manager) RemoveInboundDNAT(localAddr netip.Addr, protocol firewall.Protocol, sourcePort, targetPort uint16) error {
-	m.mutex.Lock()
-	defer m.mutex.Unlock()
-
-	return m.router.RemoveInboundDNAT(localAddr, protocol, sourcePort, targetPort)
-}
-
 func getConntrackEstablished() []string {
 	return []string{"-m", "conntrack", "--ctstate", "RELATED,ESTABLISHED", "-j", "ACCEPT"}
 }

client/firewall/iptables/manager_linux_test.go

@@ -3,7 +3,6 @@ package iptables
 import (
 	"fmt"
 	"net/netip"
-	"strings"
 	"testing"
 	"time"
 
@@ -11,13 +10,12 @@ import (
 	"github.com/stretchr/testify/require"
 
 	fw "github.com/netbirdio/netbird/client/firewall/manager"
-	"github.com/netbirdio/netbird/client/iface"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
 )
 
 var ifaceMock = &iFaceMock{
 	NameFunc: func() string {
-		return "wg-test"
+		return "lo"
 	},
 	AddressFunc: func() wgaddr.Address {
 		return wgaddr.Address{
@@ -54,7 +52,7 @@ func TestIptablesManager(t *testing.T) {
 	require.NoError(t, err)
 
 	// just check on the local interface
-	manager, err := Create(ifaceMock, iface.DefaultMTU)
+	manager, err := Create(ifaceMock)
 	require.NoError(t, err)
 	require.NoError(t, manager.Init(nil))
 
@@ -111,84 +109,10 @@ func TestIptablesManager(t *testing.T) {
 	})
 }
 
-func TestIptablesManagerDenyRules(t *testing.T) {
-	ipv4Client, err := iptables.NewWithProtocol(iptables.ProtocolIPv4)
-	require.NoError(t, err)
-
-	manager, err := Create(ifaceMock, iface.DefaultMTU)
-	require.NoError(t, err)
-	require.NoError(t, manager.Init(nil))
-
-	defer func() {
-		err := manager.Close(nil)
-		require.NoError(t, err)
-	}()
-
-	t.Run("add deny rule", func(t *testing.T) {
-		ip := netip.MustParseAddr("10.20.0.3")
-		port := &fw.Port{Values: []uint16{22}}
-
-		rule, err := manager.AddPeerFiltering(nil, ip.AsSlice(), "tcp", nil, port, fw.ActionDrop, "deny-ssh")
-		require.NoError(t, err, "failed to add deny rule")
-		require.NotEmpty(t, rule, "deny rule should not be empty")
-
-		// Verify the rule was added by checking iptables
-		for _, r := range rule {
-			rr := r.(*Rule)
-			checkRuleSpecs(t, ipv4Client, rr.chain, true, rr.specs...)
-		}
-	})
-
-	t.Run("deny rule precedence test", func(t *testing.T) {
-		ip := netip.MustParseAddr("10.20.0.4")
-		port := &fw.Port{Values: []uint16{80}}
-
-		// Add accept rule first
-		_, err := manager.AddPeerFiltering(nil, ip.AsSlice(), "tcp", nil, port, fw.ActionAccept, "accept-http")
-		require.NoError(t, err, "failed to add accept rule")
-
-		// Add deny rule second for same IP/port - this should take precedence
-		_, err = manager.AddPeerFiltering(nil, ip.AsSlice(), "tcp", nil, port, fw.ActionDrop, "deny-http")
-		require.NoError(t, err, "failed to add deny rule")
-
-		// Inspect the actual iptables rules to verify deny rule comes before accept rule
-		rules, err := ipv4Client.List("filter", chainNameInputRules)
-		require.NoError(t, err, "failed to list iptables rules")
-
-		// Debug: print all rules
-		t.Logf("All iptables rules in chain %s:", chainNameInputRules)
-		for i, rule := range rules {
-			t.Logf("  [%d] %s", i, rule)
-		}
-
-		var denyRuleIndex, acceptRuleIndex int = -1, -1
-		for i, rule := range rules {
-			if strings.Contains(rule, "DROP") {
-				t.Logf("Found DROP rule at index %d: %s", i, rule)
-				if strings.Contains(rule, "deny-http") && strings.Contains(rule, "80") {
-					denyRuleIndex = i
-				}
-			}
-			if strings.Contains(rule, "ACCEPT") {
-				t.Logf("Found ACCEPT rule at index %d: %s", i, rule)
-				if strings.Contains(rule, "accept-http") && strings.Contains(rule, "80") {
-					acceptRuleIndex = i
-				}
-			}
-		}
-
-		require.NotEqual(t, -1, denyRuleIndex, "deny rule should exist in iptables")
-		require.NotEqual(t, -1, acceptRuleIndex, "accept rule should exist in iptables")
-		require.Less(t, denyRuleIndex, acceptRuleIndex,
-			"deny rule should come before accept rule in iptables chain (deny at index %d, accept at index %d)",
-			denyRuleIndex, acceptRuleIndex)
-	})
-}
-
 func TestIptablesManagerIPSet(t *testing.T) {
 	mock := &iFaceMock{
 		NameFunc: func() string {
-			return "wg-test"
+			return "lo"
 		},
 		AddressFunc: func() wgaddr.Address {
 			return wgaddr.Address{
@@ -199,7 +123,7 @@ func TestIptablesManagerIPSet(t *testing.T) {
 	}
 
 	// just check on the local interface
-	manager, err := Create(mock, iface.DefaultMTU)
+	manager, err := Create(mock)
 	require.NoError(t, err)
 	require.NoError(t, manager.Init(nil))
 
@@ -252,7 +176,7 @@ func checkRuleSpecs(t *testing.T, ipv4Client *iptables.IPTables, chainName strin
 func TestIptablesCreatePerformance(t *testing.T) {
 	mock := &iFaceMock{
 		NameFunc: func() string {
-			return "wg-test"
+			return "lo"
 		},
 		AddressFunc: func() wgaddr.Address {
 			return wgaddr.Address{
@@ -265,7 +189,7 @@ func TestIptablesCreatePerformance(t *testing.T) {
 	for _, testMax := range []int{10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000} {
 		t.Run(fmt.Sprintf("Testing %d rules", testMax), func(t *testing.T) {
 			// just check on the local interface
-			manager, err := Create(mock, iface.DefaultMTU)
+			manager, err := Create(mock)
 			require.NoError(t, err)
 			require.NoError(t, manager.Init(nil))
 			time.Sleep(time.Second)

client/firewall/iptables/router_linux.go

@@ -19,7 +19,7 @@ import (
 	"github.com/netbirdio/netbird/client/internal/routemanager/ipfwdstate"
 	"github.com/netbirdio/netbird/client/internal/routemanager/refcounter"
 	"github.com/netbirdio/netbird/client/internal/statemanager"
-	nbnet "github.com/netbirdio/netbird/client/net"
+	nbnet "github.com/netbirdio/netbird/util/net"
 )
 
 // constants needed to manage and create iptable rules
@@ -30,20 +30,17 @@ const (
 
 	chainPOSTROUTING        = "POSTROUTING"
 	chainPREROUTING         = "PREROUTING"
-	chainFORWARD            = "FORWARD"
 	chainRTNAT              = "NETBIRD-RT-NAT"
 	chainRTFWDIN            = "NETBIRD-RT-FWD-IN"
 	chainRTFWDOUT           = "NETBIRD-RT-FWD-OUT"
 	chainRTPRE              = "NETBIRD-RT-PRE"
 	chainRTRDR              = "NETBIRD-RT-RDR"
-	chainRTMSSCLAMP         = "NETBIRD-RT-MSSCLAMP"
 	routingFinalForwardJump = "ACCEPT"
 	routingFinalNatJump     = "MASQUERADE"
 
 	jumpManglePre  = "jump-mangle-pre"
 	jumpNatPre     = "jump-nat-pre"
 	jumpNatPost    = "jump-nat-post"
-	jumpMSSClamp   = "jump-mss-clamp"
 	markManglePre  = "mark-mangle-pre"
 	markManglePost = "mark-mangle-post"
 	matchSet       = "--match-set"
@@ -51,9 +48,6 @@ const (
 	dnatSuffix = "_dnat"
 	snatSuffix = "_snat"
 	fwdSuffix  = "_fwd"
-
-	// ipTCPHeaderMinSize represents minimum IP (20) + TCP (20) header size for MSS calculation
-	ipTCPHeaderMinSize = 40
 )
 
 type ruleInfo struct {
@@ -83,18 +77,16 @@ type router struct {
 	ipsetCounter     *ipsetCounter
 	wgIface          iFaceMapper
 	legacyManagement bool
-	mtu              uint16
 
 	stateManager *statemanager.Manager
 	ipFwdState   *ipfwdstate.IPForwardingState
 }
 
-func newRouter(iptablesClient *iptables.IPTables, wgIface iFaceMapper, mtu uint16) (*router, error) {
+func newRouter(iptablesClient *iptables.IPTables, wgIface iFaceMapper) (*router, error) {
 	r := &router{
 		iptablesClient: iptablesClient,
 		rules:          make(map[string][]string),
 		wgIface:        wgIface,
-		mtu:            mtu,
 		ipFwdState:     ipfwdstate.NewIPForwardingState(),
 	}
 
@@ -400,7 +392,6 @@ func (r *router) cleanUpDefaultForwardRules() error {
 		{chainRTPRE, tableMangle},
 		{chainRTNAT, tableNat},
 		{chainRTRDR, tableNat},
-		{chainRTMSSCLAMP, tableMangle},
 	} {
 		ok, err := r.iptablesClient.ChainExists(chainInfo.table, chainInfo.chain)
 		if err != nil {
@@ -425,7 +416,6 @@ func (r *router) createContainers() error {
 		{chainRTPRE, tableMangle},
 		{chainRTNAT, tableNat},
 		{chainRTRDR, tableNat},
-		{chainRTMSSCLAMP, tableMangle},
 	} {
 		if err := r.iptablesClient.NewChain(chainInfo.table, chainInfo.chain); err != nil {
 			return fmt.Errorf("create chain %s in table %s: %w", chainInfo.chain, chainInfo.table, err)
@@ -448,10 +438,6 @@ func (r *router) createContainers() error {
 		return fmt.Errorf("add jump rules: %w", err)
 	}
 
-	if err := r.addMSSClampingRules(); err != nil {
-		log.Errorf("failed to add MSS clamping rules: %s", err)
-	}
-
 	return nil
 }
 
@@ -532,35 +518,6 @@ func (r *router) addPostroutingRules() error {
 	return nil
 }
 
-// addMSSClampingRules adds MSS clamping rules to prevent fragmentation for forwarded traffic.
-// TODO: Add IPv6 support
-func (r *router) addMSSClampingRules() error {
-	mss := r.mtu - ipTCPHeaderMinSize
-
-	// Add jump rule from FORWARD chain in mangle table to our custom chain
-	jumpRule := []string{
-		"-j", chainRTMSSCLAMP,
-	}
-	if err := r.iptablesClient.Insert(tableMangle, chainFORWARD, 1, jumpRule...); err != nil {
-		return fmt.Errorf("add jump to MSS clamp chain: %w", err)
-	}
-	r.rules[jumpMSSClamp] = jumpRule
-
-	ruleOut := []string{
-		"-o", r.wgIface.Name(),
-		"-p", "tcp",
-		"--tcp-flags", "SYN,RST", "SYN",
-		"-j", "TCPMSS",
-		"--set-mss", fmt.Sprintf("%d", mss),
-	}
-	if err := r.iptablesClient.Append(tableMangle, chainRTMSSCLAMP, ruleOut...); err != nil {
-		return fmt.Errorf("add outbound MSS clamp rule: %w", err)
-	}
-	r.rules["mss-clamp-out"] = ruleOut
-
-	return nil
-}
-
 func (r *router) insertEstablishedRule(chain string) error {
 	establishedRule := getConntrackEstablished()
 
@@ -601,7 +558,7 @@ func (r *router) addJumpRules() error {
 }
 
 func (r *router) cleanJumpRules() error {
-	for _, ruleKey := range []string{jumpNatPost, jumpManglePre, jumpNatPre, jumpMSSClamp} {
+	for _, ruleKey := range []string{jumpNatPost, jumpManglePre, jumpNatPre} {
 		if rule, exists := r.rules[ruleKey]; exists {
 			var table, chain string
 			switch ruleKey {
@@ -614,9 +571,6 @@ func (r *router) cleanJumpRules() error {
 			case jumpNatPre:
 				table = tableNat
 				chain = chainPREROUTING
-			case jumpMSSClamp:
-				table = tableMangle
-				chain = chainFORWARD
 			default:
 				return fmt.Errorf("unknown jump rule: %s", ruleKey)
 			}
@@ -926,54 +880,6 @@ func (r *router) UpdateSet(set firewall.Set, prefixes []netip.Prefix) error {
 	return nberrors.FormatErrorOrNil(merr)
 }
 
-// AddInboundDNAT adds an inbound DNAT rule redirecting traffic from NetBird peers to local services.
-func (r *router) AddInboundDNAT(localAddr netip.Addr, protocol firewall.Protocol, sourcePort, targetPort uint16) error {
-	ruleID := fmt.Sprintf("inbound-dnat-%s-%s-%d-%d", localAddr.String(), protocol, sourcePort, targetPort)
-
-	if _, exists := r.rules[ruleID]; exists {
-		return nil
-	}
-
-	dnatRule := []string{
-		"-i", r.wgIface.Name(),
-		"-p", strings.ToLower(string(protocol)),
-		"--dport", strconv.Itoa(int(sourcePort)),
-		"-d", localAddr.String(),
-		"-m", "addrtype", "--dst-type", "LOCAL",
-		"-j", "DNAT",
-		"--to-destination", ":" + strconv.Itoa(int(targetPort)),
-	}
-
-	ruleInfo := ruleInfo{
-		table: tableNat,
-		chain: chainRTRDR,
-		rule:  dnatRule,
-	}
-
-	if err := r.iptablesClient.Append(ruleInfo.table, ruleInfo.chain, ruleInfo.rule...); err != nil {
-		return fmt.Errorf("add inbound DNAT rule: %w", err)
-	}
-	r.rules[ruleID] = ruleInfo.rule
-
-	r.updateState()
-	return nil
-}
-
-// RemoveInboundDNAT removes an inbound DNAT rule.
-func (r *router) RemoveInboundDNAT(localAddr netip.Addr, protocol firewall.Protocol, sourcePort, targetPort uint16) error {
-	ruleID := fmt.Sprintf("inbound-dnat-%s-%s-%d-%d", localAddr.String(), protocol, sourcePort, targetPort)
-
-	if dnatRule, exists := r.rules[ruleID]; exists {
-		if err := r.iptablesClient.Delete(tableNat, chainRTRDR, dnatRule...); err != nil {
-			return fmt.Errorf("delete inbound DNAT rule: %w", err)
-		}
-		delete(r.rules, ruleID)
-	}
-
-	r.updateState()
-	return nil
-}
-
 func applyPort(flag string, port *firewall.Port) []string {
 	if port == nil {
 		return nil

client/firewall/iptables/router_linux_test.go

@@ -14,8 +14,7 @@ import (
 
 	firewall "github.com/netbirdio/netbird/client/firewall/manager"
 	"github.com/netbirdio/netbird/client/firewall/test"
-	"github.com/netbirdio/netbird/client/iface"
-	nbnet "github.com/netbirdio/netbird/client/net"
+	nbnet "github.com/netbirdio/netbird/util/net"
 )
 
 func isIptablesSupported() bool {
@@ -31,7 +30,7 @@ func TestIptablesManager_RestoreOrCreateContainers(t *testing.T) {
 	iptablesClient, err := iptables.NewWithProtocol(iptables.ProtocolIPv4)
 	require.NoError(t, err, "failed to init iptables client")
 
-	manager, err := newRouter(iptablesClient, ifaceMock, iface.DefaultMTU)
+	manager, err := newRouter(iptablesClient, ifaceMock)
 	require.NoError(t, err, "should return a valid iptables manager")
 	require.NoError(t, manager.init(nil))
 
@@ -39,6 +38,7 @@ func TestIptablesManager_RestoreOrCreateContainers(t *testing.T) {
 		assert.NoError(t, manager.Reset(), "shouldn't return error")
 	}()
 
+	// Now 5 rules:
 	// 1. established rule forward in
 	// 2. estbalished rule forward out
 	// 3. jump rule to POST nat chain
@@ -48,9 +48,7 @@ func TestIptablesManager_RestoreOrCreateContainers(t *testing.T) {
 	// 7. static return masquerade rule
 	// 8. mangle prerouting mark rule
 	// 9. mangle postrouting mark rule
-	// 10. jump rule to MSS clamping chain
-	// 11. MSS clamping rule for outbound traffic
-	require.Len(t, manager.rules, 11, "should have created rules map")
+	require.Len(t, manager.rules, 9, "should have created rules map")
 
 	exists, err := manager.iptablesClient.Exists(tableNat, chainPOSTROUTING, "-j", chainRTNAT)
 	require.NoError(t, err, "should be able to query the iptables %s table and %s chain", tableNat, chainPOSTROUTING)
@@ -84,7 +82,7 @@ func TestIptablesManager_AddNatRule(t *testing.T) {
 			iptablesClient, err := iptables.NewWithProtocol(iptables.ProtocolIPv4)
 			require.NoError(t, err, "failed to init iptables client")
 
-			manager, err := newRouter(iptablesClient, ifaceMock, iface.DefaultMTU)
+			manager, err := newRouter(iptablesClient, ifaceMock)
 			require.NoError(t, err, "shouldn't return error")
 			require.NoError(t, manager.init(nil))
 
@@ -157,7 +155,7 @@ func TestIptablesManager_RemoveNatRule(t *testing.T) {
 		t.Run(testCase.Name, func(t *testing.T) {
 			iptablesClient, _ := iptables.NewWithProtocol(iptables.ProtocolIPv4)
 
-			manager, err := newRouter(iptablesClient, ifaceMock, iface.DefaultMTU)
+			manager, err := newRouter(iptablesClient, ifaceMock)
 			require.NoError(t, err, "shouldn't return error")
 			require.NoError(t, manager.init(nil))
 			defer func() {
@@ -219,7 +217,7 @@ func TestRouter_AddRouteFiltering(t *testing.T) {
 	iptablesClient, err := iptables.NewWithProtocol(iptables.ProtocolIPv4)
 	require.NoError(t, err, "Failed to create iptables client")
 
-	r, err := newRouter(iptablesClient, ifaceMock, iface.DefaultMTU)
+	r, err := newRouter(iptablesClient, ifaceMock)
 	require.NoError(t, err, "Failed to create router manager")
 	require.NoError(t, r.init(nil))
 

client/firewall/iptables/state_linux.go

@@ -4,7 +4,6 @@ import (
 	"fmt"
 	"sync"
 
-	"github.com/netbirdio/netbird/client/iface"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
 )
 
@@ -12,7 +11,6 @@ type InterfaceState struct {
 	NameStr       string         `json:"name"`
 	WGAddress     wgaddr.Address `json:"wg_address"`
 	UserspaceBind bool           `json:"userspace_bind"`
-	MTU           uint16         `json:"mtu"`
 }
 
 func (i *InterfaceState) Name() string {
@@ -44,11 +42,7 @@ func (s *ShutdownState) Name() string {
 }
 
 func (s *ShutdownState) Cleanup() error {
-	mtu := s.InterfaceState.MTU
-	if mtu == 0 {
-		mtu = iface.DefaultMTU
-	}
-	ipt, err := Create(s.InterfaceState, mtu)
+	ipt, err := Create(s.InterfaceState)
 	if err != nil {
 		return fmt.Errorf("create iptables manager: %w", err)
 	}

client/firewall/manager/firewall.go

@@ -100,9 +100,6 @@ type Manager interface {
 	//
 	// If comment argument is empty firewall manager should set
 	// rule ID as comment for the rule
-	//
-	// Note: Callers should call Flush() after adding rules to ensure
-	// they are applied to the kernel and rule handles are refreshed.
 	AddPeerFiltering(
 		id []byte,
 		ip net.IP,
@@ -154,20 +151,14 @@ type Manager interface {
 
 	DisableRouting() error
 
-	// AddDNATRule adds outbound DNAT rule for forwarding external traffic to the NetBird network.
+	// AddDNATRule adds a DNAT rule
 	AddDNATRule(ForwardRule) (Rule, error)
 
-	// DeleteDNATRule deletes the outbound DNAT rule.
+	// DeleteDNATRule deletes a DNAT rule
 	DeleteDNATRule(Rule) error
 
 	// UpdateSet updates the set with the given prefixes
 	UpdateSet(hash Set, prefixes []netip.Prefix) error
-
-	// AddInboundDNAT adds an inbound DNAT rule redirecting traffic from NetBird peers to local services
-	AddInboundDNAT(localAddr netip.Addr, protocol Protocol, sourcePort, targetPort uint16) error
-
-	// RemoveInboundDNAT removes inbound DNAT rule
-	RemoveInboundDNAT(localAddr netip.Addr, protocol Protocol, sourcePort, targetPort uint16) error
 }
 
 func GenKey(format string, pair RouterPair) string {

client/firewall/nftables/acl_linux.go

@@ -16,7 +16,7 @@ import (
 	"golang.org/x/sys/unix"
 
 	firewall "github.com/netbirdio/netbird/client/firewall/manager"
-	nbnet "github.com/netbirdio/netbird/client/net"
+	nbnet "github.com/netbirdio/netbird/util/net"
 )
 
 const (
@@ -29,6 +29,8 @@ const (
 	chainNameForwardFilter     = "netbird-acl-forward-filter"
 	chainNameManglePrerouting  = "netbird-mangle-prerouting"
 	chainNameManglePostrouting = "netbird-mangle-postrouting"
+
+	allowNetbirdInputRuleID = "allow Netbird incoming traffic"
 )
 
 const flushError = "flush: %w"
@@ -193,6 +195,25 @@ func (m *AclManager) DeletePeerRule(rule firewall.Rule) error {
 // createDefaultAllowRules creates default allow rules for the input and output chains
 func (m *AclManager) createDefaultAllowRules() error {
 	expIn := []expr.Any{
+		&expr.Payload{
+			DestRegister: 1,
+			Base:         expr.PayloadBaseNetworkHeader,
+			Offset:       12,
+			Len:          4,
+		},
+		// mask
+		&expr.Bitwise{
+			SourceRegister: 1,
+			DestRegister:   1,
+			Len:            4,
+			Mask:           []byte{0, 0, 0, 0},
+			Xor:            []byte{0, 0, 0, 0},
+		},
+		// net address
+		&expr.Cmp{
+			Register: 1,
+			Data:     []byte{0, 0, 0, 0},
+		},
 		&expr.Verdict{
 			Kind: expr.VerdictAccept,
 		},
@@ -237,7 +258,7 @@ func (m *AclManager) addIOFiltering(
 	action firewall.Action,
 	ipset *nftables.Set,
 ) (*Rule, error) {
-	ruleId := generatePeerRuleId(ip, proto, sPort, dPort, action, ipset)
+	ruleId := generatePeerRuleId(ip, sPort, dPort, action, ipset)
 	if r, ok := m.rules[ruleId]; ok {
 		return &Rule{
 			nftRule:    r.nftRule,
@@ -320,39 +341,30 @@ func (m *AclManager) addIOFiltering(
 	userData := []byte(ruleId)
 
 	chain := m.chainInputRules
-	rule := &nftables.Rule{
+	nftRule := m.rConn.AddRule(&nftables.Rule{
 		Table:    m.workTable,
 		Chain:    chain,
 		Exprs:    mainExpressions,
 		UserData: userData,
-	}
-
-	// Insert DROP rules at the beginning, append ACCEPT rules at the end
-	var nftRule *nftables.Rule
-	if action == firewall.ActionDrop {
-		nftRule = m.rConn.InsertRule(rule)
-	} else {
-		nftRule = m.rConn.AddRule(rule)
-	}
+	})
 
 	if err := m.rConn.Flush(); err != nil {
-		return nil, fmt.Errorf("flush input rule %s: %v", ruleId, err)
+		return nil, fmt.Errorf(flushError, err)
 	}
 
-	ruleStruct := &Rule{
-		nftRule: nftRule,
-		// best effort mangle rule
+	rule := &Rule{
+		nftRule:    nftRule,
 		mangleRule: m.createPreroutingRule(expressions, userData),
 		nftSet:     ipset,
 		ruleID:     ruleId,
 		ip:         ip,
 	}
-	m.rules[ruleId] = ruleStruct
+	m.rules[ruleId] = rule
 	if ipset != nil {
 		m.ipsetStore.AddReferenceToIpset(ipset.Name)
 	}
 
-	return ruleStruct, nil
+	return rule, nil
 }
 
 func (m *AclManager) createPreroutingRule(expressions []expr.Any, userData []byte) *nftables.Rule {
@@ -400,19 +412,12 @@ func (m *AclManager) createPreroutingRule(expressions []expr.Any, userData []byt
 		},
 	)
 
-	nfRule := m.rConn.AddRule(&nftables.Rule{
+	return m.rConn.AddRule(&nftables.Rule{
 		Table:    m.workTable,
 		Chain:    m.chainPrerouting,
 		Exprs:    preroutingExprs,
 		UserData: userData,
 	})
-
-	if err := m.rConn.Flush(); err != nil {
-		log.Errorf("failed to flush mangle rule %s: %v", string(userData), err)
-		return nil
-	}
-
-	return nfRule
 }
 
 func (m *AclManager) createDefaultChains() (err error) {
@@ -684,8 +689,8 @@ func (m *AclManager) refreshRuleHandles(chain *nftables.Chain, mangle bool) erro
 	return nil
 }
 
-func generatePeerRuleId(ip net.IP, proto firewall.Protocol, sPort *firewall.Port, dPort *firewall.Port, action firewall.Action, ipset *nftables.Set) string {
-	rulesetID := ":" + string(proto) + ":"
+func generatePeerRuleId(ip net.IP, sPort *firewall.Port, dPort *firewall.Port, action firewall.Action, ipset *nftables.Set) string {
+	rulesetID := ":"
 	if sPort != nil {
 		rulesetID += sPort.String()
 	}

client/firewall/nftables/manager_linux.go

@@ -1,11 +1,11 @@
 package nftables
 
 import (
+	"bytes"
 	"context"
 	"fmt"
 	"net"
 	"net/netip"
-	"os"
 	"sync"
 
 	"github.com/google/nftables"
@@ -19,22 +19,13 @@ import (
 )
 
 const (
-	// tableNameNetbird is the default name of the table that is used for filtering by the Netbird client
+	// tableNameNetbird is the name of the table that is used for filtering by the Netbird client
 	tableNameNetbird = "netbird"
-	// envTableName is the environment variable to override the table name
-	envTableName = "NB_NFTABLES_TABLE"
 
 	tableNameFilter = "filter"
 	chainNameInput  = "INPUT"
 )
 
-func getTableName() string {
-	if name := os.Getenv(envTableName); name != "" {
-		return name
-	}
-	return tableNameNetbird
-}
-
 // iFaceMapper defines subset methods of interface required for manager
 type iFaceMapper interface {
 	Name() string
@@ -53,16 +44,16 @@ type Manager struct {
 }
 
 // Create nftables firewall manager
-func Create(wgIface iFaceMapper, mtu uint16) (*Manager, error) {
+func Create(wgIface iFaceMapper) (*Manager, error) {
 	m := &Manager{
 		rConn:   &nftables.Conn{},
 		wgIface: wgIface,
 	}
 
-	workTable := &nftables.Table{Name: getTableName(), Family: nftables.TableFamilyIPv4}
+	workTable := &nftables.Table{Name: tableNameNetbird, Family: nftables.TableFamilyIPv4}
 
 	var err error
-	m.router, err = newRouter(workTable, wgIface, mtu)
+	m.router, err = newRouter(workTable, wgIface)
 	if err != nil {
 		return nil, fmt.Errorf("create router: %w", err)
 	}
@@ -102,7 +93,6 @@ func (m *Manager) Init(stateManager *statemanager.Manager) error {
 			NameStr:       m.wgIface.Name(),
 			WGAddress:     m.wgIface.Address(),
 			UserspaceBind: m.wgIface.IsUserspaceBind(),
-			MTU:           m.router.mtu,
 		},
 	}); err != nil {
 		log.Errorf("failed to update state: %v", err)
@@ -207,11 +197,44 @@ func (m *Manager) AllowNetbird() error {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
 
-	if err := m.aclManager.createDefaultAllowRules(); err != nil {
-		return fmt.Errorf("create default allow rules: %w", err)
+	err := m.aclManager.createDefaultAllowRules()
+	if err != nil {
+		return fmt.Errorf("failed to create default allow rules: %v", err)
 	}
-	if err := m.rConn.Flush(); err != nil {
-		return fmt.Errorf("flush allow input netbird rules: %w", err)
+
+	chains, err := m.rConn.ListChainsOfTableFamily(nftables.TableFamilyIPv4)
+	if err != nil {
+		return fmt.Errorf("list of chains: %w", err)
+	}
+
+	var chain *nftables.Chain
+	for _, c := range chains {
+		if c.Table.Name == tableNameFilter && c.Name == chainNameInput {
+			chain = c
+			break
+		}
+	}
+
+	if chain == nil {
+		log.Debugf("chain INPUT not found. Skipping add allow netbird rule")
+		return nil
+	}
+
+	rules, err := m.rConn.GetRules(chain.Table, chain)
+	if err != nil {
+		return fmt.Errorf("failed to get rules for the INPUT chain: %v", err)
+	}
+
+	if rule := m.detectAllowNetbirdRule(rules); rule != nil {
+		log.Debugf("allow netbird rule already exists: %v", rule)
+		return nil
+	}
+
+	m.applyAllowNetbirdRules(chain)
+
+	err = m.rConn.Flush()
+	if err != nil {
+		return fmt.Errorf("failed to flush allow input netbird rules: %v", err)
 	}
 
 	return nil
@@ -227,6 +250,10 @@ func (m *Manager) Close(stateManager *statemanager.Manager) error {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
 
+	if err := m.resetNetbirdInputRules(); err != nil {
+		return fmt.Errorf("reset netbird input rules: %v", err)
+	}
+
 	if err := m.router.Reset(); err != nil {
 		return fmt.Errorf("reset router: %v", err)
 	}
@@ -246,15 +273,49 @@ func (m *Manager) Close(stateManager *statemanager.Manager) error {
 	return nil
 }
 
+func (m *Manager) resetNetbirdInputRules() error {
+	chains, err := m.rConn.ListChains()
+	if err != nil {
+		return fmt.Errorf("list chains: %w", err)
+	}
+
+	m.deleteNetbirdInputRules(chains)
+
+	return nil
+}
+
+func (m *Manager) deleteNetbirdInputRules(chains []*nftables.Chain) {
+	for _, c := range chains {
+		if c.Table.Name == tableNameFilter && c.Name == chainNameInput {
+			rules, err := m.rConn.GetRules(c.Table, c)
+			if err != nil {
+				log.Errorf("get rules for chain %q: %v", c.Name, err)
+				continue
+			}
+
+			m.deleteMatchingRules(rules)
+		}
+	}
+}
+
+func (m *Manager) deleteMatchingRules(rules []*nftables.Rule) {
+	for _, r := range rules {
+		if bytes.Equal(r.UserData, []byte(allowNetbirdInputRuleID)) {
+			if err := m.rConn.DelRule(r); err != nil {
+				log.Errorf("delete rule: %v", err)
+			}
+		}
+	}
+}
+
 func (m *Manager) cleanupNetbirdTables() error {
 	tables, err := m.rConn.ListTables()
 	if err != nil {
 		return fmt.Errorf("list tables: %w", err)
 	}
 
-	tableName := getTableName()
 	for _, t := range tables {
-		if t.Name == tableName {
+		if t.Name == tableNameNetbird {
 			m.rConn.DelTable(t)
 		}
 	}
@@ -315,40 +376,61 @@ func (m *Manager) UpdateSet(set firewall.Set, prefixes []netip.Prefix) error {
 	return m.router.UpdateSet(set, prefixes)
 }
 
-// AddInboundDNAT adds an inbound DNAT rule redirecting traffic from NetBird peers to local services.
-func (m *Manager) AddInboundDNAT(localAddr netip.Addr, protocol firewall.Protocol, sourcePort, targetPort uint16) error {
-	m.mutex.Lock()
-	defer m.mutex.Unlock()
-
-	return m.router.AddInboundDNAT(localAddr, protocol, sourcePort, targetPort)
-}
-
-// RemoveInboundDNAT removes an inbound DNAT rule.
-func (m *Manager) RemoveInboundDNAT(localAddr netip.Addr, protocol firewall.Protocol, sourcePort, targetPort uint16) error {
-	m.mutex.Lock()
-	defer m.mutex.Unlock()
-
-	return m.router.RemoveInboundDNAT(localAddr, protocol, sourcePort, targetPort)
-}
-
 func (m *Manager) createWorkTable() (*nftables.Table, error) {
 	tables, err := m.rConn.ListTablesOfFamily(nftables.TableFamilyIPv4)
 	if err != nil {
 		return nil, fmt.Errorf("list of tables: %w", err)
 	}
 
-	tableName := getTableName()
 	for _, t := range tables {
-		if t.Name == tableName {
+		if t.Name == tableNameNetbird {
 			m.rConn.DelTable(t)
 		}
 	}
 
-	table := m.rConn.AddTable(&nftables.Table{Name: getTableName(), Family: nftables.TableFamilyIPv4})
+	table := m.rConn.AddTable(&nftables.Table{Name: tableNameNetbird, Family: nftables.TableFamilyIPv4})
 	err = m.rConn.Flush()
 	return table, err
 }
 
+func (m *Manager) applyAllowNetbirdRules(chain *nftables.Chain) {
+	rule := &nftables.Rule{
+		Table: chain.Table,
+		Chain: chain,
+		Exprs: []expr.Any{
+			&expr.Meta{Key: expr.MetaKeyIIFNAME, Register: 1},
+			&expr.Cmp{
+				Op:       expr.CmpOpEq,
+				Register: 1,
+				Data:     ifname(m.wgIface.Name()),
+			},
+			&expr.Verdict{
+				Kind: expr.VerdictAccept,
+			},
+		},
+		UserData: []byte(allowNetbirdInputRuleID),
+	}
+	_ = m.rConn.InsertRule(rule)
+}
+
+func (m *Manager) detectAllowNetbirdRule(existedRules []*nftables.Rule) *nftables.Rule {
+	ifName := ifname(m.wgIface.Name())
+	for _, rule := range existedRules {
+		if rule.Table.Name == tableNameFilter && rule.Chain.Name == chainNameInput {
+			if len(rule.Exprs) < 4 {
+				if e, ok := rule.Exprs[0].(*expr.Meta); !ok || e.Key != expr.MetaKeyIIFNAME {
+					continue
+				}
+				if e, ok := rule.Exprs[1].(*expr.Cmp); !ok || e.Op != expr.CmpOpEq || !bytes.Equal(e.Data, ifName) {
+					continue
+				}
+				return rule
+			}
+		}
+	}
+	return nil
+}
+
 func insertReturnTrafficRule(conn *nftables.Conn, table *nftables.Table, chain *nftables.Chain) {
 	rule := &nftables.Rule{
 		Table: table,

client/firewall/nftables/manager_linux_test.go

@@ -2,7 +2,6 @@ package nftables
 
 import (
 	"bytes"
-	"encoding/binary"
 	"fmt"
 	"net/netip"
 	"os/exec"
@@ -16,13 +15,12 @@ import (
 	"golang.org/x/sys/unix"
 
 	fw "github.com/netbirdio/netbird/client/firewall/manager"
-	"github.com/netbirdio/netbird/client/iface"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
 )
 
 var ifaceMock = &iFaceMock{
 	NameFunc: func() string {
-		return "wg-test"
+		return "lo"
 	},
 	AddressFunc: func() wgaddr.Address {
 		return wgaddr.Address{
@@ -57,7 +55,7 @@ func (i *iFaceMock) IsUserspaceBind() bool { return false }
 func TestNftablesManager(t *testing.T) {
 
 	// just check on the local interface
-	manager, err := Create(ifaceMock, iface.DefaultMTU)
+	manager, err := Create(ifaceMock)
 	require.NoError(t, err)
 	require.NoError(t, manager.Init(nil))
 	time.Sleep(time.Second * 3)
@@ -105,8 +103,9 @@ func TestNftablesManager(t *testing.T) {
 			Kind: expr.VerdictAccept,
 		},
 	}
-	// Since DROP rules are inserted at position 0, the DROP rule comes first
-	expectedDropExprs := []expr.Any{
+	compareExprsIgnoringCounters(t, rules[0].Exprs, expectedExprs1)
+
+	expectedExprs2 := []expr.Any{
 		&expr.Payload{
 			DestRegister: 1,
 			Base:         expr.PayloadBaseNetworkHeader,
@@ -142,12 +141,7 @@ func TestNftablesManager(t *testing.T) {
 		},
 		&expr.Verdict{Kind: expr.VerdictDrop},
 	}
-
-	// Compare DROP rule at position 0 (inserted first due to InsertRule)
-	compareExprsIgnoringCounters(t, rules[0].Exprs, expectedDropExprs)
-
-	// Compare connection tracking rule at position 1 (pushed down by DROP rule insertion)
-	compareExprsIgnoringCounters(t, rules[1].Exprs, expectedExprs1)
+	require.ElementsMatch(t, rules[1].Exprs, expectedExprs2, "expected the same expressions")
 
 	for _, r := range rule {
 		err = manager.DeletePeerRule(r)
@@ -166,90 +160,10 @@ func TestNftablesManager(t *testing.T) {
 	require.NoError(t, err, "failed to reset")
 }
 
-func TestNftablesManagerRuleOrder(t *testing.T) {
-	// This test verifies rule insertion order in nftables peer ACLs
-	// We add accept rule first, then deny rule to test ordering behavior
-	manager, err := Create(ifaceMock, iface.DefaultMTU)
-	require.NoError(t, err)
-	require.NoError(t, manager.Init(nil))
-
-	defer func() {
-		err = manager.Close(nil)
-		require.NoError(t, err)
-	}()
-
-	ip := netip.MustParseAddr("100.96.0.2").Unmap()
-	testClient := &nftables.Conn{}
-
-	// Add accept rule first
-	_, err = manager.AddPeerFiltering(nil, ip.AsSlice(), fw.ProtocolTCP, nil, &fw.Port{Values: []uint16{80}}, fw.ActionAccept, "accept-http")
-	require.NoError(t, err, "failed to add accept rule")
-
-	// Add deny rule second for the same traffic
-	_, err = manager.AddPeerFiltering(nil, ip.AsSlice(), fw.ProtocolTCP, nil, &fw.Port{Values: []uint16{80}}, fw.ActionDrop, "deny-http")
-	require.NoError(t, err, "failed to add deny rule")
-
-	err = manager.Flush()
-	require.NoError(t, err, "failed to flush")
-
-	rules, err := testClient.GetRules(manager.aclManager.workTable, manager.aclManager.chainInputRules)
-	require.NoError(t, err, "failed to get rules")
-
-	t.Logf("Found %d rules in nftables chain", len(rules))
-
-	// Find the accept and deny rules and verify deny comes before accept
-	var acceptRuleIndex, denyRuleIndex int = -1, -1
-	for i, rule := range rules {
-		hasAcceptHTTPSet := false
-		hasDenyHTTPSet := false
-		hasPort80 := false
-		var action string
-
-		for _, e := range rule.Exprs {
-			// Check for set lookup
-			if lookup, ok := e.(*expr.Lookup); ok {
-				if lookup.SetName == "accept-http" {
-					hasAcceptHTTPSet = true
-				} else if lookup.SetName == "deny-http" {
-					hasDenyHTTPSet = true
-				}
-			}
-			// Check for port 80
-			if cmp, ok := e.(*expr.Cmp); ok {
-				if cmp.Op == expr.CmpOpEq && len(cmp.Data) == 2 && binary.BigEndian.Uint16(cmp.Data) == 80 {
-					hasPort80 = true
-				}
-			}
-			// Check for verdict
-			if verdict, ok := e.(*expr.Verdict); ok {
-				if verdict.Kind == expr.VerdictAccept {
-					action = "ACCEPT"
-				} else if verdict.Kind == expr.VerdictDrop {
-					action = "DROP"
-				}
-			}
-		}
-
-		if hasAcceptHTTPSet && hasPort80 && action == "ACCEPT" {
-			t.Logf("Rule [%d]: accept-http set + Port 80 + ACCEPT", i)
-			acceptRuleIndex = i
-		} else if hasDenyHTTPSet && hasPort80 && action == "DROP" {
-			t.Logf("Rule [%d]: deny-http set + Port 80 + DROP", i)
-			denyRuleIndex = i
-		}
-	}
-
-	require.NotEqual(t, -1, acceptRuleIndex, "accept rule should exist in nftables")
-	require.NotEqual(t, -1, denyRuleIndex, "deny rule should exist in nftables")
-	require.Less(t, denyRuleIndex, acceptRuleIndex,
-		"deny rule should come before accept rule in nftables chain (deny at index %d, accept at index %d)",
-		denyRuleIndex, acceptRuleIndex)
-}
-
 func TestNFtablesCreatePerformance(t *testing.T) {
 	mock := &iFaceMock{
 		NameFunc: func() string {
-			return "wg-test"
+			return "lo"
 		},
 		AddressFunc: func() wgaddr.Address {
 			return wgaddr.Address{
@@ -262,7 +176,7 @@ func TestNFtablesCreatePerformance(t *testing.T) {
 	for _, testMax := range []int{10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000} {
 		t.Run(fmt.Sprintf("Testing %d rules", testMax), func(t *testing.T) {
 			// just check on the local interface
-			manager, err := Create(mock, iface.DefaultMTU)
+			manager, err := Create(mock)
 			require.NoError(t, err)
 			require.NoError(t, manager.Init(nil))
 			time.Sleep(time.Second * 3)
@@ -346,7 +260,7 @@ func TestNftablesManagerCompatibilityWithIptables(t *testing.T) {
 	stdout, stderr := runIptablesSave(t)
 	verifyIptablesOutput(t, stdout, stderr)
 
-	manager, err := Create(ifaceMock, iface.DefaultMTU)
+	manager, err := Create(ifaceMock)
 	require.NoError(t, err, "failed to create manager")
 	require.NoError(t, manager.Init(nil))
 

client/firewall/nftables/router_linux.go

@@ -16,14 +16,13 @@ import (
 	"github.com/google/nftables/xt"
 	"github.com/hashicorp/go-multierror"
 	log "github.com/sirupsen/logrus"
-	"golang.org/x/sys/unix"
 
 	nberrors "github.com/netbirdio/netbird/client/errors"
 	firewall "github.com/netbirdio/netbird/client/firewall/manager"
 	nbid "github.com/netbirdio/netbird/client/internal/acl/id"
 	"github.com/netbirdio/netbird/client/internal/routemanager/ipfwdstate"
 	"github.com/netbirdio/netbird/client/internal/routemanager/refcounter"
-	nbnet "github.com/netbirdio/netbird/client/net"
+	nbnet "github.com/netbirdio/netbird/util/net"
 )
 
 const (
@@ -33,17 +32,12 @@ const (
 	chainNameRoutingNat    = "netbird-rt-postrouting"
 	chainNameRoutingRdr    = "netbird-rt-redirect"
 	chainNameForward       = "FORWARD"
-	chainNameMangleForward = "netbird-mangle-forward"
 
 	userDataAcceptForwardRuleIif = "frwacceptiif"
 	userDataAcceptForwardRuleOif = "frwacceptoif"
-	userDataAcceptInputRule      = "inputaccept"
 
 	dnatSuffix = "_dnat"
 	snatSuffix = "_snat"
-
-	// ipTCPHeaderMinSize represents minimum IP (20) + TCP (20) header size for MSS calculation
-	ipTCPHeaderMinSize = 40
 )
 
 const refreshRulesMapError = "refresh rules map: %w"
@@ -69,10 +63,9 @@ type router struct {
 	wgIface          iFaceMapper
 	ipFwdState       *ipfwdstate.IPForwardingState
 	legacyManagement bool
-	mtu              uint16
 }
 
-func newRouter(workTable *nftables.Table, wgIface iFaceMapper, mtu uint16) (*router, error) {
+func newRouter(workTable *nftables.Table, wgIface iFaceMapper) (*router, error) {
 	r := &router{
 		conn:       &nftables.Conn{},
 		workTable:  workTable,
@@ -80,7 +73,6 @@ func newRouter(workTable *nftables.Table, wgIface iFaceMapper, mtu uint16) (*rou
 		rules:      make(map[string]*nftables.Rule),
 		wgIface:    wgIface,
 		ipFwdState: ipfwdstate.NewIPForwardingState(),
-		mtu:        mtu,
 	}
 
 	r.ipsetCounter = refcounter.New(
@@ -104,8 +96,8 @@ func newRouter(workTable *nftables.Table, wgIface iFaceMapper, mtu uint16) (*rou
 func (r *router) init(workTable *nftables.Table) error {
 	r.workTable = workTable
 
-	if err := r.removeAcceptFilterRules(); err != nil {
-		log.Errorf("failed to clean up rules from filter table: %s", err)
+	if err := r.removeAcceptForwardRules(); err != nil {
+		log.Errorf("failed to clean up rules from FORWARD chain: %s", err)
 	}
 
 	if err := r.createContainers(); err != nil {
@@ -119,15 +111,15 @@ func (r *router) init(workTable *nftables.Table) error {
 	return nil
 }
 
-// Reset cleans existing nftables filter table rules from the system
+// Reset cleans existing nftables default forward rules from the system
 func (r *router) Reset() error {
 	// clear without deleting the ipsets, the nf table will be deleted by the caller
 	r.ipsetCounter.Clear()
 
 	var merr *multierror.Error
 
-	if err := r.removeAcceptFilterRules(); err != nil {
-		merr = multierror.Append(merr, fmt.Errorf("remove accept filter rules: %w", err))
+	if err := r.removeAcceptForwardRules(); err != nil {
+		merr = multierror.Append(merr, fmt.Errorf("remove accept forward rules: %w", err))
 	}
 
 	if err := r.removeNatPreroutingRules(); err != nil {
@@ -228,23 +220,11 @@ func (r *router) createContainers() error {
 		Type:     nftables.ChainTypeFilter,
 	})
 
-	r.chains[chainNameMangleForward] = r.conn.AddChain(&nftables.Chain{
-		Name:     chainNameMangleForward,
-		Table:    r.workTable,
-		Hooknum:  nftables.ChainHookForward,
-		Priority: nftables.ChainPriorityMangle,
-		Type:     nftables.ChainTypeFilter,
-	})
-
 	// Add the single NAT rule that matches on mark
 	if err := r.addPostroutingRules(); err != nil {
 		return fmt.Errorf("add single nat rule: %v", err)
 	}
 
-	if err := r.addMSSClampingRules(); err != nil {
-		log.Errorf("failed to add MSS clamping rules: %s", err)
-	}
-
 	if err := r.acceptForwardRules(); err != nil {
 		log.Errorf("failed to add accept rules for the forward chain: %s", err)
 	}
@@ -765,83 +745,6 @@ func (r *router) addPostroutingRules() error {
 	return nil
 }
 
-// addMSSClampingRules adds MSS clamping rules to prevent fragmentation for forwarded traffic.
-// TODO: Add IPv6 support
-func (r *router) addMSSClampingRules() error {
-	mss := r.mtu - ipTCPHeaderMinSize
-
-	exprsOut := []expr.Any{
-		&expr.Meta{
-			Key:      expr.MetaKeyOIFNAME,
-			Register: 1,
-		},
-		&expr.Cmp{
-			Op:       expr.CmpOpEq,
-			Register: 1,
-			Data:     ifname(r.wgIface.Name()),
-		},
-		&expr.Meta{
-			Key:      expr.MetaKeyL4PROTO,
-			Register: 1,
-		},
-		&expr.Cmp{
-			Op:       expr.CmpOpEq,
-			Register: 1,
-			Data:     []byte{unix.IPPROTO_TCP},
-		},
-		&expr.Payload{
-			DestRegister: 1,
-			Base:         expr.PayloadBaseTransportHeader,
-			Offset:       13,
-			Len:          1,
-		},
-		&expr.Bitwise{
-			DestRegister:   1,
-			SourceRegister: 1,
-			Len:            1,
-			Mask:           []byte{0x02},
-			Xor:            []byte{0x00},
-		},
-		&expr.Cmp{
-			Op:       expr.CmpOpNeq,
-			Register: 1,
-			Data:     []byte{0x00},
-		},
-		&expr.Counter{},
-		&expr.Exthdr{
-			DestRegister: 1,
-			Type:         2,
-			Offset:       2,
-			Len:          2,
-			Op:           expr.ExthdrOpTcpopt,
-		},
-		&expr.Cmp{
-			Op:       expr.CmpOpGt,
-			Register: 1,
-			Data:     binaryutil.BigEndian.PutUint16(uint16(mss)),
-		},
-		&expr.Immediate{
-			Register: 1,
-			Data:     binaryutil.BigEndian.PutUint16(uint16(mss)),
-		},
-		&expr.Exthdr{
-			SourceRegister: 1,
-			Type:           2,
-			Offset:         2,
-			Len:            2,
-			Op:             expr.ExthdrOpTcpopt,
-		},
-	}
-
-	r.conn.AddRule(&nftables.Rule{
-		Table: r.workTable,
-		Chain: r.chains[chainNameMangleForward],
-		Exprs: exprsOut,
-	})
-
-	return nil
-}
-
 // addLegacyRouteRule adds a legacy routing rule for mgmt servers pre route acls
 func (r *router) addLegacyRouteRule(pair firewall.RouterPair) error {
 	sourceExp, err := r.applyNetwork(pair.Source, nil, true)
@@ -937,7 +840,6 @@ func (r *router) RemoveAllLegacyRouteRules() error {
 // that our traffic is not dropped by existing rules there.
 // The existing FORWARD rules/policies decide outbound traffic towards our interface.
 // In case the FORWARD policy is set to "drop", we add an established/related rule to allow return traffic for the inbound rule.
-// This method also adds INPUT chain rules to allow traffic to the local interface.
 func (r *router) acceptForwardRules() error {
 	if r.filterTable == nil {
 		log.Debugf("table 'filter' not found for forward rules, skipping accept rules")
@@ -947,7 +849,7 @@ func (r *router) acceptForwardRules() error {
 	fw := "iptables"
 
 	defer func() {
-		log.Debugf("Used %s to add accept forward and input rules", fw)
+		log.Debugf("Used %s to add accept forward rules", fw)
 	}()
 
 	// Try iptables first and fallback to nftables if iptables is not available
@@ -957,30 +859,22 @@ func (r *router) acceptForwardRules() error {
 		log.Warnf("Will use nftables to manipulate the filter table because iptables is not available: %v", err)
 
 		fw = "nftables"
-		return r.acceptFilterRulesNftables()
+		return r.acceptForwardRulesNftables()
 	}
 
-	return r.acceptFilterRulesIptables(ipt)
+	return r.acceptForwardRulesIptables(ipt)
 }
 
-func (r *router) acceptFilterRulesIptables(ipt *iptables.IPTables) error {
+func (r *router) acceptForwardRulesIptables(ipt *iptables.IPTables) error {
 	var merr *multierror.Error
-
 	for _, rule := range r.getAcceptForwardRules() {
 		if err := ipt.Insert("filter", chainNameForward, 1, rule...); err != nil {
-			merr = multierror.Append(err, fmt.Errorf("add iptables forward rule: %v", err))
+			merr = multierror.Append(err, fmt.Errorf("add iptables rule: %v", err))
 		} else {
-			log.Debugf("added iptables forward rule: %v", rule)
+			log.Debugf("added iptables rule: %v", rule)
 		}
 	}
 
-	inputRule := r.getAcceptInputRule()
-	if err := ipt.Insert("filter", chainNameInput, 1, inputRule...); err != nil {
-		merr = multierror.Append(err, fmt.Errorf("add iptables input rule: %v", err))
-	} else {
-		log.Debugf("added iptables input rule: %v", inputRule)
-	}
-
 	return nberrors.FormatErrorOrNil(merr)
 }
 
@@ -992,13 +886,10 @@ func (r *router) getAcceptForwardRules() [][]string {
 	}
 }
 
-func (r *router) getAcceptInputRule() []string {
-	return []string{"-i", r.wgIface.Name(), "-j", "ACCEPT"}
-}
-
-func (r *router) acceptFilterRulesNftables() error {
+func (r *router) acceptForwardRulesNftables() error {
 	intf := ifname(r.wgIface.Name())
 
+	// Rule for incoming interface (iif) with counter
 	iifRule := &nftables.Rule{
 		Table: r.filterTable,
 		Chain: &nftables.Chain{
@@ -1031,10 +922,11 @@ func (r *router) acceptFilterRulesNftables() error {
 		},
 	}
 
+	// Rule for outgoing interface (oif) with counter
 	oifRule := &nftables.Rule{
 		Table: r.filterTable,
 		Chain: &nftables.Chain{
-			Name:     chainNameForward,
+			Name:     "FORWARD",
 			Table:    r.filterTable,
 			Type:     nftables.ChainTypeFilter,
 			Hooknum:  nftables.ChainHookForward,
@@ -1043,60 +935,35 @@ func (r *router) acceptFilterRulesNftables() error {
 		Exprs:    append(oifExprs, getEstablishedExprs(2)...),
 		UserData: []byte(userDataAcceptForwardRuleOif),
 	}
-	r.conn.InsertRule(oifRule)
 
-	inputRule := &nftables.Rule{
-		Table: r.filterTable,
-		Chain: &nftables.Chain{
-			Name:     chainNameInput,
-			Table:    r.filterTable,
-			Type:     nftables.ChainTypeFilter,
-			Hooknum:  nftables.ChainHookInput,
-			Priority: nftables.ChainPriorityFilter,
-		},
-		Exprs: []expr.Any{
-			&expr.Meta{Key: expr.MetaKeyIIFNAME, Register: 1},
-			&expr.Cmp{
-				Op:       expr.CmpOpEq,
-				Register: 1,
-				Data:     intf,
-			},
-			&expr.Counter{},
-			&expr.Verdict{Kind: expr.VerdictAccept},
-		},
-		UserData: []byte(userDataAcceptInputRule),
-	}
-	r.conn.InsertRule(inputRule)
+	r.conn.InsertRule(oifRule)
 
 	return nil
 }
 
-func (r *router) removeAcceptFilterRules() error {
+func (r *router) removeAcceptForwardRules() error {
 	if r.filterTable == nil {
 		return nil
 	}
 
+	// Try iptables first and fallback to nftables if iptables is not available
 	ipt, err := iptables.New()
 	if err != nil {
 		log.Warnf("Will use nftables to manipulate the filter table because iptables is not available: %v", err)
-		return r.removeAcceptFilterRulesNftables()
+		return r.removeAcceptForwardRulesNftables()
 	}
 
-	return r.removeAcceptFilterRulesIptables(ipt)
+	return r.removeAcceptForwardRulesIptables(ipt)
 }
 
-func (r *router) removeAcceptFilterRulesNftables() error {
+func (r *router) removeAcceptForwardRulesNftables() error {
 	chains, err := r.conn.ListChainsOfTableFamily(nftables.TableFamilyIPv4)
 	if err != nil {
 		return fmt.Errorf("list chains: %v", err)
 	}
 
 	for _, chain := range chains {
-		if chain.Table.Name != r.filterTable.Name {
-			continue
-		}
-
-		if chain.Name != chainNameForward && chain.Name != chainNameInput {
+		if chain.Table.Name != r.filterTable.Name || chain.Name != chainNameForward {
 			continue
 		}
 
@@ -1107,8 +974,7 @@ func (r *router) removeAcceptFilterRulesNftables() error {
 
 		for _, rule := range rules {
 			if bytes.Equal(rule.UserData, []byte(userDataAcceptForwardRuleIif)) ||
-				bytes.Equal(rule.UserData, []byte(userDataAcceptForwardRuleOif)) ||
-				bytes.Equal(rule.UserData, []byte(userDataAcceptInputRule)) {
+				bytes.Equal(rule.UserData, []byte(userDataAcceptForwardRuleOif)) {
 				if err := r.conn.DelRule(rule); err != nil {
 					return fmt.Errorf("delete rule: %v", err)
 				}
@@ -1123,20 +989,14 @@ func (r *router) removeAcceptFilterRulesNftables() error {
 	return nil
 }
 
-func (r *router) removeAcceptFilterRulesIptables(ipt *iptables.IPTables) error {
+func (r *router) removeAcceptForwardRulesIptables(ipt *iptables.IPTables) error {
 	var merr *multierror.Error
-
 	for _, rule := range r.getAcceptForwardRules() {
 		if err := ipt.DeleteIfExists("filter", chainNameForward, rule...); err != nil {
-			merr = multierror.Append(err, fmt.Errorf("remove iptables forward rule: %v", err))
+			merr = multierror.Append(err, fmt.Errorf("remove iptables rule: %v", err))
 		}
 	}
 
-	inputRule := r.getAcceptInputRule()
-	if err := ipt.DeleteIfExists("filter", chainNameInput, inputRule...); err != nil {
-		merr = multierror.Append(err, fmt.Errorf("remove iptables input rule: %v", err))
-	}
-
 	return nberrors.FormatErrorOrNil(merr)
 }
 
@@ -1490,103 +1350,6 @@ func (r *router) UpdateSet(set firewall.Set, prefixes []netip.Prefix) error {
 	return nil
 }
 
-// AddInboundDNAT adds an inbound DNAT rule redirecting traffic from NetBird peers to local services.
-func (r *router) AddInboundDNAT(localAddr netip.Addr, protocol firewall.Protocol, sourcePort, targetPort uint16) error {
-	ruleID := fmt.Sprintf("inbound-dnat-%s-%s-%d-%d", localAddr.String(), protocol, sourcePort, targetPort)
-
-	if _, exists := r.rules[ruleID]; exists {
-		return nil
-	}
-
-	protoNum, err := protoToInt(protocol)
-	if err != nil {
-		return fmt.Errorf("convert protocol to number: %w", err)
-	}
-
-	exprs := []expr.Any{
-		&expr.Meta{Key: expr.MetaKeyIIFNAME, Register: 1},
-		&expr.Cmp{
-			Op:       expr.CmpOpEq,
-			Register: 1,
-			Data:     ifname(r.wgIface.Name()),
-		},
-		&expr.Meta{Key: expr.MetaKeyL4PROTO, Register: 2},
-		&expr.Cmp{
-			Op:       expr.CmpOpEq,
-			Register: 2,
-			Data:     []byte{protoNum},
-		},
-		&expr.Payload{
-			DestRegister: 3,
-			Base:         expr.PayloadBaseTransportHeader,
-			Offset:       2,
-			Len:          2,
-		},
-		&expr.Cmp{
-			Op:       expr.CmpOpEq,
-			Register: 3,
-			Data:     binaryutil.BigEndian.PutUint16(sourcePort),
-		},
-	}
-
-	exprs = append(exprs, applyPrefix(netip.PrefixFrom(localAddr, 32), false)...)
-
-	exprs = append(exprs,
-		&expr.Immediate{
-			Register: 1,
-			Data:     localAddr.AsSlice(),
-		},
-		&expr.Immediate{
-			Register: 2,
-			Data:     binaryutil.BigEndian.PutUint16(targetPort),
-		},
-		&expr.NAT{
-			Type:        expr.NATTypeDestNAT,
-			Family:      uint32(nftables.TableFamilyIPv4),
-			RegAddrMin:  1,
-			RegProtoMin: 2,
-			RegProtoMax: 0,
-		},
-	)
-
-	dnatRule := &nftables.Rule{
-		Table:    r.workTable,
-		Chain:    r.chains[chainNameRoutingRdr],
-		Exprs:    exprs,
-		UserData: []byte(ruleID),
-	}
-	r.conn.AddRule(dnatRule)
-
-	if err := r.conn.Flush(); err != nil {
-		return fmt.Errorf("add inbound DNAT rule: %w", err)
-	}
-
-	r.rules[ruleID] = dnatRule
-
-	return nil
-}
-
-// RemoveInboundDNAT removes an inbound DNAT rule.
-func (r *router) RemoveInboundDNAT(localAddr netip.Addr, protocol firewall.Protocol, sourcePort, targetPort uint16) error {
-	if err := r.refreshRulesMap(); err != nil {
-		return fmt.Errorf(refreshRulesMapError, err)
-	}
-
-	ruleID := fmt.Sprintf("inbound-dnat-%s-%s-%d-%d", localAddr.String(), protocol, sourcePort, targetPort)
-
-	if rule, exists := r.rules[ruleID]; exists {
-		if err := r.conn.DelRule(rule); err != nil {
-			return fmt.Errorf("delete inbound DNAT rule %s: %w", ruleID, err)
-		}
-		if err := r.conn.Flush(); err != nil {
-			return fmt.Errorf("flush delete inbound DNAT rule: %w", err)
-		}
-		delete(r.rules, ruleID)
-	}
-
-	return nil
-}
-
 // applyNetwork generates nftables expressions for networks (CIDR) or sets
 func (r *router) applyNetwork(
 	network firewall.Network,

client/firewall/nftables/router_linux_test.go

@@ -17,7 +17,6 @@ import (
 
 	firewall "github.com/netbirdio/netbird/client/firewall/manager"
 	"github.com/netbirdio/netbird/client/firewall/test"
-	"github.com/netbirdio/netbird/client/iface"
 )
 
 const (
@@ -37,7 +36,7 @@ func TestNftablesManager_AddNatRule(t *testing.T) {
 	for _, testCase := range test.InsertRuleTestCases {
 		t.Run(testCase.Name, func(t *testing.T) {
 			// need fw manager to init both acl mgr and router for all chains to be present
-			manager, err := Create(ifaceMock, iface.DefaultMTU)
+			manager, err := Create(ifaceMock)
 			t.Cleanup(func() {
 				require.NoError(t, manager.Close(nil))
 			})
@@ -126,7 +125,7 @@ func TestNftablesManager_RemoveNatRule(t *testing.T) {
 
 	for _, testCase := range test.RemoveRuleTestCases {
 		t.Run(testCase.Name, func(t *testing.T) {
-			manager, err := Create(ifaceMock, iface.DefaultMTU)
+			manager, err := Create(ifaceMock)
 			t.Cleanup(func() {
 				require.NoError(t, manager.Close(nil))
 			})
@@ -198,7 +197,7 @@ func TestRouter_AddRouteFiltering(t *testing.T) {
 
 	defer deleteWorkTable()
 
-	r, err := newRouter(workTable, ifaceMock, iface.DefaultMTU)
+	r, err := newRouter(workTable, ifaceMock)
 	require.NoError(t, err, "Failed to create router")
 	require.NoError(t, r.init(workTable))
 
@@ -365,7 +364,7 @@ func TestNftablesCreateIpSet(t *testing.T) {
 
 	defer deleteWorkTable()
 
-	r, err := newRouter(workTable, ifaceMock, iface.DefaultMTU)
+	r, err := newRouter(workTable, ifaceMock)
 	require.NoError(t, err, "Failed to create router")
 	require.NoError(t, r.init(workTable))
 

client/firewall/nftables/state_linux.go

@@ -3,7 +3,6 @@ package nftables
 import (
 	"fmt"
 
-	"github.com/netbirdio/netbird/client/iface"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
 )
 
@@ -11,7 +10,6 @@ type InterfaceState struct {
 	NameStr       string         `json:"name"`
 	WGAddress     wgaddr.Address `json:"wg_address"`
 	UserspaceBind bool           `json:"userspace_bind"`
-	MTU           uint16         `json:"mtu"`
 }
 
 func (i *InterfaceState) Name() string {
@@ -35,11 +33,7 @@ func (s *ShutdownState) Name() string {
 }
 
 func (s *ShutdownState) Cleanup() error {
-	mtu := s.InterfaceState.MTU
-	if mtu == 0 {
-		mtu = iface.DefaultMTU
-	}
-	nft, err := Create(s.InterfaceState, mtu)
+	nft, err := Create(s.InterfaceState)
 	if err != nil {
 		return fmt.Errorf("create nftables manager: %w", err)
 	}

client/firewall/uspfilter/allow_netbird.go

@@ -18,7 +18,6 @@ func (m *Manager) Close(stateManager *statemanager.Manager) error {
 	defer m.mutex.Unlock()
 
 	m.outgoingRules = make(map[netip.Addr]RuleSet)
-	m.incomingDenyRules = make(map[netip.Addr]RuleSet)
 	m.incomingRules = make(map[netip.Addr]RuleSet)
 
 	if m.udpTracker != nil {

client/firewall/uspfilter/allow_netbird_windows.go

@@ -27,7 +27,6 @@ func (m *Manager) Close(*statemanager.Manager) error {
 	defer m.mutex.Unlock()
 
 	m.outgoingRules = make(map[netip.Addr]RuleSet)
-	m.incomingDenyRules = make(map[netip.Addr]RuleSet)
 	m.incomingRules = make(map[netip.Addr]RuleSet)
 
 	if m.udpTracker != nil {

client/firewall/uspfilter/conntrack/common.go

@@ -22,8 +22,6 @@ type BaseConnTrack struct {
 	PacketsRx atomic.Uint64
 	BytesTx   atomic.Uint64
 	BytesRx   atomic.Uint64
-
-	DNATOrigPort atomic.Uint32
 }
 
 // these small methods will be inlined by the compiler

client/firewall/uspfilter/conntrack/tcp.go

@@ -157,7 +157,7 @@ func NewTCPTracker(timeout time.Duration, logger *nblog.Logger, flowLogger nftyp
 	return tracker
 }
 
-func (t *TCPTracker) updateIfExists(srcIP, dstIP netip.Addr, srcPort, dstPort uint16, flags uint8, direction nftypes.Direction, size int) (ConnKey, uint16, bool) {
+func (t *TCPTracker) updateIfExists(srcIP, dstIP netip.Addr, srcPort, dstPort uint16, flags uint8, direction nftypes.Direction, size int) (ConnKey, bool) {
 	key := ConnKey{
 		SrcIP:   srcIP,
 		DstIP:   dstIP,
@@ -171,30 +171,28 @@ func (t *TCPTracker) updateIfExists(srcIP, dstIP netip.Addr, srcPort, dstPort ui
 
 	if exists {
 		t.updateState(key, conn, flags, direction, size)
-		return key, uint16(conn.DNATOrigPort.Load()), true
+		return key, true
 	}
 
-	return key, 0, false
+	return key, false
 }
 
-// TrackOutbound records an outbound TCP connection and returns the original port if DNAT reversal is needed
-func (t *TCPTracker) TrackOutbound(srcIP, dstIP netip.Addr, srcPort, dstPort uint16, flags uint8, size int) uint16 {
-	if _, origPort, exists := t.updateIfExists(dstIP, srcIP, dstPort, srcPort, flags, nftypes.Egress, size); exists {
-		return origPort
+// TrackOutbound records an outbound TCP connection
+func (t *TCPTracker) TrackOutbound(srcIP, dstIP netip.Addr, srcPort, dstPort uint16, flags uint8, size int) {
+	if _, exists := t.updateIfExists(dstIP, srcIP, dstPort, srcPort, flags, nftypes.Egress, size); !exists {
+		// if (inverted direction) conn is not tracked, track this direction
+		t.track(srcIP, dstIP, srcPort, dstPort, flags, nftypes.Egress, nil, size)
 	}
-	// if (inverted direction) conn is not tracked, track this direction
-	t.track(srcIP, dstIP, srcPort, dstPort, flags, nftypes.Egress, nil, size, 0)
-	return 0
 }
 
 // TrackInbound processes an inbound TCP packet and updates connection state
-func (t *TCPTracker) TrackInbound(srcIP, dstIP netip.Addr, srcPort, dstPort uint16, flags uint8, ruleID []byte, size int, dnatOrigPort uint16) {
-	t.track(srcIP, dstIP, srcPort, dstPort, flags, nftypes.Ingress, ruleID, size, dnatOrigPort)
+func (t *TCPTracker) TrackInbound(srcIP, dstIP netip.Addr, srcPort, dstPort uint16, flags uint8, ruleID []byte, size int) {
+	t.track(srcIP, dstIP, srcPort, dstPort, flags, nftypes.Ingress, ruleID, size)
 }
 
 // track is the common implementation for tracking both inbound and outbound connections
-func (t *TCPTracker) track(srcIP, dstIP netip.Addr, srcPort, dstPort uint16, flags uint8, direction nftypes.Direction, ruleID []byte, size int, origPort uint16) {
-	key, _, exists := t.updateIfExists(srcIP, dstIP, srcPort, dstPort, flags, direction, size)
+func (t *TCPTracker) track(srcIP, dstIP netip.Addr, srcPort, dstPort uint16, flags uint8, direction nftypes.Direction, ruleID []byte, size int) {
+	key, exists := t.updateIfExists(srcIP, dstIP, srcPort, dstPort, flags, direction, size)
 	if exists || flags&TCPSyn == 0 {
 		return
 	}
@@ -212,13 +210,8 @@ func (t *TCPTracker) track(srcIP, dstIP netip.Addr, srcPort, dstPort uint16, fla
 
 	conn.tombstone.Store(false)
 	conn.state.Store(int32(TCPStateNew))
-	conn.DNATOrigPort.Store(uint32(origPort))
 
-	if origPort != 0 {
-		t.logger.Trace4("New %s TCP connection: %s (port DNAT %d -> %d)", direction, key, origPort, dstPort)
-	} else {
-		t.logger.Trace2("New %s TCP connection: %s", direction, key)
-	}
+	t.logger.Trace2("New %s TCP connection: %s", direction, key)
 	t.updateState(key, conn, flags, direction, size)
 
 	t.mutex.Lock()
@@ -456,21 +449,6 @@ func (t *TCPTracker) cleanup() {
 	}
 }
 
-// GetConnection safely retrieves a connection state
-func (t *TCPTracker) GetConnection(srcIP netip.Addr, srcPort uint16, dstIP netip.Addr, dstPort uint16) (*TCPConnTrack, bool) {
-	t.mutex.RLock()
-	defer t.mutex.RUnlock()
-
-	key := ConnKey{
-		SrcIP:   srcIP,
-		DstIP:   dstIP,
-		SrcPort: srcPort,
-		DstPort: dstPort,
-	}
-	conn, exists := t.connections[key]
-	return conn, exists
-}
-
 // Close stops the cleanup routine and releases resources
 func (t *TCPTracker) Close() {
 	t.tickerCancel()

client/firewall/uspfilter/conntrack/tcp_test.go

@@ -603,7 +603,7 @@ func TestTCPInboundInitiatedConnection(t *testing.T) {
 	serverPort := uint16(80)
 
 	// 1. Client sends SYN (we receive it as inbound)
-	tracker.TrackInbound(clientIP, serverIP, clientPort, serverPort, TCPSyn, nil, 100, 0)
+	tracker.TrackInbound(clientIP, serverIP, clientPort, serverPort, TCPSyn, nil, 100)
 
 	key := ConnKey{
 		SrcIP:   clientIP,
@@ -623,12 +623,12 @@ func TestTCPInboundInitiatedConnection(t *testing.T) {
 	tracker.TrackOutbound(serverIP, clientIP, serverPort, clientPort, TCPSyn|TCPAck, 100)
 
 	// 3. Client sends ACK to complete handshake
-	tracker.TrackInbound(clientIP, serverIP, clientPort, serverPort, TCPAck, nil, 100, 0)
+	tracker.TrackInbound(clientIP, serverIP, clientPort, serverPort, TCPAck, nil, 100)
 	require.Equal(t, TCPStateEstablished, conn.GetState(), "Connection should be ESTABLISHED after handshake completion")
 
 	// 4. Test data transfer
 	// Client sends data
-	tracker.TrackInbound(clientIP, serverIP, clientPort, serverPort, TCPPush|TCPAck, nil, 1000, 0)
+	tracker.TrackInbound(clientIP, serverIP, clientPort, serverPort, TCPPush|TCPAck, nil, 1000)
 
 	// Server sends ACK for data
 	tracker.TrackOutbound(serverIP, clientIP, serverPort, clientPort, TCPAck, 100)
@@ -637,7 +637,7 @@ func TestTCPInboundInitiatedConnection(t *testing.T) {
 	tracker.TrackOutbound(serverIP, clientIP, serverPort, clientPort, TCPPush|TCPAck, 1500)
 
 	// Client sends ACK for data
-	tracker.TrackInbound(clientIP, serverIP, clientPort, serverPort, TCPAck, nil, 100, 0)
+	tracker.TrackInbound(clientIP, serverIP, clientPort, serverPort, TCPAck, nil, 100)
 
 	// Verify state and counters
 	require.Equal(t, TCPStateEstablished, conn.GetState())

client/firewall/uspfilter/conntrack/udp.go

@@ -58,23 +58,20 @@ func NewUDPTracker(timeout time.Duration, logger *nblog.Logger, flowLogger nftyp
 	return tracker
 }
 
-// TrackOutbound records an outbound UDP connection and returns the original port if DNAT reversal is needed
-func (t *UDPTracker) TrackOutbound(srcIP netip.Addr, dstIP netip.Addr, srcPort uint16, dstPort uint16, size int) uint16 {
-	_, origPort, exists := t.updateIfExists(dstIP, srcIP, dstPort, srcPort, nftypes.Egress, size)
-	if exists {
-		return origPort
+// TrackOutbound records an outbound UDP connection
+func (t *UDPTracker) TrackOutbound(srcIP netip.Addr, dstIP netip.Addr, srcPort uint16, dstPort uint16, size int) {
+	if _, exists := t.updateIfExists(dstIP, srcIP, dstPort, srcPort, nftypes.Egress, size); !exists {
+		// if (inverted direction) conn is not tracked, track this direction
+		t.track(srcIP, dstIP, srcPort, dstPort, nftypes.Egress, nil, size)
 	}
-	// if (inverted direction) conn is not tracked, track this direction
-	t.track(srcIP, dstIP, srcPort, dstPort, nftypes.Egress, nil, size, 0)
-	return 0
 }
 
 // TrackInbound records an inbound UDP connection
-func (t *UDPTracker) TrackInbound(srcIP netip.Addr, dstIP netip.Addr, srcPort uint16, dstPort uint16, ruleID []byte, size int, dnatOrigPort uint16) {
-	t.track(srcIP, dstIP, srcPort, dstPort, nftypes.Ingress, ruleID, size, dnatOrigPort)
+func (t *UDPTracker) TrackInbound(srcIP netip.Addr, dstIP netip.Addr, srcPort uint16, dstPort uint16, ruleID []byte, size int) {
+	t.track(srcIP, dstIP, srcPort, dstPort, nftypes.Ingress, ruleID, size)
 }
 
-func (t *UDPTracker) updateIfExists(srcIP netip.Addr, dstIP netip.Addr, srcPort uint16, dstPort uint16, direction nftypes.Direction, size int) (ConnKey, uint16, bool) {
+func (t *UDPTracker) updateIfExists(srcIP netip.Addr, dstIP netip.Addr, srcPort uint16, dstPort uint16, direction nftypes.Direction, size int) (ConnKey, bool) {
 	key := ConnKey{
 		SrcIP:   srcIP,
 		DstIP:   dstIP,
@@ -89,15 +86,15 @@ func (t *UDPTracker) updateIfExists(srcIP netip.Addr, dstIP netip.Addr, srcPort
 	if exists {
 		conn.UpdateLastSeen()
 		conn.UpdateCounters(direction, size)
-		return key, uint16(conn.DNATOrigPort.Load()), true
+		return key, true
 	}
 
-	return key, 0, false
+	return key, false
 }
 
 // track is the common implementation for tracking both inbound and outbound connections
-func (t *UDPTracker) track(srcIP netip.Addr, dstIP netip.Addr, srcPort uint16, dstPort uint16, direction nftypes.Direction, ruleID []byte, size int, origPort uint16) {
-	key, _, exists := t.updateIfExists(srcIP, dstIP, srcPort, dstPort, direction, size)
+func (t *UDPTracker) track(srcIP netip.Addr, dstIP netip.Addr, srcPort uint16, dstPort uint16, direction nftypes.Direction, ruleID []byte, size int) {
+	key, exists := t.updateIfExists(srcIP, dstIP, srcPort, dstPort, direction, size)
 	if exists {
 		return
 	}
@@ -112,7 +109,6 @@ func (t *UDPTracker) track(srcIP netip.Addr, dstIP netip.Addr, srcPort uint16, d
 		SourcePort: srcPort,
 		DestPort:   dstPort,
 	}
-	conn.DNATOrigPort.Store(uint32(origPort))
 	conn.UpdateLastSeen()
 	conn.UpdateCounters(direction, size)
 
@@ -120,11 +116,7 @@ func (t *UDPTracker) track(srcIP netip.Addr, dstIP netip.Addr, srcPort uint16, d
 	t.connections[key] = conn
 	t.mutex.Unlock()
 
-	if origPort != 0 {
-		t.logger.Trace4("New %s UDP connection: %s (port DNAT %d -> %d)", direction, key, origPort, dstPort)
-	} else {
-		t.logger.Trace2("New %s UDP connection: %s", direction, key)
-	}
+	t.logger.Trace2("New %s UDP connection: %s", direction, key)
 	t.sendEvent(nftypes.TypeStart, conn, ruleID)
 }
 

client/firewall/uspfilter/filter.go

@@ -1,7 +1,6 @@
 package uspfilter
 
 import (
-	"encoding/binary"
 	"errors"
 	"fmt"
 	"net"
@@ -28,12 +27,7 @@ import (
 	"github.com/netbirdio/netbird/client/internal/statemanager"
 )
 
-const (
-	layerTypeAll = 0
-
-	// ipTCPHeaderMinSize represents minimum IP (20) + TCP (20) header size for MSS calculation
-	ipTCPHeaderMinSize = 40
-)
+const layerTypeAll = 0
 
 const (
 	// EnvDisableConntrack disables the stateful filter, replies to outbound traffic won't be allowed.
@@ -42,9 +36,6 @@ const (
 	// EnvDisableUserspaceRouting disables userspace routing, to-be-routed packets will be dropped.
 	EnvDisableUserspaceRouting = "NB_DISABLE_USERSPACE_ROUTING"
 
-	// EnvDisableMSSClamping disables TCP MSS clamping for forwarded traffic.
-	EnvDisableMSSClamping = "NB_DISABLE_MSS_CLAMPING"
-
 	// EnvForceUserspaceRouter forces userspace routing even if native routing is available.
 	EnvForceUserspaceRouter = "NB_FORCE_USERSPACE_ROUTER"
 
@@ -59,12 +50,6 @@ const (
 
 var errNatNotSupported = errors.New("nat not supported with userspace firewall")
 
-// serviceKey represents a protocol/port combination for netstack service registry
-type serviceKey struct {
-	protocol gopacket.LayerType
-	port     uint16
-}
-
 // RuleSet is a set of rules grouped by a string key
 type RuleSet map[string]PeerRule
 
@@ -85,13 +70,14 @@ func (r RouteRules) Sort() {
 
 // Manager userspace firewall manager
 type Manager struct {
-	outgoingRules     map[netip.Addr]RuleSet
-	incomingDenyRules map[netip.Addr]RuleSet
-	incomingRules     map[netip.Addr]RuleSet
-	routeRules        RouteRules
-	decoders          sync.Pool
-	wgIface           common.IFaceMapper
-	nativeFirewall    firewall.Manager
+	// outgoingRules is used for hooks only
+	outgoingRules map[netip.Addr]RuleSet
+	// incomingRules is used for filtering and hooks
+	incomingRules  map[netip.Addr]RuleSet
+	routeRules     RouteRules
+	decoders       sync.Pool
+	wgIface        common.IFaceMapper
+	nativeFirewall firewall.Manager
 
 	mutex sync.RWMutex
 
@@ -124,17 +110,6 @@ type Manager struct {
 	dnatMappings map[netip.Addr]netip.Addr
 	dnatMutex    sync.RWMutex
 	dnatBiMap    *biDNATMap
-
-	portDNATEnabled atomic.Bool
-	portDNATRules   []portDNATRule
-	portDNATMutex   sync.RWMutex
-
-	netstackServices     map[serviceKey]struct{}
-	netstackServiceMutex sync.RWMutex
-
-	mtu             uint16
-	mssClampValue   uint16
-	mssClampEnabled bool
 }
 
 // decoder for packages
@@ -148,21 +123,19 @@ type decoder struct {
 	icmp6   layers.ICMPv6
 	decoded []gopacket.LayerType
 	parser  *gopacket.DecodingLayerParser
-
-	dnatOrigPort uint16
 }
 
 // Create userspace firewall manager constructor
-func Create(iface common.IFaceMapper, disableServerRoutes bool, flowLogger nftypes.FlowLogger, mtu uint16) (*Manager, error) {
-	return create(iface, nil, disableServerRoutes, flowLogger, mtu)
+func Create(iface common.IFaceMapper, disableServerRoutes bool, flowLogger nftypes.FlowLogger) (*Manager, error) {
+	return create(iface, nil, disableServerRoutes, flowLogger)
 }
 
-func CreateWithNativeFirewall(iface common.IFaceMapper, nativeFirewall firewall.Manager, disableServerRoutes bool, flowLogger nftypes.FlowLogger, mtu uint16) (*Manager, error) {
+func CreateWithNativeFirewall(iface common.IFaceMapper, nativeFirewall firewall.Manager, disableServerRoutes bool, flowLogger nftypes.FlowLogger) (*Manager, error) {
 	if nativeFirewall == nil {
 		return nil, errors.New("native firewall is nil")
 	}
 
-	mgr, err := create(iface, nativeFirewall, disableServerRoutes, flowLogger, mtu)
+	mgr, err := create(iface, nativeFirewall, disableServerRoutes, flowLogger)
 	if err != nil {
 		return nil, err
 	}
@@ -170,8 +143,8 @@ func CreateWithNativeFirewall(iface common.IFaceMapper, nativeFirewall firewall.
 	return mgr, nil
 }
 
-func parseCreateEnv() (bool, bool, bool) {
-	var disableConntrack, enableLocalForwarding, disableMSSClamping bool
+func parseCreateEnv() (bool, bool) {
+	var disableConntrack, enableLocalForwarding bool
 	var err error
 	if val := os.Getenv(EnvDisableConntrack); val != "" {
 		disableConntrack, err = strconv.ParseBool(val)
@@ -190,18 +163,12 @@ func parseCreateEnv() (bool, bool, bool) {
 			log.Warnf("failed to parse %s: %v", EnvEnableLocalForwarding, err)
 		}
 	}
-	if val := os.Getenv(EnvDisableMSSClamping); val != "" {
-		disableMSSClamping, err = strconv.ParseBool(val)
-		if err != nil {
-			log.Warnf("failed to parse %s: %v", EnvDisableMSSClamping, err)
-		}
-	}
 
-	return disableConntrack, enableLocalForwarding, disableMSSClamping
+	return disableConntrack, enableLocalForwarding
 }
 
-func create(iface common.IFaceMapper, nativeFirewall firewall.Manager, disableServerRoutes bool, flowLogger nftypes.FlowLogger, mtu uint16) (*Manager, error) {
-	disableConntrack, enableLocalForwarding, disableMSSClamping := parseCreateEnv()
+func create(iface common.IFaceMapper, nativeFirewall firewall.Manager, disableServerRoutes bool, flowLogger nftypes.FlowLogger) (*Manager, error) {
+	disableConntrack, enableLocalForwarding := parseCreateEnv()
 
 	m := &Manager{
 		decoders: sync.Pool{
@@ -219,7 +186,6 @@ func create(iface common.IFaceMapper, nativeFirewall firewall.Manager, disableSe
 		},
 		nativeFirewall:      nativeFirewall,
 		outgoingRules:       make(map[netip.Addr]RuleSet),
-		incomingDenyRules:   make(map[netip.Addr]RuleSet),
 		incomingRules:       make(map[netip.Addr]RuleSet),
 		wgIface:             iface,
 		localipmanager:      newLocalIPManager(),
@@ -230,19 +196,13 @@ func create(iface common.IFaceMapper, nativeFirewall firewall.Manager, disableSe
 		netstack:            netstack.IsEnabled(),
 		localForwarding:     enableLocalForwarding,
 		dnatMappings:        make(map[netip.Addr]netip.Addr),
-		portDNATRules:       []portDNATRule{},
-		netstackServices:    make(map[serviceKey]struct{}),
-		mtu:                 mtu,
 	}
 	m.routingEnabled.Store(false)
 
-	if !disableMSSClamping {
-		m.mssClampEnabled = true
-		m.mssClampValue = mtu - ipTCPHeaderMinSize
-	}
 	if err := m.localipmanager.UpdateLocalIPs(iface); err != nil {
 		return nil, fmt.Errorf("update local IPs: %w", err)
 	}
+
 	if disableConntrack {
 		log.Info("conntrack is disabled")
 	} else {
@@ -250,11 +210,14 @@ func create(iface common.IFaceMapper, nativeFirewall firewall.Manager, disableSe
 		m.icmpTracker = conntrack.NewICMPTracker(conntrack.DefaultICMPTimeout, m.logger, flowLogger)
 		m.tcpTracker = conntrack.NewTCPTracker(conntrack.DefaultTCPTimeout, m.logger, flowLogger)
 	}
+
+	// netstack needs the forwarder for local traffic
 	if m.netstack && m.localForwarding {
 		if err := m.initForwarder(); err != nil {
 			log.Errorf("failed to initialize forwarder: %v", err)
 		}
 	}
+
 	if err := iface.SetFilter(m); err != nil {
 		return nil, fmt.Errorf("set filter: %w", err)
 	}
@@ -357,7 +320,7 @@ func (m *Manager) initForwarder() error {
 		return errors.New("forwarding not supported")
 	}
 
-	forwarder, err := forwarder.New(m.wgIface, m.logger, m.flowLogger, m.netstack, m.mtu)
+	forwarder, err := forwarder.New(m.wgIface, m.logger, m.flowLogger, m.netstack)
 	if err != nil {
 		m.routingEnabled.Store(false)
 		return fmt.Errorf("create forwarder: %w", err)
@@ -454,17 +417,10 @@ func (m *Manager) AddPeerFiltering(
 	}
 
 	m.mutex.Lock()
-	var targetMap map[netip.Addr]RuleSet
-	if r.drop {
-		targetMap = m.incomingDenyRules
-	} else {
-		targetMap = m.incomingRules
+	if _, ok := m.incomingRules[r.ip]; !ok {
+		m.incomingRules[r.ip] = make(RuleSet)
 	}
-
-	if _, ok := targetMap[r.ip]; !ok {
-		targetMap[r.ip] = make(RuleSet)
-	}
-	targetMap[r.ip][r.id] = r
+	m.incomingRules[r.ip][r.id] = r
 	m.mutex.Unlock()
 	return []firewall.Rule{&r}, nil
 }
@@ -551,24 +507,10 @@ func (m *Manager) DeletePeerRule(rule firewall.Rule) error {
 		return fmt.Errorf("delete rule: invalid rule type: %T", rule)
 	}
 
-	var sourceMap map[netip.Addr]RuleSet
-	if r.drop {
-		sourceMap = m.incomingDenyRules
-	} else {
-		sourceMap = m.incomingRules
-	}
-
-	if ruleset, ok := sourceMap[r.ip]; ok {
-		if _, exists := ruleset[r.id]; !exists {
-			return fmt.Errorf("delete rule: no rule with such id: %v", r.id)
-		}
-		delete(ruleset, r.id)
-		if len(ruleset) == 0 {
-			delete(sourceMap, r.ip)
-		}
-	} else {
+	if _, ok := m.incomingRules[r.ip][r.id]; !ok {
 		return fmt.Errorf("delete rule: no rule with such id: %v", r.id)
 	}
+	delete(m.incomingRules[r.ip], r.id)
 
 	return nil
 }
@@ -630,7 +572,7 @@ func (m *Manager) UpdateSet(set firewall.Set, prefixes []netip.Prefix) error {
 	return nil
 }
 
-// FilterOutbound filters outgoing packets
+// FilterOutBound filters outgoing packets
 func (m *Manager) FilterOutbound(packetData []byte, size int) bool {
 	return m.filterOutbound(packetData, size)
 }
@@ -663,20 +605,11 @@ func (m *Manager) filterOutbound(packetData []byte, size int) bool {
 		return false
 	}
 
-	switch d.decoded[1] {
-	case layers.LayerTypeUDP:
-		if m.udpHooksDrop(uint16(d.udp.DstPort), dstIP, packetData) {
-			return true
-		}
-	case layers.LayerTypeTCP:
-		// Clamp MSS on all TCP SYN packets, including those from local IPs.
-		// SNATed routed traffic may appear as local IP but still requires clamping.
-		if m.mssClampEnabled {
-			m.clampTCPMSS(packetData, d)
-		}
+	if d.decoded[1] == layers.LayerTypeUDP && m.udpHooksDrop(uint16(d.udp.DstPort), dstIP, packetData) {
+		return true
 	}
 
-	m.trackOutbound(d, srcIP, dstIP, packetData, size)
+	m.trackOutbound(d, srcIP, dstIP, size)
 	m.translateOutboundDNAT(packetData, d)
 
 	return false
@@ -720,117 +653,14 @@ func getTCPFlags(tcp *layers.TCP) uint8 {
 	return flags
 }
 
-// clampTCPMSS clamps the TCP MSS option in SYN and SYN-ACK packets to prevent fragmentation.
-// Both sides advertise their MSS during connection establishment, so we need to clamp both.
-func (m *Manager) clampTCPMSS(packetData []byte, d *decoder) bool {
-	if !d.tcp.SYN {
-		return false
-	}
-	if len(d.tcp.Options) == 0 {
-		return false
-	}
-
-	mssOptionIndex := -1
-	var currentMSS uint16
-	for i, opt := range d.tcp.Options {
-		if opt.OptionType == layers.TCPOptionKindMSS && len(opt.OptionData) == 2 {
-			currentMSS = binary.BigEndian.Uint16(opt.OptionData)
-			if currentMSS > m.mssClampValue {
-				mssOptionIndex = i
-				break
-			}
-		}
-	}
-
-	if mssOptionIndex == -1 {
-		return false
-	}
-
-	ipHeaderSize := int(d.ip4.IHL) * 4
-	if ipHeaderSize < 20 {
-		return false
-	}
-
-	if !m.updateMSSOption(packetData, d, mssOptionIndex, ipHeaderSize) {
-		return false
-	}
-
-	m.logger.Trace2("Clamped TCP MSS from %d to %d", currentMSS, m.mssClampValue)
-	return true
-}
-
-func (m *Manager) updateMSSOption(packetData []byte, d *decoder, mssOptionIndex, ipHeaderSize int) bool {
-	tcpHeaderStart := ipHeaderSize
-	tcpOptionsStart := tcpHeaderStart + 20
-
-	optOffset := tcpOptionsStart
-	for j := 0; j < mssOptionIndex; j++ {
-		switch d.tcp.Options[j].OptionType {
-		case layers.TCPOptionKindEndList, layers.TCPOptionKindNop:
-			optOffset++
-		default:
-			optOffset += 2 + len(d.tcp.Options[j].OptionData)
-		}
-	}
-
-	mssValueOffset := optOffset + 2
-	binary.BigEndian.PutUint16(packetData[mssValueOffset:mssValueOffset+2], m.mssClampValue)
-
-	m.recalculateTCPChecksum(packetData, d, tcpHeaderStart)
-	return true
-}
-
-func (m *Manager) recalculateTCPChecksum(packetData []byte, d *decoder, tcpHeaderStart int) {
-	tcpLayer := packetData[tcpHeaderStart:]
-	tcpLength := len(packetData) - tcpHeaderStart
-
-	tcpLayer[16] = 0
-	tcpLayer[17] = 0
-
-	var pseudoSum uint32
-	pseudoSum += uint32(d.ip4.SrcIP[0])<<8 | uint32(d.ip4.SrcIP[1])
-	pseudoSum += uint32(d.ip4.SrcIP[2])<<8 | uint32(d.ip4.SrcIP[3])
-	pseudoSum += uint32(d.ip4.DstIP[0])<<8 | uint32(d.ip4.DstIP[1])
-	pseudoSum += uint32(d.ip4.DstIP[2])<<8 | uint32(d.ip4.DstIP[3])
-	pseudoSum += uint32(d.ip4.Protocol)
-	pseudoSum += uint32(tcpLength)
-
-	var sum uint32 = pseudoSum
-	for i := 0; i < tcpLength-1; i += 2 {
-		sum += uint32(tcpLayer[i])<<8 | uint32(tcpLayer[i+1])
-	}
-	if tcpLength%2 == 1 {
-		sum += uint32(tcpLayer[tcpLength-1]) << 8
-	}
-
-	for sum > 0xFFFF {
-		sum = (sum & 0xFFFF) + (sum >> 16)
-	}
-
-	checksum := ^uint16(sum)
-	binary.BigEndian.PutUint16(tcpLayer[16:18], checksum)
-}
-
-func (m *Manager) trackOutbound(d *decoder, srcIP, dstIP netip.Addr, packetData []byte, size int) {
+func (m *Manager) trackOutbound(d *decoder, srcIP, dstIP netip.Addr, size int) {
 	transport := d.decoded[1]
 	switch transport {
 	case layers.LayerTypeUDP:
-		origPort := m.udpTracker.TrackOutbound(srcIP, dstIP, uint16(d.udp.SrcPort), uint16(d.udp.DstPort), size)
-		if origPort == 0 {
-			break
-		}
-		if err := m.rewriteUDPPort(packetData, d, origPort, sourcePortOffset); err != nil {
-			m.logger.Error1("failed to rewrite UDP port: %v", err)
-		}
+		m.udpTracker.TrackOutbound(srcIP, dstIP, uint16(d.udp.SrcPort), uint16(d.udp.DstPort), size)
 	case layers.LayerTypeTCP:
 		flags := getTCPFlags(&d.tcp)
-		origPort := m.tcpTracker.TrackOutbound(srcIP, dstIP, uint16(d.tcp.SrcPort), uint16(d.tcp.DstPort), flags, size)
-		if origPort == 0 {
-			break
-		}
-		if err := m.rewriteTCPPort(packetData, d, origPort, sourcePortOffset); err != nil {
-			m.logger.Error1("failed to rewrite TCP port: %v", err)
-		}
+		m.tcpTracker.TrackOutbound(srcIP, dstIP, uint16(d.tcp.SrcPort), uint16(d.tcp.DstPort), flags, size)
 	case layers.LayerTypeICMPv4:
 		m.icmpTracker.TrackOutbound(srcIP, dstIP, d.icmp4.Id, d.icmp4.TypeCode, d.icmp4.Payload, size)
 	}
@@ -840,15 +670,13 @@ func (m *Manager) trackInbound(d *decoder, srcIP, dstIP netip.Addr, ruleID []byt
 	transport := d.decoded[1]
 	switch transport {
 	case layers.LayerTypeUDP:
-		m.udpTracker.TrackInbound(srcIP, dstIP, uint16(d.udp.SrcPort), uint16(d.udp.DstPort), ruleID, size, d.dnatOrigPort)
+		m.udpTracker.TrackInbound(srcIP, dstIP, uint16(d.udp.SrcPort), uint16(d.udp.DstPort), ruleID, size)
 	case layers.LayerTypeTCP:
 		flags := getTCPFlags(&d.tcp)
-		m.tcpTracker.TrackInbound(srcIP, dstIP, uint16(d.tcp.SrcPort), uint16(d.tcp.DstPort), flags, ruleID, size, d.dnatOrigPort)
+		m.tcpTracker.TrackInbound(srcIP, dstIP, uint16(d.tcp.SrcPort), uint16(d.tcp.DstPort), flags, ruleID, size)
 	case layers.LayerTypeICMPv4:
 		m.icmpTracker.TrackInbound(srcIP, dstIP, d.icmp4.Id, d.icmp4.TypeCode, ruleID, d.icmp4.Payload, size)
 	}
-
-	d.dnatOrigPort = 0
 }
 
 // udpHooksDrop checks if any UDP hooks should drop the packet
@@ -910,20 +738,10 @@ func (m *Manager) filterInbound(packetData []byte, size int) bool {
 		return false
 	}
 
-	// TODO: optimize port DNAT by caching matched rules in conntrack
-	if translated := m.translateInboundPortDNAT(packetData, d, srcIP, dstIP); translated {
-		// Re-decode after port DNAT translation to update port information
-		if err := d.parser.DecodeLayers(packetData, &d.decoded); err != nil {
-			m.logger.Error1("failed to re-decode packet after port DNAT: %v", err)
-			return true
-		}
-		srcIP, dstIP = m.extractIPs(d)
-	}
-
 	if translated := m.translateInboundReverse(packetData, d); translated {
 		// Re-decode after translation to get original addresses
 		if err := d.parser.DecodeLayers(packetData, &d.decoded); err != nil {
-			m.logger.Error1("failed to re-decode packet after reverse DNAT: %v", err)
+			m.logger.Error1("Failed to re-decode packet after reverse DNAT: %v", err)
 			return true
 		}
 		srcIP, dstIP = m.extractIPs(d)
@@ -943,7 +761,7 @@ func (m *Manager) filterInbound(packetData []byte, size int) bool {
 // handleLocalTraffic handles local traffic.
 // If it returns true, the packet should be dropped.
 func (m *Manager) handleLocalTraffic(d *decoder, srcIP, dstIP netip.Addr, packetData []byte, size int) bool {
-	ruleID, blocked := m.peerACLsBlock(srcIP, d, packetData)
+	ruleID, blocked := m.peerACLsBlock(srcIP, packetData, m.incomingRules, d)
 	if blocked {
 		_, pnum := getProtocolFromPacket(d)
 		srcPort, dstPort := getPortsFromPacket(d)
@@ -968,7 +786,9 @@ func (m *Manager) handleLocalTraffic(d *decoder, srcIP, dstIP netip.Addr, packet
 		return true
 	}
 
-	if m.shouldForward(d, dstIP) {
+	// If requested we pass local traffic to internal interfaces to the forwarder.
+	// netstack doesn't have an interface to forward packets to the native stack so we always need to use the forwarder.
+	if m.localForwarding && (m.netstack || dstIP != m.wgIface.Address().IP) {
 		return m.handleForwardedLocalTraffic(packetData)
 	}
 
@@ -1151,28 +971,26 @@ func (m *Manager) isSpecialICMP(d *decoder) bool {
 		icmpType == layers.ICMPv4TypeTimeExceeded
 }
 
-func (m *Manager) peerACLsBlock(srcIP netip.Addr, d *decoder, packetData []byte) ([]byte, bool) {
+func (m *Manager) peerACLsBlock(srcIP netip.Addr, packetData []byte, rules map[netip.Addr]RuleSet, d *decoder) ([]byte, bool) {
 	m.mutex.RLock()
 	defer m.mutex.RUnlock()
-
 	if m.isSpecialICMP(d) {
 		return nil, false
 	}
 
-	if mgmtId, filter, ok := validateRule(srcIP, packetData, m.incomingDenyRules[srcIP], d); ok {
+	if mgmtId, filter, ok := validateRule(srcIP, packetData, rules[srcIP], d); ok {
 		return mgmtId, filter
 	}
 
-	if mgmtId, filter, ok := validateRule(srcIP, packetData, m.incomingRules[srcIP], d); ok {
-		return mgmtId, filter
-	}
-	if mgmtId, filter, ok := validateRule(srcIP, packetData, m.incomingRules[netip.IPv4Unspecified()], d); ok {
-		return mgmtId, filter
-	}
-	if mgmtId, filter, ok := validateRule(srcIP, packetData, m.incomingRules[netip.IPv6Unspecified()], d); ok {
+	if mgmtId, filter, ok := validateRule(srcIP, packetData, rules[netip.IPv4Unspecified()], d); ok {
 		return mgmtId, filter
 	}
 
+	if mgmtId, filter, ok := validateRule(srcIP, packetData, rules[netip.IPv6Unspecified()], d); ok {
+		return mgmtId, filter
+	}
+
+	// Default policy: DROP ALL
 	return nil, true
 }
 
@@ -1195,7 +1013,6 @@ func portsMatch(rulePort *firewall.Port, packetPort uint16) bool {
 
 func validateRule(ip netip.Addr, packetData []byte, rules map[string]PeerRule, d *decoder) ([]byte, bool, bool) {
 	payloadLayer := d.decoded[1]
-
 	for _, rule := range rules {
 		if rule.matchByIP && ip.Compare(rule.ip) != 0 {
 			continue
@@ -1228,7 +1045,6 @@ func validateRule(ip netip.Addr, packetData []byte, rules map[string]PeerRule, d
 			return rule.mgmtId, rule.drop, true
 		}
 	}
-
 	return nil, false, false
 }
 
@@ -1300,7 +1116,6 @@ func (m *Manager) AddUDPPacketHook(in bool, ip netip.Addr, dPort uint16, hook fu
 
 	m.mutex.Lock()
 	if in {
-		// Incoming UDP hooks are stored in allow rules map
 		if _, ok := m.incomingRules[r.ip]; !ok {
 			m.incomingRules[r.ip] = make(map[string]PeerRule)
 		}
@@ -1321,7 +1136,6 @@ func (m *Manager) RemovePacketHook(hookID string) error {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
 
-	// Check incoming hooks (stored in allow rules)
 	for _, arr := range m.incomingRules {
 		for _, r := range arr {
 			if r.id == hookID {
@@ -1330,7 +1144,6 @@ func (m *Manager) RemovePacketHook(hookID string) error {
 			}
 		}
 	}
-	// Check outgoing hooks
 	for _, arr := range m.outgoingRules {
 		for _, r := range arr {
 			if r.id == hookID {
@@ -1402,86 +1215,3 @@ func (m *Manager) DisableRouting() error {
 
 	return nil
 }
-
-// RegisterNetstackService registers a service as listening on the netstack for the given protocol and port
-func (m *Manager) RegisterNetstackService(protocol nftypes.Protocol, port uint16) {
-	m.netstackServiceMutex.Lock()
-	defer m.netstackServiceMutex.Unlock()
-	layerType := m.protocolToLayerType(protocol)
-	key := serviceKey{protocol: layerType, port: port}
-	m.netstackServices[key] = struct{}{}
-	m.logger.Debug3("RegisterNetstackService: registered %s:%d (layerType=%s)", protocol, port, layerType)
-	m.logger.Debug1("RegisterNetstackService: current registry size: %d", len(m.netstackServices))
-}
-
-// UnregisterNetstackService removes a service from the netstack registry
-func (m *Manager) UnregisterNetstackService(protocol nftypes.Protocol, port uint16) {
-	m.netstackServiceMutex.Lock()
-	defer m.netstackServiceMutex.Unlock()
-	layerType := m.protocolToLayerType(protocol)
-	key := serviceKey{protocol: layerType, port: port}
-	delete(m.netstackServices, key)
-	m.logger.Debug2("Unregistered netstack service on protocol %s port %d", protocol, port)
-}
-
-// protocolToLayerType converts nftypes.Protocol to gopacket.LayerType for internal use
-func (m *Manager) protocolToLayerType(protocol nftypes.Protocol) gopacket.LayerType {
-	switch protocol {
-	case nftypes.TCP:
-		return layers.LayerTypeTCP
-	case nftypes.UDP:
-		return layers.LayerTypeUDP
-	case nftypes.ICMP:
-		return layers.LayerTypeICMPv4
-	default:
-		return gopacket.LayerType(0) // Invalid/unknown
-	}
-}
-
-// shouldForward determines if a packet should be forwarded to the forwarder.
-// The forwarder handles routing packets to the native OS network stack.
-// Returns true if packet should go to the forwarder, false if it should go to netstack listeners or the native stack directly.
-func (m *Manager) shouldForward(d *decoder, dstIP netip.Addr) bool {
-	// not enabled, never forward
-	if !m.localForwarding {
-		return false
-	}
-
-	// netstack always needs to forward because it's lacking a native interface
-	// exception for registered netstack services, those should go to netstack listeners
-	if m.netstack {
-		return !m.hasMatchingNetstackService(d)
-	}
-
-	// traffic to our other local interfaces (not NetBird IP) - always forward
-	if dstIP != m.wgIface.Address().IP {
-		return true
-	}
-
-	// traffic to our NetBird IP, not netstack mode - send to netstack listeners
-	return false
-}
-
-// hasMatchingNetstackService checks if there's a registered netstack service for this packet
-func (m *Manager) hasMatchingNetstackService(d *decoder) bool {
-	if len(d.decoded) < 2 {
-		return false
-	}
-
-	var dstPort uint16
-	switch d.decoded[1] {
-	case layers.LayerTypeTCP:
-		dstPort = uint16(d.tcp.DstPort)
-	case layers.LayerTypeUDP:
-		dstPort = uint16(d.udp.DstPort)
-	default:
-		return false
-	}
-
-	key := serviceKey{protocol: d.decoded[1], port: dstPort}
-	m.netstackServiceMutex.RLock()
-	_, exists := m.netstackServices[key]
-	m.netstackServiceMutex.RUnlock()
-
-	return exists
-}

client/firewall/uspfilter/filter_bench_test.go

@@ -17,7 +17,6 @@ import (
 
 	fw "github.com/netbirdio/netbird/client/firewall/manager"
 	"github.com/netbirdio/netbird/client/firewall/uspfilter/conntrack"
-	"github.com/netbirdio/netbird/client/iface"
 	"github.com/netbirdio/netbird/client/iface/device"
 )
 
@@ -170,7 +169,7 @@ func BenchmarkCoreFiltering(b *testing.B) {
 				// Create manager and basic setup
 				manager, _ := Create(&IFaceMock{
 					SetFilterFunc: func(device.PacketFilter) error { return nil },
-				}, false, flowLogger, iface.DefaultMTU)
+				}, false, flowLogger)
 				defer b.Cleanup(func() {
 					require.NoError(b, manager.Close(nil))
 				})
@@ -210,7 +209,7 @@ func BenchmarkStateScaling(b *testing.B) {
 		b.Run(fmt.Sprintf("conns_%d", count), func(b *testing.B) {
 			manager, _ := Create(&IFaceMock{
 				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false, flowLogger, iface.DefaultMTU)
+			}, false, flowLogger)
 			b.Cleanup(func() {
 				require.NoError(b, manager.Close(nil))
 			})
@@ -253,7 +252,7 @@ func BenchmarkEstablishmentOverhead(b *testing.B) {
 		b.Run(sc.name, func(b *testing.B) {
 			manager, _ := Create(&IFaceMock{
 				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false, flowLogger, iface.DefaultMTU)
+			}, false, flowLogger)
 			b.Cleanup(func() {
 				require.NoError(b, manager.Close(nil))
 			})
@@ -411,7 +410,7 @@ func BenchmarkRoutedNetworkReturn(b *testing.B) {
 		b.Run(sc.name, func(b *testing.B) {
 			manager, _ := Create(&IFaceMock{
 				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false, flowLogger, iface.DefaultMTU)
+			}, false, flowLogger)
 			b.Cleanup(func() {
 				require.NoError(b, manager.Close(nil))
 			})
@@ -538,7 +537,7 @@ func BenchmarkLongLivedConnections(b *testing.B) {
 
 			manager, _ := Create(&IFaceMock{
 				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false, flowLogger, iface.DefaultMTU)
+			}, false, flowLogger)
 			defer b.Cleanup(func() {
 				require.NoError(b, manager.Close(nil))
 			})
@@ -621,7 +620,7 @@ func BenchmarkShortLivedConnections(b *testing.B) {
 
 			manager, _ := Create(&IFaceMock{
 				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false, flowLogger, iface.DefaultMTU)
+			}, false, flowLogger)
 			defer b.Cleanup(func() {
 				require.NoError(b, manager.Close(nil))
 			})
@@ -732,7 +731,7 @@ func BenchmarkParallelLongLivedConnections(b *testing.B) {
 
 			manager, _ := Create(&IFaceMock{
 				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false, flowLogger, iface.DefaultMTU)
+			}, false, flowLogger)
 			defer b.Cleanup(func() {
 				require.NoError(b, manager.Close(nil))
 			})
@@ -812,7 +811,7 @@ func BenchmarkParallelShortLivedConnections(b *testing.B) {
 
 			manager, _ := Create(&IFaceMock{
 				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false, flowLogger, iface.DefaultMTU)
+			}, false, flowLogger)
 			defer b.Cleanup(func() {
 				require.NoError(b, manager.Close(nil))
 			})
@@ -897,6 +896,38 @@ func BenchmarkParallelShortLivedConnections(b *testing.B) {
 	}
 }
 
+// generateTCPPacketWithFlags creates a TCP packet with specific flags
+func generateTCPPacketWithFlags(b *testing.B, srcIP, dstIP net.IP, srcPort, dstPort, flags uint16) []byte {
+	b.Helper()
+
+	ipv4 := &layers.IPv4{
+		TTL:      64,
+		Version:  4,
+		SrcIP:    srcIP,
+		DstIP:    dstIP,
+		Protocol: layers.IPProtocolTCP,
+	}
+
+	tcp := &layers.TCP{
+		SrcPort: layers.TCPPort(srcPort),
+		DstPort: layers.TCPPort(dstPort),
+	}
+
+	// Set TCP flags
+	tcp.SYN = (flags & uint16(conntrack.TCPSyn)) != 0
+	tcp.ACK = (flags & uint16(conntrack.TCPAck)) != 0
+	tcp.PSH = (flags & uint16(conntrack.TCPPush)) != 0
+	tcp.RST = (flags & uint16(conntrack.TCPRst)) != 0
+	tcp.FIN = (flags & uint16(conntrack.TCPFin)) != 0
+
+	require.NoError(b, tcp.SetNetworkLayerForChecksum(ipv4))
+
+	buf := gopacket.NewSerializeBuffer()
+	opts := gopacket.SerializeOptions{ComputeChecksums: true, FixLengths: true}
+	require.NoError(b, gopacket.SerializeLayers(buf, opts, ipv4, tcp, gopacket.Payload("test")))
+	return buf.Bytes()
+}
+
 func BenchmarkRouteACLs(b *testing.B) {
 	manager := setupRoutedManager(b, "10.10.0.100/16")
 
@@ -959,231 +990,3 @@ func BenchmarkRouteACLs(b *testing.B) {
 		}
 	}
 }
-
-// BenchmarkMSSClamping benchmarks the MSS clamping impact on filterOutbound.
-// This shows the overhead difference between the common case (non-SYN packets, fast path)
-// and the rare case (SYN packets that need clamping, expensive path).
-func BenchmarkMSSClamping(b *testing.B) {
-	scenarios := []struct {
-		name        string
-		description string
-		genPacket   func(*testing.B, net.IP, net.IP) []byte
-		frequency   string
-	}{
-		{
-			name:        "syn_needs_clamp",
-			description: "SYN packet needing MSS clamping",
-			genPacket: func(b *testing.B, src, dst net.IP) []byte {
-				return generateSYNPacketWithMSS(b, src, dst, 12345, 80, 1460)
-			},
-			frequency: "~0.1% of traffic - EXPENSIVE",
-		},
-		{
-			name:        "syn_no_clamp_needed",
-			description: "SYN packet with already-small MSS",
-			genPacket: func(b *testing.B, src, dst net.IP) []byte {
-				return generateSYNPacketWithMSS(b, src, dst, 12345, 80, 1200)
-			},
-			frequency: "~0.05% of traffic",
-		},
-		{
-			name:        "tcp_ack",
-			description: "Non-SYN TCP packet (ACK, data transfer)",
-			genPacket: func(b *testing.B, src, dst net.IP) []byte {
-				return generateTCPPacketWithFlags(b, src, dst, 12345, 80, uint16(conntrack.TCPAck))
-			},
-			frequency: "~60-70% of traffic - FAST PATH",
-		},
-		{
-			name:        "tcp_psh_ack",
-			description: "TCP data packet (PSH+ACK)",
-			genPacket: func(b *testing.B, src, dst net.IP) []byte {
-				return generateTCPPacketWithFlags(b, src, dst, 12345, 80, uint16(conntrack.TCPPush|conntrack.TCPAck))
-			},
-			frequency: "~10-20% of traffic - FAST PATH",
-		},
-		{
-			name:        "udp",
-			description: "UDP packet",
-			genPacket: func(b *testing.B, src, dst net.IP) []byte {
-				return generatePacket(b, src, dst, 12345, 80, layers.IPProtocolUDP)
-			},
-			frequency: "~20-30% of traffic - FAST PATH",
-		},
-	}
-
-	for _, sc := range scenarios {
-		b.Run(sc.name, func(b *testing.B) {
-			manager, err := Create(&IFaceMock{
-				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false, flowLogger, iface.DefaultMTU)
-			require.NoError(b, err)
-			defer func() {
-				require.NoError(b, manager.Close(nil))
-			}()
-
-			manager.mssClampEnabled = true
-			manager.mssClampValue = 1240
-
-			srcIP := net.ParseIP("100.64.0.2")
-			dstIP := net.ParseIP("8.8.8.8")
-			packet := sc.genPacket(b, srcIP, dstIP)
-
-			b.ReportAllocs()
-			b.ResetTimer()
-			for i := 0; i < b.N; i++ {
-				manager.filterOutbound(packet, len(packet))
-			}
-		})
-	}
-}
-
-// BenchmarkMSSClampingOverhead compares overhead of MSS clamping enabled vs disabled
-// for the common case (non-SYN TCP packets).
-func BenchmarkMSSClampingOverhead(b *testing.B) {
-	scenarios := []struct {
-		name      string
-		enabled   bool
-		genPacket func(*testing.B, net.IP, net.IP) []byte
-	}{
-		{
-			name:    "disabled_tcp_ack",
-			enabled: false,
-			genPacket: func(b *testing.B, src, dst net.IP) []byte {
-				return generateTCPPacketWithFlags(b, src, dst, 12345, 80, uint16(conntrack.TCPAck))
-			},
-		},
-		{
-			name:    "enabled_tcp_ack",
-			enabled: true,
-			genPacket: func(b *testing.B, src, dst net.IP) []byte {
-				return generateTCPPacketWithFlags(b, src, dst, 12345, 80, uint16(conntrack.TCPAck))
-			},
-		},
-		{
-			name:    "disabled_syn_needs_clamp",
-			enabled: false,
-			genPacket: func(b *testing.B, src, dst net.IP) []byte {
-				return generateSYNPacketWithMSS(b, src, dst, 12345, 80, 1460)
-			},
-		},
-		{
-			name:    "enabled_syn_needs_clamp",
-			enabled: true,
-			genPacket: func(b *testing.B, src, dst net.IP) []byte {
-				return generateSYNPacketWithMSS(b, src, dst, 12345, 80, 1460)
-			},
-		},
-	}
-
-	for _, sc := range scenarios {
-		b.Run(sc.name, func(b *testing.B) {
-			manager, err := Create(&IFaceMock{
-				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false, flowLogger, iface.DefaultMTU)
-			require.NoError(b, err)
-			defer func() {
-				require.NoError(b, manager.Close(nil))
-			}()
-
-			manager.mssClampEnabled = sc.enabled
-			if sc.enabled {
-				manager.mssClampValue = 1240
-			}
-
-			srcIP := net.ParseIP("100.64.0.2")
-			dstIP := net.ParseIP("8.8.8.8")
-			packet := sc.genPacket(b, srcIP, dstIP)
-
-			b.ReportAllocs()
-			b.ResetTimer()
-			for i := 0; i < b.N; i++ {
-				manager.filterOutbound(packet, len(packet))
-			}
-		})
-	}
-}
-
-// BenchmarkMSSClampingMemory measures memory allocations for common vs rare cases
-func BenchmarkMSSClampingMemory(b *testing.B) {
-	scenarios := []struct {
-		name      string
-		genPacket func(*testing.B, net.IP, net.IP) []byte
-	}{
-		{
-			name: "tcp_ack_fast_path",
-			genPacket: func(b *testing.B, src, dst net.IP) []byte {
-				return generateTCPPacketWithFlags(b, src, dst, 12345, 80, uint16(conntrack.TCPAck))
-			},
-		},
-		{
-			name: "syn_needs_clamp",
-			genPacket: func(b *testing.B, src, dst net.IP) []byte {
-				return generateSYNPacketWithMSS(b, src, dst, 12345, 80, 1460)
-			},
-		},
-		{
-			name: "udp_fast_path",
-			genPacket: func(b *testing.B, src, dst net.IP) []byte {
-				return generatePacket(b, src, dst, 12345, 80, layers.IPProtocolUDP)
-			},
-		},
-	}
-
-	for _, sc := range scenarios {
-		b.Run(sc.name, func(b *testing.B) {
-			manager, err := Create(&IFaceMock{
-				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false, flowLogger, iface.DefaultMTU)
-			require.NoError(b, err)
-			defer func() {
-				require.NoError(b, manager.Close(nil))
-			}()
-
-			manager.mssClampEnabled = true
-			manager.mssClampValue = 1240
-
-			srcIP := net.ParseIP("100.64.0.2")
-			dstIP := net.ParseIP("8.8.8.8")
-			packet := sc.genPacket(b, srcIP, dstIP)
-
-			b.ReportAllocs()
-			b.ResetTimer()
-			for i := 0; i < b.N; i++ {
-				manager.filterOutbound(packet, len(packet))
-			}
-		})
-	}
-}
-
-func generateSYNPacketNoMSS(b *testing.B, srcIP, dstIP net.IP, srcPort, dstPort uint16) []byte {
-	b.Helper()
-
-	ip := &layers.IPv4{
-		Version:  4,
-		IHL:      5,
-		TTL:      64,
-		Protocol: layers.IPProtocolTCP,
-		SrcIP:    srcIP,
-		DstIP:    dstIP,
-	}
-
-	tcp := &layers.TCP{
-		SrcPort: layers.TCPPort(srcPort),
-		DstPort: layers.TCPPort(dstPort),
-		SYN:     true,
-		Seq:     1000,
-		Window:  65535,
-	}
-
-	require.NoError(b, tcp.SetNetworkLayerForChecksum(ip))
-
-	buf := gopacket.NewSerializeBuffer()
-	opts := gopacket.SerializeOptions{
-		FixLengths:       true,
-		ComputeChecksums: true,
-	}
-
-	require.NoError(b, gopacket.SerializeLayers(buf, opts, ip, tcp, gopacket.Payload([]byte{})))
-	return buf.Bytes()
-}

client/firewall/uspfilter/filter_filter_test.go

@@ -12,7 +12,6 @@ import (
 	wgdevice "golang.zx2c4.com/wireguard/device"
 
 	fw "github.com/netbirdio/netbird/client/firewall/manager"
-	"github.com/netbirdio/netbird/client/iface"
 	"github.com/netbirdio/netbird/client/iface/device"
 	"github.com/netbirdio/netbird/client/iface/mocks"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
@@ -32,7 +31,7 @@ func TestPeerACLFiltering(t *testing.T) {
 		},
 	}
 
-	manager, err := Create(ifaceMock, false, flowLogger, iface.DefaultMTU)
+	manager, err := Create(ifaceMock, false, flowLogger)
 	require.NoError(t, err)
 	require.NotNil(t, manager)
 
@@ -459,31 +458,6 @@ func TestPeerACLFiltering(t *testing.T) {
 			ruleAction:      fw.ActionDrop,
 			shouldBeBlocked: true,
 		},
-		{
-			name:            "Peer ACL - Drop rule should override accept all rule",
-			srcIP:           "100.10.0.1",
-			dstIP:           "100.10.0.100",
-			proto:           fw.ProtocolTCP,
-			srcPort:         12345,
-			dstPort:         22,
-			ruleIP:          "100.10.0.1",
-			ruleProto:       fw.ProtocolTCP,
-			ruleDstPort:     &fw.Port{Values: []uint16{22}},
-			ruleAction:      fw.ActionDrop,
-			shouldBeBlocked: true,
-		},
-		{
-			name:            "Peer ACL - Drop all traffic from specific IP",
-			srcIP:           "100.10.0.99",
-			dstIP:           "100.10.0.100",
-			proto:           fw.ProtocolTCP,
-			srcPort:         12345,
-			dstPort:         80,
-			ruleIP:          "100.10.0.99",
-			ruleProto:       fw.ProtocolALL,
-			ruleAction:      fw.ActionDrop,
-			shouldBeBlocked: true,
-		},
 	}
 
 	t.Run("Implicit DROP (no rules)", func(t *testing.T) {
@@ -494,11 +468,13 @@ func TestPeerACLFiltering(t *testing.T) {
 
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {
+
 			if tc.ruleAction == fw.ActionDrop {
-				// add general accept rule for the same IP to test drop rule precedence
+				// add general accept rule to test drop rule
+				// TODO: this only works because 0.0.0.0 is tested last, we need to implement order
 				rules, err := manager.AddPeerFiltering(
 					nil,
-					net.ParseIP(tc.ruleIP),
+					net.ParseIP("0.0.0.0"),
 					fw.ProtocolALL,
 					nil,
 					nil,
@@ -617,7 +593,7 @@ func setupRoutedManager(tb testing.TB, network string) *Manager {
 		},
 	}
 
-	manager, err := Create(ifaceMock, false, flowLogger, iface.DefaultMTU)
+	manager, err := Create(ifaceMock, false, flowLogger)
 	require.NoError(tb, err)
 	require.NoError(tb, manager.EnableRouting())
 	require.NotNil(tb, manager)
@@ -1463,7 +1439,7 @@ func TestRouteACLSet(t *testing.T) {
 		},
 	}
 
-	manager, err := Create(ifaceMock, false, flowLogger, iface.DefaultMTU)
+	manager, err := Create(ifaceMock, false, flowLogger)
 	require.NoError(t, err)
 	t.Cleanup(func() {
 		require.NoError(t, manager.Close(nil))

client/firewall/uspfilter/filter_test.go

@@ -1,7 +1,6 @@
 package uspfilter
 
 import (
-	"encoding/binary"
 	"fmt"
 	"net"
 	"net/netip"
@@ -18,7 +17,6 @@ import (
 	fw "github.com/netbirdio/netbird/client/firewall/manager"
 	"github.com/netbirdio/netbird/client/firewall/uspfilter/conntrack"
 	"github.com/netbirdio/netbird/client/firewall/uspfilter/log"
-	nbiface "github.com/netbirdio/netbird/client/iface"
 	"github.com/netbirdio/netbird/client/iface/device"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
 	"github.com/netbirdio/netbird/client/internal/netflow"
@@ -68,7 +66,7 @@ func TestManagerCreate(t *testing.T) {
 		SetFilterFunc: func(device.PacketFilter) error { return nil },
 	}
 
-	m, err := Create(ifaceMock, false, flowLogger, nbiface.DefaultMTU)
+	m, err := Create(ifaceMock, false, flowLogger)
 	if err != nil {
 		t.Errorf("failed to create Manager: %v", err)
 		return
@@ -88,7 +86,7 @@ func TestManagerAddPeerFiltering(t *testing.T) {
 		},
 	}
 
-	m, err := Create(ifaceMock, false, flowLogger, nbiface.DefaultMTU)
+	m, err := Create(ifaceMock, false, flowLogger)
 	if err != nil {
 		t.Errorf("failed to create Manager: %v", err)
 		return
@@ -121,7 +119,7 @@ func TestManagerDeleteRule(t *testing.T) {
 		SetFilterFunc: func(device.PacketFilter) error { return nil },
 	}
 
-	m, err := Create(ifaceMock, false, flowLogger, nbiface.DefaultMTU)
+	m, err := Create(ifaceMock, false, flowLogger)
 	if err != nil {
 		t.Errorf("failed to create Manager: %v", err)
 		return
@@ -138,22 +136,9 @@ func TestManagerDeleteRule(t *testing.T) {
 		return
 	}
 
-	// Check rules exist in appropriate maps
 	for _, r := range rule2 {
-		peerRule, ok := r.(*PeerRule)
-		if !ok {
-			t.Errorf("rule should be a PeerRule")
-			continue
-		}
-		// Check if rule exists in deny or allow maps based on action
-		var found bool
-		if peerRule.drop {
-			_, found = m.incomingDenyRules[ip][r.ID()]
-		} else {
-			_, found = m.incomingRules[ip][r.ID()]
-		}
-		if !found {
-			t.Errorf("rule2 is not in the expected rules map")
+		if _, ok := m.incomingRules[ip][r.ID()]; !ok {
+			t.Errorf("rule2 is not in the incomingRules")
 		}
 	}
 
@@ -165,22 +150,9 @@ func TestManagerDeleteRule(t *testing.T) {
 		}
 	}
 
-	// Check rules are removed from appropriate maps
 	for _, r := range rule2 {
-		peerRule, ok := r.(*PeerRule)
-		if !ok {
-			t.Errorf("rule should be a PeerRule")
-			continue
-		}
-		// Check if rule is removed from deny or allow maps based on action
-		var found bool
-		if peerRule.drop {
-			_, found = m.incomingDenyRules[ip][r.ID()]
-		} else {
-			_, found = m.incomingRules[ip][r.ID()]
-		}
-		if found {
-			t.Errorf("rule2 should be removed from the rules map")
+		if _, ok := m.incomingRules[ip][r.ID()]; ok {
+			t.Errorf("rule2 is not in the incomingRules")
 		}
 	}
 }
@@ -217,24 +189,23 @@ func TestAddUDPPacketHook(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			manager, err := Create(&IFaceMock{
 				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false, flowLogger, nbiface.DefaultMTU)
+			}, false, flowLogger)
 			require.NoError(t, err)
 
 			manager.AddUDPPacketHook(tt.in, tt.ip, tt.dPort, tt.hook)
 
 			var addedRule PeerRule
 			if tt.in {
-				// Incoming UDP hooks are stored in allow rules map
 				if len(manager.incomingRules[tt.ip]) != 1 {
-					t.Errorf("expected 1 incoming rule, got %d", len(manager.incomingRules[tt.ip]))
+					t.Errorf("expected 1 incoming rule, got %d", len(manager.incomingRules))
 					return
 				}
 				for _, rule := range manager.incomingRules[tt.ip] {
 					addedRule = rule
 				}
 			} else {
-				if len(manager.outgoingRules[tt.ip]) != 1 {
-					t.Errorf("expected 1 outgoing rule, got %d", len(manager.outgoingRules[tt.ip]))
+				if len(manager.outgoingRules) != 1 {
+					t.Errorf("expected 1 outgoing rule, got %d", len(manager.outgoingRules))
 					return
 				}
 				for _, rule := range manager.outgoingRules[tt.ip] {
@@ -267,7 +238,7 @@ func TestManagerReset(t *testing.T) {
 		SetFilterFunc: func(device.PacketFilter) error { return nil },
 	}
 
-	m, err := Create(ifaceMock, false, flowLogger, nbiface.DefaultMTU)
+	m, err := Create(ifaceMock, false, flowLogger)
 	if err != nil {
 		t.Errorf("failed to create Manager: %v", err)
 		return
@@ -290,8 +261,8 @@ func TestManagerReset(t *testing.T) {
 		return
 	}
 
-	if len(m.outgoingRules) != 0 || len(m.incomingRules) != 0 || len(m.incomingDenyRules) != 0 {
-		t.Errorf("rules are not empty")
+	if len(m.outgoingRules) != 0 || len(m.incomingRules) != 0 {
+		t.Errorf("rules is not empty")
 	}
 }
 
@@ -306,7 +277,7 @@ func TestNotMatchByIP(t *testing.T) {
 		},
 	}
 
-	m, err := Create(ifaceMock, false, flowLogger, nbiface.DefaultMTU)
+	m, err := Create(ifaceMock, false, flowLogger)
 	if err != nil {
 		t.Errorf("failed to create Manager: %v", err)
 		return
@@ -369,7 +340,7 @@ func TestRemovePacketHook(t *testing.T) {
 	}
 
 	// creating manager instance
-	manager, err := Create(iface, false, flowLogger, nbiface.DefaultMTU)
+	manager, err := Create(iface, false, flowLogger)
 	if err != nil {
 		t.Fatalf("Failed to create Manager: %s", err)
 	}
@@ -415,7 +386,7 @@ func TestRemovePacketHook(t *testing.T) {
 func TestProcessOutgoingHooks(t *testing.T) {
 	manager, err := Create(&IFaceMock{
 		SetFilterFunc: func(device.PacketFilter) error { return nil },
-	}, false, flowLogger, nbiface.DefaultMTU)
+	}, false, flowLogger)
 	require.NoError(t, err)
 
 	manager.udpTracker.Close()
@@ -497,7 +468,7 @@ func TestUSPFilterCreatePerformance(t *testing.T) {
 			ifaceMock := &IFaceMock{
 				SetFilterFunc: func(device.PacketFilter) error { return nil },
 			}
-			manager, err := Create(ifaceMock, false, flowLogger, nbiface.DefaultMTU)
+			manager, err := Create(ifaceMock, false, flowLogger)
 			require.NoError(t, err)
 			time.Sleep(time.Second)
 
@@ -524,7 +495,7 @@ func TestUSPFilterCreatePerformance(t *testing.T) {
 func TestStatefulFirewall_UDPTracking(t *testing.T) {
 	manager, err := Create(&IFaceMock{
 		SetFilterFunc: func(device.PacketFilter) error { return nil },
-	}, false, flowLogger, nbiface.DefaultMTU)
+	}, false, flowLogger)
 	require.NoError(t, err)
 
 	manager.udpTracker.Close() // Close the existing tracker
@@ -731,7 +702,7 @@ func TestUpdateSetMerge(t *testing.T) {
 		SetFilterFunc: func(device.PacketFilter) error { return nil },
 	}
 
-	manager, err := Create(ifaceMock, false, flowLogger, nbiface.DefaultMTU)
+	manager, err := Create(ifaceMock, false, flowLogger)
 	require.NoError(t, err)
 	t.Cleanup(func() {
 		require.NoError(t, manager.Close(nil))
@@ -817,7 +788,7 @@ func TestUpdateSetDeduplication(t *testing.T) {
 		SetFilterFunc: func(device.PacketFilter) error { return nil },
 	}
 
-	manager, err := Create(ifaceMock, false, flowLogger, nbiface.DefaultMTU)
+	manager, err := Create(ifaceMock, false, flowLogger)
 	require.NoError(t, err)
 	t.Cleanup(func() {
 		require.NoError(t, manager.Close(nil))
@@ -925,192 +896,3 @@ func TestUpdateSetDeduplication(t *testing.T) {
 		require.Equal(t, tc.expected, isAllowed, tc.desc)
 	}
 }
-
-func TestMSSClamping(t *testing.T) {
-	ifaceMock := &IFaceMock{
-		SetFilterFunc: func(device.PacketFilter) error { return nil },
-		AddressFunc: func() wgaddr.Address {
-			return wgaddr.Address{
-				IP:      netip.MustParseAddr("100.10.0.100"),
-				Network: netip.MustParsePrefix("100.10.0.0/16"),
-			}
-		},
-	}
-
-	manager, err := Create(ifaceMock, false, flowLogger, 1280)
-	require.NoError(t, err)
-	defer func() {
-		require.NoError(t, manager.Close(nil))
-	}()
-
-	require.True(t, manager.mssClampEnabled, "MSS clamping should be enabled by default")
-	expectedMSSValue := uint16(1280 - ipTCPHeaderMinSize)
-	require.Equal(t, expectedMSSValue, manager.mssClampValue, "MSS clamp value should be MTU - 40")
-
-	err = manager.UpdateLocalIPs()
-	require.NoError(t, err)
-
-	srcIP := net.ParseIP("100.10.0.2")
-	dstIP := net.ParseIP("8.8.8.8")
-
-	t.Run("SYN packet with high MSS gets clamped", func(t *testing.T) {
-		highMSS := uint16(1460)
-		packet := generateSYNPacketWithMSS(t, srcIP, dstIP, 12345, 80, highMSS)
-
-		manager.filterOutbound(packet, len(packet))
-
-		d := parsePacket(t, packet)
-		require.Len(t, d.tcp.Options, 1, "Should have MSS option")
-		require.Equal(t, uint8(layers.TCPOptionKindMSS), uint8(d.tcp.Options[0].OptionType))
-		actualMSS := binary.BigEndian.Uint16(d.tcp.Options[0].OptionData)
-		require.Equal(t, expectedMSSValue, actualMSS, "MSS should be clamped to MTU - 40")
-	})
-
-	t.Run("SYN packet with low MSS unchanged", func(t *testing.T) {
-		lowMSS := uint16(1200)
-		packet := generateSYNPacketWithMSS(t, srcIP, dstIP, 12345, 80, lowMSS)
-
-		manager.filterOutbound(packet, len(packet))
-
-		d := parsePacket(t, packet)
-		require.Len(t, d.tcp.Options, 1, "Should have MSS option")
-		actualMSS := binary.BigEndian.Uint16(d.tcp.Options[0].OptionData)
-		require.Equal(t, lowMSS, actualMSS, "Low MSS should not be modified")
-	})
-
-	t.Run("SYN-ACK packet gets clamped", func(t *testing.T) {
-		highMSS := uint16(1460)
-		packet := generateSYNACKPacketWithMSS(t, srcIP, dstIP, 12345, 80, highMSS)
-
-		manager.filterOutbound(packet, len(packet))
-
-		d := parsePacket(t, packet)
-		require.Len(t, d.tcp.Options, 1, "Should have MSS option")
-		actualMSS := binary.BigEndian.Uint16(d.tcp.Options[0].OptionData)
-		require.Equal(t, expectedMSSValue, actualMSS, "MSS in SYN-ACK should be clamped")
-	})
-
-	t.Run("Non-SYN packet unchanged", func(t *testing.T) {
-		packet := generateTCPPacketWithFlags(t, srcIP, dstIP, 12345, 80, uint16(conntrack.TCPAck))
-
-		manager.filterOutbound(packet, len(packet))
-
-		d := parsePacket(t, packet)
-		require.Empty(t, d.tcp.Options, "ACK packet should have no options")
-	})
-}
-
-func generateSYNPacketWithMSS(tb testing.TB, srcIP, dstIP net.IP, srcPort, dstPort uint16, mss uint16) []byte {
-	tb.Helper()
-
-	ipLayer := &layers.IPv4{
-		Version:  4,
-		TTL:      64,
-		Protocol: layers.IPProtocolTCP,
-		SrcIP:    srcIP,
-		DstIP:    dstIP,
-	}
-
-	tcpLayer := &layers.TCP{
-		SrcPort: layers.TCPPort(srcPort),
-		DstPort: layers.TCPPort(dstPort),
-		SYN:     true,
-		Window:  65535,
-		Options: []layers.TCPOption{
-			{
-				OptionType:   layers.TCPOptionKindMSS,
-				OptionLength: 4,
-				OptionData:   binary.BigEndian.AppendUint16(nil, mss),
-			},
-		},
-	}
-	err := tcpLayer.SetNetworkLayerForChecksum(ipLayer)
-	require.NoError(tb, err)
-
-	buf := gopacket.NewSerializeBuffer()
-	opts := gopacket.SerializeOptions{ComputeChecksums: true, FixLengths: true}
-	err = gopacket.SerializeLayers(buf, opts, ipLayer, tcpLayer, gopacket.Payload([]byte{}))
-	require.NoError(tb, err)
-
-	return buf.Bytes()
-}
-
-func generateSYNACKPacketWithMSS(tb testing.TB, srcIP, dstIP net.IP, srcPort, dstPort uint16, mss uint16) []byte {
-	tb.Helper()
-
-	ipLayer := &layers.IPv4{
-		Version:  4,
-		TTL:      64,
-		Protocol: layers.IPProtocolTCP,
-		SrcIP:    srcIP,
-		DstIP:    dstIP,
-	}
-
-	tcpLayer := &layers.TCP{
-		SrcPort: layers.TCPPort(srcPort),
-		DstPort: layers.TCPPort(dstPort),
-		SYN:     true,
-		ACK:     true,
-		Window:  65535,
-		Options: []layers.TCPOption{
-			{
-				OptionType:   layers.TCPOptionKindMSS,
-				OptionLength: 4,
-				OptionData:   binary.BigEndian.AppendUint16(nil, mss),
-			},
-		},
-	}
-	err := tcpLayer.SetNetworkLayerForChecksum(ipLayer)
-	require.NoError(tb, err)
-
-	buf := gopacket.NewSerializeBuffer()
-	opts := gopacket.SerializeOptions{ComputeChecksums: true, FixLengths: true}
-	err = gopacket.SerializeLayers(buf, opts, ipLayer, tcpLayer, gopacket.Payload([]byte{}))
-	require.NoError(tb, err)
-
-	return buf.Bytes()
-}
-
-func generateTCPPacketWithFlags(tb testing.TB, srcIP, dstIP net.IP, srcPort, dstPort uint16, flags uint16) []byte {
-	tb.Helper()
-
-	ipLayer := &layers.IPv4{
-		Version:  4,
-		TTL:      64,
-		Protocol: layers.IPProtocolTCP,
-		SrcIP:    srcIP,
-		DstIP:    dstIP,
-	}
-
-	tcpLayer := &layers.TCP{
-		SrcPort: layers.TCPPort(srcPort),
-		DstPort: layers.TCPPort(dstPort),
-		Window:  65535,
-	}
-
-	if flags&uint16(conntrack.TCPSyn) != 0 {
-		tcpLayer.SYN = true
-	}
-	if flags&uint16(conntrack.TCPAck) != 0 {
-		tcpLayer.ACK = true
-	}
-	if flags&uint16(conntrack.TCPFin) != 0 {
-		tcpLayer.FIN = true
-	}
-	if flags&uint16(conntrack.TCPRst) != 0 {
-		tcpLayer.RST = true
-	}
-	if flags&uint16(conntrack.TCPPush) != 0 {
-		tcpLayer.PSH = true
-	}
-
-	err := tcpLayer.SetNetworkLayerForChecksum(ipLayer)
-	require.NoError(tb, err)
-
-	buf := gopacket.NewSerializeBuffer()
-	opts := gopacket.SerializeOptions{ComputeChecksums: true, FixLengths: true}
-	err = gopacket.SerializeLayers(buf, opts, ipLayer, tcpLayer, gopacket.Payload([]byte{}))
-	require.NoError(tb, err)
-
-	return buf.Bytes()
-}

client/firewall/uspfilter/forwarder/forwarder.go

@@ -45,7 +45,7 @@ type Forwarder struct {
 	netstack     bool
 }
 
-func New(iface common.IFaceMapper, logger *nblog.Logger, flowLogger nftypes.FlowLogger, netstack bool, mtu uint16) (*Forwarder, error) {
+func New(iface common.IFaceMapper, logger *nblog.Logger, flowLogger nftypes.FlowLogger, netstack bool) (*Forwarder, error) {
 	s := stack.New(stack.Options{
 		NetworkProtocols: []stack.NetworkProtocolFactory{ipv4.NewProtocol},
 		TransportProtocols: []stack.TransportProtocolFactory{
@@ -56,6 +56,10 @@ func New(iface common.IFaceMapper, logger *nblog.Logger, flowLogger nftypes.Flow
 		HandleLocal: false,
 	})
 
+	mtu, err := iface.GetDevice().MTU()
+	if err != nil {
+		return nil, fmt.Errorf("get MTU: %w", err)
+	}
 	nicID := tcpip.NICID(1)
 	endpoint := &endpoint{
 		logger: logger,
@@ -64,7 +68,7 @@ func New(iface common.IFaceMapper, logger *nblog.Logger, flowLogger nftypes.Flow
 	}
 
 	if err := s.CreateNIC(nicID, endpoint); err != nil {
-		return nil, fmt.Errorf("create NIC: %v", err)
+		return nil, fmt.Errorf("failed to create NIC: %v", err)
 	}
 
 	protoAddr := tcpip.ProtocolAddress{

client/firewall/uspfilter/forwarder/udp.go

@@ -49,7 +49,7 @@ type idleConn struct {
 	conn *udpPacketConn
 }
 
-func newUDPForwarder(mtu uint16, logger *nblog.Logger, flowLogger nftypes.FlowLogger) *udpForwarder {
+func newUDPForwarder(mtu int, logger *nblog.Logger, flowLogger nftypes.FlowLogger) *udpForwarder {
 	ctx, cancel := context.WithCancel(context.Background())
 	f := &udpForwarder{
 		logger:     logger,

client/firewall/uspfilter/log/log.go

@@ -50,8 +50,6 @@ type logMessage struct {
 	arg4   any
 	arg5   any
 	arg6   any
-	arg7   any
-	arg8   any
 }
 
 // Logger is a high-performance, non-blocking logger
@@ -96,6 +94,7 @@ func (l *Logger) SetLevel(level Level) {
 	log.Debugf("Set uspfilter logger loglevel to %v", levelStrings[level])
 }
 
+
 func (l *Logger) Error(format string) {
 	if l.level.Load() >= uint32(LevelError) {
 		select {
@@ -186,15 +185,6 @@ func (l *Logger) Debug2(format string, arg1, arg2 any) {
 	}
 }
 
-func (l *Logger) Debug3(format string, arg1, arg2, arg3 any) {
-	if l.level.Load() >= uint32(LevelDebug) {
-		select {
-		case l.msgChannel <- logMessage{level: LevelDebug, format: format, arg1: arg1, arg2: arg2, arg3: arg3}:
-		default:
-		}
-	}
-}
-
 func (l *Logger) Trace1(format string, arg1 any) {
 	if l.level.Load() >= uint32(LevelTrace) {
 		select {
@@ -249,16 +239,6 @@ func (l *Logger) Trace6(format string, arg1, arg2, arg3, arg4, arg5, arg6 any) {
 	}
 }
 
-// Trace8 logs a trace message with 8 arguments (8 placeholder in format string)
-func (l *Logger) Trace8(format string, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8 any) {
-	if l.level.Load() >= uint32(LevelTrace) {
-		select {
-		case l.msgChannel <- logMessage{level: LevelTrace, format: format, arg1: arg1, arg2: arg2, arg3: arg3, arg4: arg4, arg5: arg5, arg6: arg6, arg7: arg7, arg8: arg8}:
-		default:
-		}
-	}
-}
-
 func (l *Logger) formatMessage(buf *[]byte, msg logMessage) {
 	*buf = (*buf)[:0]
 	*buf = time.Now().AppendFormat(*buf, "2006-01-02T15:04:05-07:00")
@@ -280,12 +260,6 @@ func (l *Logger) formatMessage(buf *[]byte, msg logMessage) {
 						argCount++
 						if msg.arg6 != nil {
 							argCount++
-							if msg.arg7 != nil {
-								argCount++
-								if msg.arg8 != nil {
-									argCount++
-								}
-							}
 						}
 					}
 				}
@@ -309,10 +283,6 @@ func (l *Logger) formatMessage(buf *[]byte, msg logMessage) {
 		formatted = fmt.Sprintf(msg.format, msg.arg1, msg.arg2, msg.arg3, msg.arg4, msg.arg5)
 	case 6:
 		formatted = fmt.Sprintf(msg.format, msg.arg1, msg.arg2, msg.arg3, msg.arg4, msg.arg5, msg.arg6)
-	case 7:
-		formatted = fmt.Sprintf(msg.format, msg.arg1, msg.arg2, msg.arg3, msg.arg4, msg.arg5, msg.arg6, msg.arg7)
-	case 8:
-		formatted = fmt.Sprintf(msg.format, msg.arg1, msg.arg2, msg.arg3, msg.arg4, msg.arg5, msg.arg6, msg.arg7, msg.arg8)
 	}
 
 	*buf = append(*buf, formatted...)
@@ -420,4 +390,4 @@ func (l *Logger) Stop(ctx context.Context) error {
 	case <-done:
 		return nil
 	}
-}
+}

client/firewall/uspfilter/nat.go

@@ -5,9 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"net/netip"
-	"slices"
 
-	"github.com/google/gopacket"
 	"github.com/google/gopacket/layers"
 
 	firewall "github.com/netbirdio/netbird/client/firewall/manager"
@@ -15,21 +13,6 @@ import (
 
 var ErrIPv4Only = errors.New("only IPv4 is supported for DNAT")
 
-var (
-	errInvalidIPHeaderLength = errors.New("invalid IP header length")
-)
-
-const (
-	// Port offsets in TCP/UDP headers
-	sourcePortOffset      = 0
-	destinationPortOffset = 2
-
-	// IP address offsets in IPv4 header
-	sourceIPOffset      = 12
-	destinationIPOffset = 16
-)
-
-// ipv4Checksum calculates IPv4 header checksum.
 func ipv4Checksum(header []byte) uint16 {
 	if len(header) < 20 {
 		return 0
@@ -69,7 +52,6 @@ func ipv4Checksum(header []byte) uint16 {
 	return ^uint16(sum)
 }
 
-// icmpChecksum calculates ICMP checksum.
 func icmpChecksum(data []byte) uint16 {
 	var sum1, sum2, sum3, sum4 uint32
 	i := 0
@@ -107,21 +89,11 @@ func icmpChecksum(data []byte) uint16 {
 	return ^uint16(sum)
 }
 
-// biDNATMap maintains bidirectional DNAT mappings.
 type biDNATMap struct {
 	forward map[netip.Addr]netip.Addr
 	reverse map[netip.Addr]netip.Addr
 }
 
-// portDNATRule represents a port-specific DNAT rule.
-type portDNATRule struct {
-	protocol   gopacket.LayerType
-	origPort   uint16
-	targetPort uint16
-	targetIP   netip.Addr
-}
-
-// newBiDNATMap creates a new bidirectional DNAT mapping structure.
 func newBiDNATMap() *biDNATMap {
 	return &biDNATMap{
 		forward: make(map[netip.Addr]netip.Addr),
@@ -129,13 +101,11 @@ func newBiDNATMap() *biDNATMap {
 	}
 }
 
-// set adds a bidirectional DNAT mapping between original and translated addresses.
 func (b *biDNATMap) set(original, translated netip.Addr) {
 	b.forward[original] = translated
 	b.reverse[translated] = original
 }
 
-// delete removes a bidirectional DNAT mapping for the given original address.
 func (b *biDNATMap) delete(original netip.Addr) {
 	if translated, exists := b.forward[original]; exists {
 		delete(b.forward, original)
@@ -143,25 +113,19 @@ func (b *biDNATMap) delete(original netip.Addr) {
 	}
 }
 
-// getTranslated returns the translated address for a given original address.
 func (b *biDNATMap) getTranslated(original netip.Addr) (netip.Addr, bool) {
 	translated, exists := b.forward[original]
 	return translated, exists
 }
 
-// getOriginal returns the original address for a given translated address.
 func (b *biDNATMap) getOriginal(translated netip.Addr) (netip.Addr, bool) {
 	original, exists := b.reverse[translated]
 	return original, exists
 }
 
-// AddInternalDNATMapping adds a 1:1 IP address mapping for internal DNAT translation.
 func (m *Manager) AddInternalDNATMapping(originalAddr, translatedAddr netip.Addr) error {
-	if !originalAddr.IsValid() {
-		return fmt.Errorf("invalid original IP address")
-	}
-	if !translatedAddr.IsValid() {
-		return fmt.Errorf("invalid translated IP address")
+	if !originalAddr.IsValid() || !translatedAddr.IsValid() {
+		return fmt.Errorf("invalid IP addresses")
 	}
 
 	if m.localipmanager.IsLocalIP(translatedAddr) {
@@ -171,6 +135,7 @@ func (m *Manager) AddInternalDNATMapping(originalAddr, translatedAddr netip.Addr
 	m.dnatMutex.Lock()
 	defer m.dnatMutex.Unlock()
 
+	// Initialize both maps together if either is nil
 	if m.dnatMappings == nil || m.dnatBiMap == nil {
 		m.dnatMappings = make(map[netip.Addr]netip.Addr)
 		m.dnatBiMap = newBiDNATMap()
@@ -186,7 +151,7 @@ func (m *Manager) AddInternalDNATMapping(originalAddr, translatedAddr netip.Addr
 	return nil
 }
 
-// RemoveInternalDNATMapping removes a 1:1 IP address mapping.
+// RemoveInternalDNATMapping removes a 1:1 IP address mapping
 func (m *Manager) RemoveInternalDNATMapping(originalAddr netip.Addr) error {
 	m.dnatMutex.Lock()
 	defer m.dnatMutex.Unlock()
@@ -204,7 +169,7 @@ func (m *Manager) RemoveInternalDNATMapping(originalAddr netip.Addr) error {
 	return nil
 }
 
-// getDNATTranslation returns the translated address if a mapping exists.
+// getDNATTranslation returns the translated address if a mapping exists
 func (m *Manager) getDNATTranslation(addr netip.Addr) (netip.Addr, bool) {
 	if !m.dnatEnabled.Load() {
 		return addr, false
@@ -216,7 +181,7 @@ func (m *Manager) getDNATTranslation(addr netip.Addr) (netip.Addr, bool) {
 	return translated, exists
 }
 
-// findReverseDNATMapping finds original address for return traffic.
+// findReverseDNATMapping finds original address for return traffic
 func (m *Manager) findReverseDNATMapping(translatedAddr netip.Addr) (netip.Addr, bool) {
 	if !m.dnatEnabled.Load() {
 		return translatedAddr, false
@@ -228,12 +193,16 @@ func (m *Manager) findReverseDNATMapping(translatedAddr netip.Addr) (netip.Addr,
 	return original, exists
 }
 
-// translateOutboundDNAT applies DNAT translation to outbound packets.
+// translateOutboundDNAT applies DNAT translation to outbound packets
 func (m *Manager) translateOutboundDNAT(packetData []byte, d *decoder) bool {
 	if !m.dnatEnabled.Load() {
 		return false
 	}
 
+	if len(packetData) < 20 || d.decoded[0] != layers.LayerTypeIPv4 {
+		return false
+	}
+
 	dstIP := netip.AddrFrom4([4]byte{packetData[16], packetData[17], packetData[18], packetData[19]})
 
 	translatedIP, exists := m.getDNATTranslation(dstIP)
@@ -241,8 +210,8 @@ func (m *Manager) translateOutboundDNAT(packetData []byte, d *decoder) bool {
 		return false
 	}
 
-	if err := m.rewritePacketIP(packetData, d, translatedIP, destinationIPOffset); err != nil {
-		m.logger.Error1("failed to rewrite packet destination: %v", err)
+	if err := m.rewritePacketDestination(packetData, d, translatedIP); err != nil {
+		m.logger.Error1("Failed to rewrite packet destination: %v", err)
 		return false
 	}
 
@@ -250,12 +219,16 @@ func (m *Manager) translateOutboundDNAT(packetData []byte, d *decoder) bool {
 	return true
 }
 
-// translateInboundReverse applies reverse DNAT to inbound return traffic.
+// translateInboundReverse applies reverse DNAT to inbound return traffic
 func (m *Manager) translateInboundReverse(packetData []byte, d *decoder) bool {
 	if !m.dnatEnabled.Load() {
 		return false
 	}
 
+	if len(packetData) < 20 || d.decoded[0] != layers.LayerTypeIPv4 {
+		return false
+	}
+
 	srcIP := netip.AddrFrom4([4]byte{packetData[12], packetData[13], packetData[14], packetData[15]})
 
 	originalIP, exists := m.findReverseDNATMapping(srcIP)
@@ -263,8 +236,8 @@ func (m *Manager) translateInboundReverse(packetData []byte, d *decoder) bool {
 		return false
 	}
 
-	if err := m.rewritePacketIP(packetData, d, originalIP, sourceIPOffset); err != nil {
-		m.logger.Error1("failed to rewrite packet source: %v", err)
+	if err := m.rewritePacketSource(packetData, d, originalIP); err != nil {
+		m.logger.Error1("Failed to rewrite packet source: %v", err)
 		return false
 	}
 
@@ -272,21 +245,21 @@ func (m *Manager) translateInboundReverse(packetData []byte, d *decoder) bool {
 	return true
 }
 
-// rewritePacketIP replaces an IP address (source or destination) in the packet and updates checksums.
-func (m *Manager) rewritePacketIP(packetData []byte, d *decoder, newIP netip.Addr, ipOffset int) error {
-	if !newIP.Is4() {
+// rewritePacketDestination replaces destination IP in the packet
+func (m *Manager) rewritePacketDestination(packetData []byte, d *decoder, newIP netip.Addr) error {
+	if len(packetData) < 20 || d.decoded[0] != layers.LayerTypeIPv4 || !newIP.Is4() {
 		return ErrIPv4Only
 	}
 
-	var oldIP [4]byte
-	copy(oldIP[:], packetData[ipOffset:ipOffset+4])
-	newIPBytes := newIP.As4()
+	var oldDst [4]byte
+	copy(oldDst[:], packetData[16:20])
+	newDst := newIP.As4()
 
-	copy(packetData[ipOffset:ipOffset+4], newIPBytes[:])
+	copy(packetData[16:20], newDst[:])
 
 	ipHeaderLen := int(d.ip4.IHL) * 4
 	if ipHeaderLen < 20 || ipHeaderLen > len(packetData) {
-		return errInvalidIPHeaderLength
+		return fmt.Errorf("invalid IP header length")
 	}
 
 	binary.BigEndian.PutUint16(packetData[10:12], 0)
@@ -296,9 +269,44 @@ func (m *Manager) rewritePacketIP(packetData []byte, d *decoder, newIP netip.Add
 	if len(d.decoded) > 1 {
 		switch d.decoded[1] {
 		case layers.LayerTypeTCP:
-			m.updateTCPChecksum(packetData, ipHeaderLen, oldIP[:], newIPBytes[:])
+			m.updateTCPChecksum(packetData, ipHeaderLen, oldDst[:], newDst[:])
 		case layers.LayerTypeUDP:
-			m.updateUDPChecksum(packetData, ipHeaderLen, oldIP[:], newIPBytes[:])
+			m.updateUDPChecksum(packetData, ipHeaderLen, oldDst[:], newDst[:])
+		case layers.LayerTypeICMPv4:
+			m.updateICMPChecksum(packetData, ipHeaderLen)
+		}
+	}
+
+	return nil
+}
+
+// rewritePacketSource replaces the source IP address in the packet
+func (m *Manager) rewritePacketSource(packetData []byte, d *decoder, newIP netip.Addr) error {
+	if len(packetData) < 20 || d.decoded[0] != layers.LayerTypeIPv4 || !newIP.Is4() {
+		return ErrIPv4Only
+	}
+
+	var oldSrc [4]byte
+	copy(oldSrc[:], packetData[12:16])
+	newSrc := newIP.As4()
+
+	copy(packetData[12:16], newSrc[:])
+
+	ipHeaderLen := int(d.ip4.IHL) * 4
+	if ipHeaderLen < 20 || ipHeaderLen > len(packetData) {
+		return fmt.Errorf("invalid IP header length")
+	}
+
+	binary.BigEndian.PutUint16(packetData[10:12], 0)
+	ipChecksum := ipv4Checksum(packetData[:ipHeaderLen])
+	binary.BigEndian.PutUint16(packetData[10:12], ipChecksum)
+
+	if len(d.decoded) > 1 {
+		switch d.decoded[1] {
+		case layers.LayerTypeTCP:
+			m.updateTCPChecksum(packetData, ipHeaderLen, oldSrc[:], newSrc[:])
+		case layers.LayerTypeUDP:
+			m.updateUDPChecksum(packetData, ipHeaderLen, oldSrc[:], newSrc[:])
 		case layers.LayerTypeICMPv4:
 			m.updateICMPChecksum(packetData, ipHeaderLen)
 		}
@@ -307,7 +315,6 @@ func (m *Manager) rewritePacketIP(packetData []byte, d *decoder, newIP netip.Add
 	return nil
 }
 
-// updateTCPChecksum updates TCP checksum after IP address change per RFC 1624.
 func (m *Manager) updateTCPChecksum(packetData []byte, ipHeaderLen int, oldIP, newIP []byte) {
 	tcpStart := ipHeaderLen
 	if len(packetData) < tcpStart+18 {
@@ -320,7 +327,6 @@ func (m *Manager) updateTCPChecksum(packetData []byte, ipHeaderLen int, oldIP, n
 	binary.BigEndian.PutUint16(packetData[checksumOffset:checksumOffset+2], newChecksum)
 }
 
-// updateUDPChecksum updates UDP checksum after IP address change per RFC 1624.
 func (m *Manager) updateUDPChecksum(packetData []byte, ipHeaderLen int, oldIP, newIP []byte) {
 	udpStart := ipHeaderLen
 	if len(packetData) < udpStart+8 {
@@ -338,7 +344,6 @@ func (m *Manager) updateUDPChecksum(packetData []byte, ipHeaderLen int, oldIP, n
 	binary.BigEndian.PutUint16(packetData[checksumOffset:checksumOffset+2], newChecksum)
 }
 
-// updateICMPChecksum recalculates ICMP checksum after packet modification.
 func (m *Manager) updateICMPChecksum(packetData []byte, ipHeaderLen int) {
 	icmpStart := ipHeaderLen
 	if len(packetData) < icmpStart+8 {
@@ -351,7 +356,7 @@ func (m *Manager) updateICMPChecksum(packetData []byte, ipHeaderLen int) {
 	binary.BigEndian.PutUint16(icmpData[2:4], checksum)
 }
 
-// incrementalUpdate performs incremental checksum update per RFC 1624.
+// incrementalUpdate performs incremental checksum update per RFC 1624
 func incrementalUpdate(oldChecksum uint16, oldBytes, newBytes []byte) uint16 {
 	sum := uint32(^oldChecksum)
 
@@ -386,7 +391,7 @@ func incrementalUpdate(oldChecksum uint16, oldBytes, newBytes []byte) uint16 {
 	return ^uint16(sum)
 }
 
-// AddDNATRule adds outbound DNAT rule for forwarding external traffic to NetBird network.
+// AddDNATRule adds a DNAT rule (delegates to native firewall for port forwarding)
 func (m *Manager) AddDNATRule(rule firewall.ForwardRule) (firewall.Rule, error) {
 	if m.nativeFirewall == nil {
 		return nil, errNatNotSupported
@@ -394,184 +399,10 @@ func (m *Manager) AddDNATRule(rule firewall.ForwardRule) (firewall.Rule, error)
 	return m.nativeFirewall.AddDNATRule(rule)
 }
 
-// DeleteDNATRule deletes outbound DNAT rule.
+// DeleteDNATRule deletes a DNAT rule (delegates to native firewall)
 func (m *Manager) DeleteDNATRule(rule firewall.Rule) error {
 	if m.nativeFirewall == nil {
 		return errNatNotSupported
 	}
 	return m.nativeFirewall.DeleteDNATRule(rule)
 }
-
-// addPortRedirection adds a port redirection rule.
-func (m *Manager) addPortRedirection(targetIP netip.Addr, protocol gopacket.LayerType, sourcePort, targetPort uint16) error {
-	m.portDNATMutex.Lock()
-	defer m.portDNATMutex.Unlock()
-
-	rule := portDNATRule{
-		protocol:   protocol,
-		origPort:   sourcePort,
-		targetPort: targetPort,
-		targetIP:   targetIP,
-	}
-
-	m.portDNATRules = append(m.portDNATRules, rule)
-	m.portDNATEnabled.Store(true)
-
-	return nil
-}
-
-// AddInboundDNAT adds an inbound DNAT rule redirecting traffic from NetBird peers to local services.
-func (m *Manager) AddInboundDNAT(localAddr netip.Addr, protocol firewall.Protocol, sourcePort, targetPort uint16) error {
-	var layerType gopacket.LayerType
-	switch protocol {
-	case firewall.ProtocolTCP:
-		layerType = layers.LayerTypeTCP
-	case firewall.ProtocolUDP:
-		layerType = layers.LayerTypeUDP
-	default:
-		return fmt.Errorf("unsupported protocol: %s", protocol)
-	}
-
-	return m.addPortRedirection(localAddr, layerType, sourcePort, targetPort)
-}
-
-// removePortRedirection removes a port redirection rule.
-func (m *Manager) removePortRedirection(targetIP netip.Addr, protocol gopacket.LayerType, sourcePort, targetPort uint16) error {
-	m.portDNATMutex.Lock()
-	defer m.portDNATMutex.Unlock()
-
-	m.portDNATRules = slices.DeleteFunc(m.portDNATRules, func(rule portDNATRule) bool {
-		return rule.protocol == protocol && rule.origPort == sourcePort && rule.targetPort == targetPort && rule.targetIP.Compare(targetIP) == 0
-	})
-
-	if len(m.portDNATRules) == 0 {
-		m.portDNATEnabled.Store(false)
-	}
-
-	return nil
-}
-
-// RemoveInboundDNAT removes an inbound DNAT rule.
-func (m *Manager) RemoveInboundDNAT(localAddr netip.Addr, protocol firewall.Protocol, sourcePort, targetPort uint16) error {
-	var layerType gopacket.LayerType
-	switch protocol {
-	case firewall.ProtocolTCP:
-		layerType = layers.LayerTypeTCP
-	case firewall.ProtocolUDP:
-		layerType = layers.LayerTypeUDP
-	default:
-		return fmt.Errorf("unsupported protocol: %s", protocol)
-	}
-
-	return m.removePortRedirection(localAddr, layerType, sourcePort, targetPort)
-}
-
-// translateInboundPortDNAT applies port-specific DNAT translation to inbound packets.
-func (m *Manager) translateInboundPortDNAT(packetData []byte, d *decoder, srcIP, dstIP netip.Addr) bool {
-	if !m.portDNATEnabled.Load() {
-		return false
-	}
-
-	switch d.decoded[1] {
-	case layers.LayerTypeTCP:
-		dstPort := uint16(d.tcp.DstPort)
-		return m.applyPortRule(packetData, d, srcIP, dstIP, dstPort, layers.LayerTypeTCP, m.rewriteTCPPort)
-	case layers.LayerTypeUDP:
-		dstPort := uint16(d.udp.DstPort)
-		return m.applyPortRule(packetData, d, netip.Addr{}, dstIP, dstPort, layers.LayerTypeUDP, m.rewriteUDPPort)
-	default:
-		return false
-	}
-}
-
-type portRewriteFunc func(packetData []byte, d *decoder, newPort uint16, portOffset int) error
-
-func (m *Manager) applyPortRule(packetData []byte, d *decoder, srcIP, dstIP netip.Addr, port uint16, protocol gopacket.LayerType, rewriteFn portRewriteFunc) bool {
-	m.portDNATMutex.RLock()
-	defer m.portDNATMutex.RUnlock()
-
-	for _, rule := range m.portDNATRules {
-		if rule.protocol != protocol || rule.targetIP.Compare(dstIP) != 0 {
-			continue
-		}
-
-		if rule.targetPort == port && rule.targetIP.Compare(srcIP) == 0 {
-			return false
-		}
-
-		if rule.origPort != port {
-			continue
-		}
-
-		if err := rewriteFn(packetData, d, rule.targetPort, destinationPortOffset); err != nil {
-			m.logger.Error1("failed to rewrite port: %v", err)
-			return false
-		}
-		d.dnatOrigPort = rule.origPort
-		return true
-	}
-	return false
-}
-
-// rewriteTCPPort rewrites a TCP port (source or destination) and updates checksum.
-func (m *Manager) rewriteTCPPort(packetData []byte, d *decoder, newPort uint16, portOffset int) error {
-	ipHeaderLen := int(d.ip4.IHL) * 4
-	if ipHeaderLen < 20 || ipHeaderLen > len(packetData) {
-		return errInvalidIPHeaderLength
-	}
-
-	tcpStart := ipHeaderLen
-	if len(packetData) < tcpStart+4 {
-		return fmt.Errorf("packet too short for TCP header")
-	}
-
-	portStart := tcpStart + portOffset
-	oldPort := binary.BigEndian.Uint16(packetData[portStart : portStart+2])
-	binary.BigEndian.PutUint16(packetData[portStart:portStart+2], newPort)
-
-	if len(packetData) >= tcpStart+18 {
-		checksumOffset := tcpStart + 16
-		oldChecksum := binary.BigEndian.Uint16(packetData[checksumOffset : checksumOffset+2])
-
-		var oldPortBytes, newPortBytes [2]byte
-		binary.BigEndian.PutUint16(oldPortBytes[:], oldPort)
-		binary.BigEndian.PutUint16(newPortBytes[:], newPort)
-
-		newChecksum := incrementalUpdate(oldChecksum, oldPortBytes[:], newPortBytes[:])
-		binary.BigEndian.PutUint16(packetData[checksumOffset:checksumOffset+2], newChecksum)
-	}
-
-	return nil
-}
-
-// rewriteUDPPort rewrites a UDP port (source or destination) and updates checksum.
-func (m *Manager) rewriteUDPPort(packetData []byte, d *decoder, newPort uint16, portOffset int) error {
-	ipHeaderLen := int(d.ip4.IHL) * 4
-	if ipHeaderLen < 20 || ipHeaderLen > len(packetData) {
-		return errInvalidIPHeaderLength
-	}
-
-	udpStart := ipHeaderLen
-	if len(packetData) < udpStart+8 {
-		return fmt.Errorf("packet too short for UDP header")
-	}
-
-	portStart := udpStart + portOffset
-	oldPort := binary.BigEndian.Uint16(packetData[portStart : portStart+2])
-	binary.BigEndian.PutUint16(packetData[portStart:portStart+2], newPort)
-
-	checksumOffset := udpStart + 6
-	if len(packetData) >= udpStart+8 {
-		oldChecksum := binary.BigEndian.Uint16(packetData[checksumOffset : checksumOffset+2])
-		if oldChecksum != 0 {
-			var oldPortBytes, newPortBytes [2]byte
-			binary.BigEndian.PutUint16(oldPortBytes[:], oldPort)
-			binary.BigEndian.PutUint16(newPortBytes[:], newPort)
-
-			newChecksum := incrementalUpdate(oldChecksum, oldPortBytes[:], newPortBytes[:])
-			binary.BigEndian.PutUint16(packetData[checksumOffset:checksumOffset+2], newChecksum)
-		}
-	}
-
-	return nil
-}

client/firewall/uspfilter/nat_bench_test.go

@@ -12,7 +12,6 @@ import (
 
 	log "github.com/sirupsen/logrus"
 
-	"github.com/netbirdio/netbird/client/iface"
 	"github.com/netbirdio/netbird/client/iface/device"
 )
 
@@ -66,7 +65,7 @@ func BenchmarkDNATTranslation(b *testing.B) {
 		b.Run(sc.name, func(b *testing.B) {
 			manager, err := Create(&IFaceMock{
 				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false, flowLogger, iface.DefaultMTU)
+			}, false, flowLogger)
 			require.NoError(b, err)
 			defer func() {
 				require.NoError(b, manager.Close(nil))
@@ -126,7 +125,7 @@ func BenchmarkDNATTranslation(b *testing.B) {
 func BenchmarkDNATConcurrency(b *testing.B) {
 	manager, err := Create(&IFaceMock{
 		SetFilterFunc: func(device.PacketFilter) error { return nil },
-	}, false, flowLogger, iface.DefaultMTU)
+	}, false, flowLogger)
 	require.NoError(b, err)
 	defer func() {
 		require.NoError(b, manager.Close(nil))
@@ -198,7 +197,7 @@ func BenchmarkDNATScaling(b *testing.B) {
 		b.Run(fmt.Sprintf("mappings_%d", count), func(b *testing.B) {
 			manager, err := Create(&IFaceMock{
 				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false, flowLogger, iface.DefaultMTU)
+			}, false, flowLogger)
 			require.NoError(b, err)
 			defer func() {
 				require.NoError(b, manager.Close(nil))
@@ -310,7 +309,7 @@ func BenchmarkChecksumUpdate(b *testing.B) {
 func BenchmarkDNATMemoryAllocations(b *testing.B) {
 	manager, err := Create(&IFaceMock{
 		SetFilterFunc: func(device.PacketFilter) error { return nil },
-	}, false, flowLogger, iface.DefaultMTU)
+	}, false, flowLogger)
 	require.NoError(b, err)
 	defer func() {
 		require.NoError(b, manager.Close(nil))
@@ -415,127 +414,3 @@ func BenchmarkChecksumOptimizations(b *testing.B) {
 		}
 	})
 }
-
-// BenchmarkPortDNAT measures the performance of port DNAT operations
-func BenchmarkPortDNAT(b *testing.B) {
-	scenarios := []struct {
-		name         string
-		proto        layers.IPProtocol
-		setupDNAT    bool
-		useMatchPort bool
-		description  string
-	}{
-		{
-			name:         "tcp_inbound_dnat_match",
-			proto:        layers.IPProtocolTCP,
-			setupDNAT:    true,
-			useMatchPort: true,
-			description:  "TCP inbound port DNAT translation (22 → 22022)",
-		},
-		{
-			name:         "tcp_inbound_dnat_nomatch",
-			proto:        layers.IPProtocolTCP,
-			setupDNAT:    true,
-			useMatchPort: false,
-			description:  "TCP inbound with DNAT configured but no port match",
-		},
-		{
-			name:         "tcp_inbound_no_dnat",
-			proto:        layers.IPProtocolTCP,
-			setupDNAT:    false,
-			useMatchPort: false,
-			description:  "TCP inbound without DNAT (baseline)",
-		},
-		{
-			name:         "udp_inbound_dnat_match",
-			proto:        layers.IPProtocolUDP,
-			setupDNAT:    true,
-			useMatchPort: true,
-			description:  "UDP inbound port DNAT translation (5353 → 22054)",
-		},
-		{
-			name:         "udp_inbound_dnat_nomatch",
-			proto:        layers.IPProtocolUDP,
-			setupDNAT:    true,
-			useMatchPort: false,
-			description:  "UDP inbound with DNAT configured but no port match",
-		},
-		{
-			name:         "udp_inbound_no_dnat",
-			proto:        layers.IPProtocolUDP,
-			setupDNAT:    false,
-			useMatchPort: false,
-			description:  "UDP inbound without DNAT (baseline)",
-		},
-	}
-
-	for _, sc := range scenarios {
-		b.Run(sc.name, func(b *testing.B) {
-			manager, err := Create(&IFaceMock{
-				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false, flowLogger, iface.DefaultMTU)
-			require.NoError(b, err)
-			defer func() {
-				require.NoError(b, manager.Close(nil))
-			}()
-
-			// Set logger to error level to reduce noise during benchmarking
-			manager.SetLogLevel(log.ErrorLevel)
-			defer func() {
-				// Restore to info level after benchmark
-				manager.SetLogLevel(log.InfoLevel)
-			}()
-
-			localAddr := netip.MustParseAddr("100.0.2.175")
-			clientIP := netip.MustParseAddr("100.0.169.249")
-
-			var origPort, targetPort, testPort uint16
-			if sc.proto == layers.IPProtocolTCP {
-				origPort, targetPort = 22, 22022
-			} else {
-				origPort, targetPort = 5353, 22054
-			}
-
-			if sc.useMatchPort {
-				testPort = origPort
-			} else {
-				testPort = 443 // Different port
-			}
-
-			// Setup port DNAT mapping if needed
-			if sc.setupDNAT {
-				err := manager.AddInboundDNAT(localAddr, protocolToFirewall(sc.proto), origPort, targetPort)
-				require.NoError(b, err)
-			}
-
-			// Pre-establish inbound connection for outbound reverse test
-			if sc.setupDNAT && sc.useMatchPort {
-				inboundPacket := generateDNATTestPacket(b, clientIP, localAddr, sc.proto, 54321, origPort)
-				manager.filterInbound(inboundPacket, 0)
-			}
-
-			b.ResetTimer()
-			b.ReportAllocs()
-
-			// Benchmark inbound DNAT translation
-			b.Run("inbound", func(b *testing.B) {
-				for i := 0; i < b.N; i++ {
-					// Create fresh packet each time
-					packet := generateDNATTestPacket(b, clientIP, localAddr, sc.proto, 54321, testPort)
-					manager.filterInbound(packet, 0)
-				}
-			})
-
-			// Benchmark outbound reverse DNAT translation (only if DNAT is set up and port matches)
-			if sc.setupDNAT && sc.useMatchPort {
-				b.Run("outbound_reverse", func(b *testing.B) {
-					for i := 0; i < b.N; i++ {
-						// Create fresh return packet (from target port)
-						packet := generateDNATTestPacket(b, localAddr, clientIP, sc.proto, targetPort, 54321)
-						manager.filterOutbound(packet, 0)
-					}
-				})
-			}
-		})
-	}
-}

client/firewall/uspfilter/nat_test.go

@@ -8,8 +8,6 @@ import (
 	"github.com/google/gopacket/layers"
 	"github.com/stretchr/testify/require"
 
-	firewall "github.com/netbirdio/netbird/client/firewall/manager"
-	"github.com/netbirdio/netbird/client/iface"
 	"github.com/netbirdio/netbird/client/iface/device"
 )
 
@@ -17,7 +15,7 @@ import (
 func TestDNATTranslationCorrectness(t *testing.T) {
 	manager, err := Create(&IFaceMock{
 		SetFilterFunc: func(device.PacketFilter) error { return nil },
-	}, false, flowLogger, iface.DefaultMTU)
+	}, false, flowLogger)
 	require.NoError(t, err)
 	defer func() {
 		require.NoError(t, manager.Close(nil))
@@ -101,7 +99,7 @@ func parsePacket(t testing.TB, packetData []byte) *decoder {
 func TestDNATMappingManagement(t *testing.T) {
 	manager, err := Create(&IFaceMock{
 		SetFilterFunc: func(device.PacketFilter) error { return nil },
-	}, false, flowLogger, iface.DefaultMTU)
+	}, false, flowLogger)
 	require.NoError(t, err)
 	defer func() {
 		require.NoError(t, manager.Close(nil))
@@ -145,111 +143,3 @@ func TestDNATMappingManagement(t *testing.T) {
 	err = manager.RemoveInternalDNATMapping(originalIP)
 	require.Error(t, err, "Should error when removing non-existent mapping")
 }
-
-func TestInboundPortDNAT(t *testing.T) {
-	manager, err := Create(&IFaceMock{
-		SetFilterFunc: func(device.PacketFilter) error { return nil },
-	}, false, flowLogger, iface.DefaultMTU)
-	require.NoError(t, err)
-	defer func() {
-		require.NoError(t, manager.Close(nil))
-	}()
-
-	localAddr := netip.MustParseAddr("100.0.2.175")
-	clientIP := netip.MustParseAddr("100.0.169.249")
-
-	testCases := []struct {
-		name       string
-		protocol   layers.IPProtocol
-		sourcePort uint16
-		targetPort uint16
-	}{
-		{"TCP SSH", layers.IPProtocolTCP, 22, 22022},
-		{"UDP DNS", layers.IPProtocolUDP, 5353, 22054},
-	}
-
-	for _, tc := range testCases {
-		t.Run(tc.name, func(t *testing.T) {
-			err := manager.AddInboundDNAT(localAddr, protocolToFirewall(tc.protocol), tc.sourcePort, tc.targetPort)
-			require.NoError(t, err)
-
-			inboundPacket := generateDNATTestPacket(t, clientIP, localAddr, tc.protocol, 54321, tc.sourcePort)
-			d := parsePacket(t, inboundPacket)
-
-			translated := manager.translateInboundPortDNAT(inboundPacket, d, clientIP, localAddr)
-			require.True(t, translated, "Inbound packet should be translated")
-
-			d = parsePacket(t, inboundPacket)
-			var dstPort uint16
-			switch tc.protocol {
-			case layers.IPProtocolTCP:
-				dstPort = uint16(d.tcp.DstPort)
-			case layers.IPProtocolUDP:
-				dstPort = uint16(d.udp.DstPort)
-			}
-
-			require.Equal(t, tc.targetPort, dstPort, "Destination port should be rewritten to target port")
-
-			err = manager.RemoveInboundDNAT(localAddr, protocolToFirewall(tc.protocol), tc.sourcePort, tc.targetPort)
-			require.NoError(t, err)
-		})
-	}
-}
-
-func TestInboundPortDNATNegative(t *testing.T) {
-	manager, err := Create(&IFaceMock{
-		SetFilterFunc: func(device.PacketFilter) error { return nil },
-	}, false, flowLogger, iface.DefaultMTU)
-	require.NoError(t, err)
-	defer func() {
-		require.NoError(t, manager.Close(nil))
-	}()
-
-	localAddr := netip.MustParseAddr("100.0.2.175")
-	clientIP := netip.MustParseAddr("100.0.169.249")
-
-	err = manager.AddInboundDNAT(localAddr, firewall.ProtocolTCP, 22, 22022)
-	require.NoError(t, err)
-
-	testCases := []struct {
-		name     string
-		protocol layers.IPProtocol
-		srcIP    netip.Addr
-		dstIP    netip.Addr
-		srcPort  uint16
-		dstPort  uint16
-	}{
-		{"Wrong port", layers.IPProtocolTCP, clientIP, localAddr, 54321, 80},
-		{"Wrong IP", layers.IPProtocolTCP, clientIP, netip.MustParseAddr("100.64.0.99"), 54321, 22},
-		{"Wrong protocol", layers.IPProtocolUDP, clientIP, localAddr, 54321, 22},
-		{"ICMP", layers.IPProtocolICMPv4, clientIP, localAddr, 0, 0},
-	}
-
-	for _, tc := range testCases {
-		t.Run(tc.name, func(t *testing.T) {
-			packet := generateDNATTestPacket(t, tc.srcIP, tc.dstIP, tc.protocol, tc.srcPort, tc.dstPort)
-			d := parsePacket(t, packet)
-
-			translated := manager.translateInboundPortDNAT(packet, d, tc.srcIP, tc.dstIP)
-			require.False(t, translated, "Packet should NOT be translated for %s", tc.name)
-
-			d = parsePacket(t, packet)
-			if tc.protocol == layers.IPProtocolTCP {
-				require.Equal(t, tc.dstPort, uint16(d.tcp.DstPort), "Port should remain unchanged")
-			} else if tc.protocol == layers.IPProtocolUDP {
-				require.Equal(t, tc.dstPort, uint16(d.udp.DstPort), "Port should remain unchanged")
-			}
-		})
-	}
-}
-
-func protocolToFirewall(proto layers.IPProtocol) firewall.Protocol {
-	switch proto {
-	case layers.IPProtocolTCP:
-		return firewall.ProtocolTCP
-	case layers.IPProtocolUDP:
-		return firewall.ProtocolUDP
-	default:
-		return firewall.ProtocolALL
-	}
-}

client/firewall/uspfilter/tracer.go

@@ -16,33 +16,25 @@ type PacketStage int
 
 const (
 	StageReceived PacketStage = iota
-	StageInboundPortDNAT
-	StageInbound1to1NAT
 	StageConntrack
 	StagePeerACL
 	StageRouting
 	StageRouteACL
 	StageForwarding
 	StageCompleted
-	StageOutbound1to1NAT
-	StageOutboundPortReverse
 )
 
 const msgProcessingCompleted = "Processing completed"
 
 func (s PacketStage) String() string {
 	return map[PacketStage]string{
-		StageReceived:            "Received",
-		StageInboundPortDNAT:     "Inbound Port DNAT",
-		StageInbound1to1NAT:      "Inbound 1:1 NAT",
-		StageConntrack:           "Connection Tracking",
-		StagePeerACL:             "Peer ACL",
-		StageRouting:             "Routing",
-		StageRouteACL:            "Route ACL",
-		StageForwarding:          "Forwarding",
-		StageCompleted:           "Completed",
-		StageOutbound1to1NAT:     "Outbound 1:1 NAT",
-		StageOutboundPortReverse: "Outbound DNAT Reverse",
+		StageReceived:   "Received",
+		StageConntrack:  "Connection Tracking",
+		StagePeerACL:    "Peer ACL",
+		StageRouting:    "Routing",
+		StageRouteACL:   "Route ACL",
+		StageForwarding: "Forwarding",
+		StageCompleted:  "Completed",
 	}[s]
 }
 
@@ -269,10 +261,6 @@ func (m *Manager) TracePacket(packetData []byte, direction fw.RuleDirection) *Pa
 }
 
 func (m *Manager) traceInbound(packetData []byte, trace *PacketTrace, d *decoder, srcIP netip.Addr, dstIP netip.Addr) *PacketTrace {
-	if m.handleInboundDNAT(trace, packetData, d, &srcIP, &dstIP) {
-		return trace
-	}
-
 	if m.stateful && m.handleConntrackState(trace, d, srcIP, dstIP) {
 		return trace
 	}
@@ -326,7 +314,7 @@ func (m *Manager) buildConntrackStateMessage(d *decoder) string {
 func (m *Manager) handleLocalDelivery(trace *PacketTrace, packetData []byte, d *decoder, srcIP, dstIP netip.Addr) bool {
 	trace.AddResult(StageRouting, "Packet destined for local delivery", true)
 
-	ruleId, blocked := m.peerACLsBlock(srcIP, d, packetData)
+	ruleId, blocked := m.peerACLsBlock(srcIP, packetData, m.incomingRules, d)
 
 	strRuleId := "<no id>"
 	if ruleId != nil {
@@ -412,16 +400,7 @@ func (m *Manager) addForwardingResult(trace *PacketTrace, action, remoteAddr str
 }
 
 func (m *Manager) traceOutbound(packetData []byte, trace *PacketTrace) *PacketTrace {
-	d := m.decoders.Get().(*decoder)
-	defer m.decoders.Put(d)
-
-	if err := d.parser.DecodeLayers(packetData, &d.decoded); err != nil {
-		trace.AddResult(StageCompleted, "Packet dropped - decode error", false)
-		return trace
-	}
-
-	m.handleOutboundDNAT(trace, packetData, d)
-
+	// will create or update the connection state
 	dropped := m.filterOutbound(packetData, 0)
 	if dropped {
 		trace.AddResult(StageCompleted, "Packet dropped by outgoing hook", false)
@@ -430,199 +409,3 @@ func (m *Manager) traceOutbound(packetData []byte, trace *PacketTrace) *PacketTr
 	}
 	return trace
 }
-
-func (m *Manager) handleInboundDNAT(trace *PacketTrace, packetData []byte, d *decoder, srcIP, dstIP *netip.Addr) bool {
-	portDNATApplied := m.traceInboundPortDNAT(trace, packetData, d)
-	if portDNATApplied {
-		if err := d.parser.DecodeLayers(packetData, &d.decoded); err != nil {
-			trace.AddResult(StageInboundPortDNAT, "Failed to re-decode after port DNAT", false)
-			return true
-		}
-		*srcIP, *dstIP = m.extractIPs(d)
-		trace.DestinationPort = m.getDestPort(d)
-	}
-
-	nat1to1Applied := m.traceInbound1to1NAT(trace, packetData, d)
-	if nat1to1Applied {
-		if err := d.parser.DecodeLayers(packetData, &d.decoded); err != nil {
-			trace.AddResult(StageInbound1to1NAT, "Failed to re-decode after 1:1 NAT", false)
-			return true
-		}
-		*srcIP, *dstIP = m.extractIPs(d)
-	}
-
-	return false
-}
-
-func (m *Manager) traceInboundPortDNAT(trace *PacketTrace, packetData []byte, d *decoder) bool {
-	if !m.portDNATEnabled.Load() {
-		trace.AddResult(StageInboundPortDNAT, "Port DNAT not enabled", true)
-		return false
-	}
-
-	if len(packetData) < 20 || d.decoded[0] != layers.LayerTypeIPv4 {
-		trace.AddResult(StageInboundPortDNAT, "Not IPv4, skipping port DNAT", true)
-		return false
-	}
-
-	if len(d.decoded) < 2 {
-		trace.AddResult(StageInboundPortDNAT, "No transport layer, skipping port DNAT", true)
-		return false
-	}
-
-	protocol := d.decoded[1]
-	if protocol != layers.LayerTypeTCP && protocol != layers.LayerTypeUDP {
-		trace.AddResult(StageInboundPortDNAT, "Not TCP/UDP, skipping port DNAT", true)
-		return false
-	}
-
-	srcIP := netip.AddrFrom4([4]byte{packetData[12], packetData[13], packetData[14], packetData[15]})
-	dstIP := netip.AddrFrom4([4]byte{packetData[16], packetData[17], packetData[18], packetData[19]})
-	var originalPort uint16
-	if protocol == layers.LayerTypeTCP {
-		originalPort = uint16(d.tcp.DstPort)
-	} else {
-		originalPort = uint16(d.udp.DstPort)
-	}
-
-	translated := m.translateInboundPortDNAT(packetData, d, srcIP, dstIP)
-	if translated {
-		ipHeaderLen := int((packetData[0] & 0x0F) * 4)
-		translatedPort := uint16(packetData[ipHeaderLen+2])<<8 | uint16(packetData[ipHeaderLen+3])
-
-		protoStr := "TCP"
-		if protocol == layers.LayerTypeUDP {
-			protoStr = "UDP"
-		}
-		msg := fmt.Sprintf("%s port DNAT applied: %s:%d -> %s:%d", protoStr, dstIP, originalPort, dstIP, translatedPort)
-		trace.AddResult(StageInboundPortDNAT, msg, true)
-		return true
-	}
-
-	trace.AddResult(StageInboundPortDNAT, "No matching port DNAT rule", true)
-	return false
-}
-
-func (m *Manager) traceInbound1to1NAT(trace *PacketTrace, packetData []byte, d *decoder) bool {
-	if !m.dnatEnabled.Load() {
-		trace.AddResult(StageInbound1to1NAT, "1:1 NAT not enabled", true)
-		return false
-	}
-
-	srcIP := netip.AddrFrom4([4]byte{packetData[12], packetData[13], packetData[14], packetData[15]})
-
-	translated := m.translateInboundReverse(packetData, d)
-	if translated {
-		m.dnatMutex.RLock()
-		translatedIP, exists := m.dnatBiMap.getOriginal(srcIP)
-		m.dnatMutex.RUnlock()
-
-		if exists {
-			msg := fmt.Sprintf("1:1 NAT reverse applied: %s -> %s", srcIP, translatedIP)
-			trace.AddResult(StageInbound1to1NAT, msg, true)
-			return true
-		}
-	}
-
-	trace.AddResult(StageInbound1to1NAT, "No matching 1:1 NAT rule", true)
-	return false
-}
-
-func (m *Manager) handleOutboundDNAT(trace *PacketTrace, packetData []byte, d *decoder) {
-	m.traceOutbound1to1NAT(trace, packetData, d)
-	m.traceOutboundPortReverse(trace, packetData, d)
-}
-
-func (m *Manager) traceOutbound1to1NAT(trace *PacketTrace, packetData []byte, d *decoder) bool {
-	if !m.dnatEnabled.Load() {
-		trace.AddResult(StageOutbound1to1NAT, "1:1 NAT not enabled", true)
-		return false
-	}
-
-	dstIP := netip.AddrFrom4([4]byte{packetData[16], packetData[17], packetData[18], packetData[19]})
-
-	translated := m.translateOutboundDNAT(packetData, d)
-	if translated {
-		m.dnatMutex.RLock()
-		translatedIP, exists := m.dnatMappings[dstIP]
-		m.dnatMutex.RUnlock()
-
-		if exists {
-			msg := fmt.Sprintf("1:1 NAT applied: %s -> %s", dstIP, translatedIP)
-			trace.AddResult(StageOutbound1to1NAT, msg, true)
-			return true
-		}
-	}
-
-	trace.AddResult(StageOutbound1to1NAT, "No matching 1:1 NAT rule", true)
-	return false
-}
-
-func (m *Manager) traceOutboundPortReverse(trace *PacketTrace, packetData []byte, d *decoder) bool {
-	if !m.portDNATEnabled.Load() {
-		trace.AddResult(StageOutboundPortReverse, "Port DNAT not enabled", true)
-		return false
-	}
-
-	if len(packetData) < 20 || d.decoded[0] != layers.LayerTypeIPv4 {
-		trace.AddResult(StageOutboundPortReverse, "Not IPv4, skipping port reverse", true)
-		return false
-	}
-
-	if len(d.decoded) < 2 {
-		trace.AddResult(StageOutboundPortReverse, "No transport layer, skipping port reverse", true)
-		return false
-	}
-
-	srcIP := netip.AddrFrom4([4]byte{packetData[12], packetData[13], packetData[14], packetData[15]})
-	dstIP := netip.AddrFrom4([4]byte{packetData[16], packetData[17], packetData[18], packetData[19]})
-
-	var origPort uint16
-	transport := d.decoded[1]
-	switch transport {
-	case layers.LayerTypeTCP:
-		srcPort := uint16(d.tcp.SrcPort)
-		dstPort := uint16(d.tcp.DstPort)
-		conn, exists := m.tcpTracker.GetConnection(dstIP, dstPort, srcIP, srcPort)
-		if exists {
-			origPort = uint16(conn.DNATOrigPort.Load())
-		}
-		if origPort != 0 {
-			msg := fmt.Sprintf("TCP DNAT reverse (tracked connection): %s:%d -> %s:%d", srcIP, srcPort, srcIP, origPort)
-			trace.AddResult(StageOutboundPortReverse, msg, true)
-			return true
-		}
-	case layers.LayerTypeUDP:
-		srcPort := uint16(d.udp.SrcPort)
-		dstPort := uint16(d.udp.DstPort)
-		conn, exists := m.udpTracker.GetConnection(dstIP, dstPort, srcIP, srcPort)
-		if exists {
-			origPort = uint16(conn.DNATOrigPort.Load())
-		}
-		if origPort != 0 {
-			msg := fmt.Sprintf("UDP DNAT reverse (tracked connection): %s:%d -> %s:%d", srcIP, srcPort, srcIP, origPort)
-			trace.AddResult(StageOutboundPortReverse, msg, true)
-			return true
-		}
-	default:
-		trace.AddResult(StageOutboundPortReverse, "Not TCP/UDP, skipping port reverse", true)
-		return false
-	}
-
-	trace.AddResult(StageOutboundPortReverse, "No tracked connection for DNAT reverse", true)
-	return false
-}
-
-func (m *Manager) getDestPort(d *decoder) uint16 {
-	if len(d.decoded) < 2 {
-		return 0
-	}
-	switch d.decoded[1] {
-	case layers.LayerTypeTCP:
-		return uint16(d.tcp.DstPort)
-	case layers.LayerTypeUDP:
-		return uint16(d.udp.DstPort)
-	default:
-		return 0
-	}
-}

client/firewall/uspfilter/tracer_test.go

@@ -10,7 +10,6 @@ import (
 	fw "github.com/netbirdio/netbird/client/firewall/manager"
 	"github.com/netbirdio/netbird/client/firewall/uspfilter/conntrack"
 	"github.com/netbirdio/netbird/client/firewall/uspfilter/forwarder"
-	"github.com/netbirdio/netbird/client/iface"
 	"github.com/netbirdio/netbird/client/iface/device"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
 )
@@ -45,7 +44,7 @@ func TestTracePacket(t *testing.T) {
 			},
 		}
 
-		m, err := Create(ifaceMock, false, flowLogger, iface.DefaultMTU)
+		m, err := Create(ifaceMock, false, flowLogger)
 		require.NoError(t, err)
 
 		if !statefulMode {
@@ -105,8 +104,6 @@ func TestTracePacket(t *testing.T) {
 			},
 			expectedStages: []PacketStage{
 				StageReceived,
-				StageInboundPortDNAT,
-				StageInbound1to1NAT,
 				StageConntrack,
 				StageRouting,
 				StagePeerACL,
@@ -129,8 +126,6 @@ func TestTracePacket(t *testing.T) {
 			},
 			expectedStages: []PacketStage{
 				StageReceived,
-				StageInboundPortDNAT,
-				StageInbound1to1NAT,
 				StageConntrack,
 				StageRouting,
 				StagePeerACL,
@@ -158,8 +153,6 @@ func TestTracePacket(t *testing.T) {
 			},
 			expectedStages: []PacketStage{
 				StageReceived,
-				StageInboundPortDNAT,
-				StageInbound1to1NAT,
 				StageConntrack,
 				StageRouting,
 				StagePeerACL,
@@ -186,8 +179,6 @@ func TestTracePacket(t *testing.T) {
 			},
 			expectedStages: []PacketStage{
 				StageReceived,
-				StageInboundPortDNAT,
-				StageInbound1to1NAT,
 				StageConntrack,
 				StageRouting,
 				StagePeerACL,
@@ -213,8 +204,6 @@ func TestTracePacket(t *testing.T) {
 			},
 			expectedStages: []PacketStage{
 				StageReceived,
-				StageInboundPortDNAT,
-				StageInbound1to1NAT,
 				StageConntrack,
 				StageRouting,
 				StageRouteACL,
@@ -239,8 +228,6 @@ func TestTracePacket(t *testing.T) {
 			},
 			expectedStages: []PacketStage{
 				StageReceived,
-				StageInboundPortDNAT,
-				StageInbound1to1NAT,
 				StageConntrack,
 				StageRouting,
 				StageRouteACL,
@@ -259,8 +246,6 @@ func TestTracePacket(t *testing.T) {
 			},
 			expectedStages: []PacketStage{
 				StageReceived,
-				StageInboundPortDNAT,
-				StageInbound1to1NAT,
 				StageConntrack,
 				StageRouting,
 				StageRouteACL,
@@ -279,8 +264,6 @@ func TestTracePacket(t *testing.T) {
 			},
 			expectedStages: []PacketStage{
 				StageReceived,
-				StageInboundPortDNAT,
-				StageInbound1to1NAT,
 				StageConntrack,
 				StageRouting,
 				StageCompleted,
@@ -304,8 +287,6 @@ func TestTracePacket(t *testing.T) {
 			},
 			expectedStages: []PacketStage{
 				StageReceived,
-				StageInboundPortDNAT,
-				StageInbound1to1NAT,
 				StageConntrack,
 				StageCompleted,
 			},
@@ -320,8 +301,6 @@ func TestTracePacket(t *testing.T) {
 			},
 			expectedStages: []PacketStage{
 				StageReceived,
-				StageOutbound1to1NAT,
-				StageOutboundPortReverse,
 				StageCompleted,
 			},
 			expectedAllow: true,
@@ -340,8 +319,6 @@ func TestTracePacket(t *testing.T) {
 			},
 			expectedStages: []PacketStage{
 				StageReceived,
-				StageInboundPortDNAT,
-				StageInbound1to1NAT,
 				StageConntrack,
 				StageRouting,
 				StagePeerACL,
@@ -363,8 +340,6 @@ func TestTracePacket(t *testing.T) {
 			},
 			expectedStages: []PacketStage{
 				StageReceived,
-				StageInboundPortDNAT,
-				StageInbound1to1NAT,
 				StageConntrack,
 				StageRouting,
 				StagePeerACL,
@@ -387,8 +362,6 @@ func TestTracePacket(t *testing.T) {
 			},
 			expectedStages: []PacketStage{
 				StageReceived,
-				StageInboundPortDNAT,
-				StageInbound1to1NAT,
 				StageConntrack,
 				StageRouting,
 				StagePeerACL,
@@ -409,8 +382,6 @@ func TestTracePacket(t *testing.T) {
 			},
 			expectedStages: []PacketStage{
 				StageReceived,
-				StageInboundPortDNAT,
-				StageInbound1to1NAT,
 				StageConntrack,
 				StageRouting,
 				StagePeerACL,
@@ -435,8 +406,6 @@ func TestTracePacket(t *testing.T) {
 			},
 			expectedStages: []PacketStage{
 				StageReceived,
-				StageInboundPortDNAT,
-				StageInbound1to1NAT,
 				StageRouting,
 				StagePeerACL,
 				StageCompleted,

client/grpc/dialer.go

@@ -1,93 +0,0 @@
-package grpc
-
-import (
-	"context"
-	"crypto/tls"
-	"crypto/x509"
-	"errors"
-	"fmt"
-	"runtime"
-	"time"
-
-	"github.com/cenkalti/backoff/v4"
-	log "github.com/sirupsen/logrus"
-	"google.golang.org/grpc"
-	"google.golang.org/grpc/connectivity"
-	"google.golang.org/grpc/credentials"
-	"google.golang.org/grpc/credentials/insecure"
-	"google.golang.org/grpc/keepalive"
-
-	"github.com/netbirdio/netbird/util/embeddedroots"
-)
-
-// ErrConnectionShutdown indicates that the connection entered shutdown state before becoming ready
-var ErrConnectionShutdown = errors.New("connection shutdown before ready")
-
-// Backoff returns a backoff configuration for gRPC calls
-func Backoff(ctx context.Context) backoff.BackOff {
-	b := backoff.NewExponentialBackOff()
-	b.MaxElapsedTime = 10 * time.Second
-	b.Clock = backoff.SystemClock
-	return backoff.WithContext(b, ctx)
-}
-
-// waitForConnectionReady blocks until the connection becomes ready or fails.
-// Returns an error if the connection times out, is cancelled, or enters shutdown state.
-func waitForConnectionReady(ctx context.Context, conn *grpc.ClientConn) error {
-	conn.Connect()
-
-	state := conn.GetState()
-	for state != connectivity.Ready && state != connectivity.Shutdown {
-		if !conn.WaitForStateChange(ctx, state) {
-			return fmt.Errorf("wait state change from %s: %w", state, ctx.Err())
-		}
-		state = conn.GetState()
-	}
-
-	if state == connectivity.Shutdown {
-		return ErrConnectionShutdown
-	}
-
-	return nil
-}
-
-// CreateConnection creates a gRPC client connection with the appropriate transport options.
-// The component parameter specifies the WebSocket proxy component path (e.g., "/management", "/signal").
-func CreateConnection(ctx context.Context, addr string, tlsEnabled bool, component string) (*grpc.ClientConn, error) {
-	transportOption := grpc.WithTransportCredentials(insecure.NewCredentials())
-	// for js, the outer websocket layer takes care of tls
-	if tlsEnabled && runtime.GOOS != "js" {
-		certPool, err := x509.SystemCertPool()
-		if err != nil || certPool == nil {
-			log.Debugf("System cert pool not available; falling back to embedded cert, error: %v", err)
-			certPool = embeddedroots.Get()
-		}
-
-		transportOption = grpc.WithTransportCredentials(credentials.NewTLS(&tls.Config{
-			RootCAs: certPool,
-		}))
-	}
-
-	conn, err := grpc.NewClient(
-		addr,
-		transportOption,
-		WithCustomDialer(tlsEnabled, component),
-		grpc.WithKeepaliveParams(keepalive.ClientParameters{
-			Time:    30 * time.Second,
-			Timeout: 10 * time.Second,
-		}),
-	)
-	if err != nil {
-		return nil, fmt.Errorf("new client: %w", err)
-	}
-
-	ctx, cancel := context.WithTimeout(ctx, 30*time.Second)
-	defer cancel()
-
-	if err := waitForConnectionReady(ctx, conn); err != nil {
-		_ = conn.Close()
-		return nil, err
-	}
-
-	return conn, nil
-}

client/grpc/dialer_generic.go

@@ -1,43 +0,0 @@
-//go:build !js
-
-package grpc
-
-import (
-	"context"
-	"fmt"
-	"net"
-	"os/user"
-	"runtime"
-
-	"google.golang.org/grpc/codes"
-	"google.golang.org/grpc/status"
-
-	log "github.com/sirupsen/logrus"
-	"google.golang.org/grpc"
-
-	nbnet "github.com/netbirdio/netbird/client/net"
-)
-
-func WithCustomDialer(_ bool, _ string) grpc.DialOption {
-	return grpc.WithContextDialer(func(ctx context.Context, addr string) (net.Conn, error) {
-		if runtime.GOOS == "linux" {
-			currentUser, err := user.Current()
-			if err != nil {
-				return nil, status.Errorf(codes.FailedPrecondition, "failed to get current user: %v", err)
-			}
-
-			// the custom dialer requires root permissions which are not required for use cases run as non-root
-			if currentUser.Uid != "0" {
-				log.Debug("Not running as root, using standard dialer")
-				dialer := &net.Dialer{}
-				return dialer.DialContext(ctx, "tcp", addr)
-			}
-		}
-
-		conn, err := nbnet.NewDialer().DialContext(ctx, "tcp", addr)
-		if err != nil {
-			return nil, fmt.Errorf("nbnet.NewDialer().DialContext: %w", err)
-		}
-		return conn, nil
-	})
-}

client/grpc/dialer_js.go

@@ -1,13 +0,0 @@
-package grpc
-
-import (
-	"google.golang.org/grpc"
-
-	"github.com/netbirdio/netbird/util/wsproxy/client"
-)
-
-// WithCustomDialer returns a gRPC dial option that uses WebSocket transport for WASM/JS environments.
-// The component parameter specifies the WebSocket proxy component path (e.g., "/management", "/signal").
-func WithCustomDialer(tlsEnabled bool, component string) grpc.DialOption {
-	return client.WithWebSocketDialer(tlsEnabled, component)
-}

client/iface/bind/control.go

@@ -3,7 +3,7 @@ package bind
 import (
 	wireguard "golang.zx2c4.com/wireguard/conn"
 
-	nbnet "github.com/netbirdio/netbird/client/net"
+	nbnet "github.com/netbirdio/netbird/util/net"
 )
 
 // TODO: This is most likely obsolete since the control fns should be called by the wrapped udpconn (ice_bind.go)

client/iface/bind/endpoint.go

@@ -1,17 +1,5 @@
 package bind
 
-import (
-	"net"
-
-	wgConn "golang.zx2c4.com/wireguard/conn"
-)
+import wgConn "golang.zx2c4.com/wireguard/conn"
 
 type Endpoint = wgConn.StdNetEndpoint
-
-func EndpointToUDPAddr(e Endpoint) *net.UDPAddr {
-	return &net.UDPAddr{
-		IP:   e.Addr().AsSlice(),
-		Port: int(e.Port()),
-		Zone: e.Addr().Zone(),
-	}
-}

client/iface/bind/error.go

@@ -1,7 +0,0 @@
-package bind
-
-import "fmt"
-
-var (
-	ErrUDPMUXNotSupported = fmt.Errorf("UDPMUX is not supported in WASM")
-)

client/iface/bind/ice_bind.go

@@ -1,9 +1,6 @@
-//go:build !js
-
 package bind
 
 import (
-	"context"
 	"encoding/binary"
 	"fmt"
 	"net"
@@ -11,18 +8,22 @@ import (
 	"runtime"
 	"sync"
 
-	"github.com/pion/stun/v3"
+	"github.com/pion/stun/v2"
 	"github.com/pion/transport/v3"
 	log "github.com/sirupsen/logrus"
 	"golang.org/x/net/ipv4"
 	"golang.org/x/net/ipv6"
 	wgConn "golang.zx2c4.com/wireguard/conn"
 
-	"github.com/netbirdio/netbird/client/iface/udpmux"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
-	nbnet "github.com/netbirdio/netbird/client/net"
+	nbnet "github.com/netbirdio/netbird/util/net"
 )
 
+type RecvMessage struct {
+	Endpoint *Endpoint
+	Buffer   []byte
+}
+
 type receiverCreator struct {
 	iceBind *ICEBind
 }
@@ -40,38 +41,35 @@ func (rc receiverCreator) CreateIPv4ReceiverFn(pc *ipv4.PacketConn, conn *net.UD
 // use the port because in the Send function the wgConn.Endpoint the port info is not exported.
 type ICEBind struct {
 	*wgConn.StdNetBind
+	RecvChan chan RecvMessage
 
 	transportNet transport.Net
-	filterFn     udpmux.FilterFn
-	address      wgaddr.Address
-	mtu          uint16
-
-	endpoints   map[netip.Addr]net.Conn
-	endpointsMu sync.Mutex
-	recvChan    chan recvMessage
+	filterFn     FilterFn
+	endpoints    map[netip.Addr]net.Conn
+	endpointsMu  sync.Mutex
 	// every time when Close() is called (i.e. BindUpdate()) we need to close exit from the receiveRelayed and create a
 	// new closed channel. With the closedChanMu we can safely close the channel and create a new one
-	closedChan       chan struct{}
-	closedChanMu     sync.RWMutex // protect the closeChan recreation from reading from it.
-	closed           bool
-	activityRecorder *ActivityRecorder
+	closedChan   chan struct{}
+	closedChanMu sync.RWMutex // protect the closeChan recreation from reading from it.
+	closed       bool
 
-	muUDPMux sync.Mutex
-	udpMux   *udpmux.UniversalUDPMuxDefault
+	muUDPMux         sync.Mutex
+	udpMux           *UniversalUDPMuxDefault
+	address          wgaddr.Address
+	activityRecorder *ActivityRecorder
 }
 
-func NewICEBind(transportNet transport.Net, filterFn udpmux.FilterFn, address wgaddr.Address, mtu uint16) *ICEBind {
+func NewICEBind(transportNet transport.Net, filterFn FilterFn, address wgaddr.Address) *ICEBind {
 	b, _ := wgConn.NewStdNetBind().(*wgConn.StdNetBind)
 	ib := &ICEBind{
 		StdNetBind:       b,
+		RecvChan:         make(chan RecvMessage, 1),
 		transportNet:     transportNet,
 		filterFn:         filterFn,
-		address:          address,
-		mtu:              mtu,
 		endpoints:        make(map[netip.Addr]net.Conn),
-		recvChan:         make(chan recvMessage, 1),
 		closedChan:       make(chan struct{}),
 		closed:           true,
+		address:          address,
 		activityRecorder: NewActivityRecorder(),
 	}
 
@@ -111,7 +109,7 @@ func (s *ICEBind) ActivityRecorder() *ActivityRecorder {
 }
 
 // GetICEMux returns the ICE UDPMux that was created and used by ICEBind
-func (s *ICEBind) GetICEMux() (*udpmux.UniversalUDPMuxDefault, error) {
+func (s *ICEBind) GetICEMux() (*UniversalUDPMuxDefault, error) {
 	s.muUDPMux.Lock()
 	defer s.muUDPMux.Unlock()
 	if s.udpMux == nil {
@@ -134,16 +132,6 @@ func (b *ICEBind) RemoveEndpoint(fakeIP netip.Addr) {
 	delete(b.endpoints, fakeIP)
 }
 
-func (b *ICEBind) ReceiveFromEndpoint(ctx context.Context, ep *Endpoint, buf []byte) {
-	select {
-	case <-b.closedChan:
-		return
-	case <-ctx.Done():
-		return
-	case b.recvChan <- recvMessage{ep, buf}:
-	}
-}
-
 func (b *ICEBind) Send(bufs [][]byte, ep wgConn.Endpoint) error {
 	b.endpointsMu.Lock()
 	conn, ok := b.endpoints[ep.DstIP()]
@@ -164,13 +152,12 @@ func (s *ICEBind) createIPv4ReceiverFn(pc *ipv4.PacketConn, conn *net.UDPConn, r
 	s.muUDPMux.Lock()
 	defer s.muUDPMux.Unlock()
 
-	s.udpMux = udpmux.NewUniversalUDPMuxDefault(
-		udpmux.UniversalUDPMuxParams{
+	s.udpMux = NewUniversalUDPMuxDefault(
+		UniversalUDPMuxParams{
 			UDPConn:   nbnet.WrapPacketConn(conn),
 			Net:       s.transportNet,
 			FilterFn:  s.filterFn,
 			WGAddress: s.address,
-			MTU:       s.mtu,
 		},
 	)
 	return func(bufs [][]byte, sizes []int, eps []wgConn.Endpoint) (n int, err error) {
@@ -276,7 +263,7 @@ func (c *ICEBind) receiveRelayed(buffs [][]byte, sizes []int, eps []wgConn.Endpo
 	select {
 	case <-c.closedChan:
 		return 0, net.ErrClosed
-	case msg, ok := <-c.recvChan:
+	case msg, ok := <-c.RecvChan:
 		if !ok {
 			return 0, net.ErrClosed
 		}

client/iface/bind/recv_msg.go

@@ -1,6 +0,0 @@
-package bind
-
-type recvMessage struct {
-	Endpoint *Endpoint
-	Buffer   []byte
-}

client/iface/bind/relay_bind.go

@@ -1,125 +0,0 @@
-package bind
-
-import (
-	"context"
-	"net"
-	"net/netip"
-	"sync"
-
-	log "github.com/sirupsen/logrus"
-	"golang.zx2c4.com/wireguard/conn"
-
-	"github.com/netbirdio/netbird/client/iface/udpmux"
-)
-
-// RelayBindJS is a conn.Bind implementation for WebAssembly environments.
-// Do not limit to build only js, because we want to be able to run tests
-type RelayBindJS struct {
-	*conn.StdNetBind
-
-	recvChan         chan recvMessage
-	endpoints        map[netip.Addr]net.Conn
-	endpointsMu      sync.Mutex
-	activityRecorder *ActivityRecorder
-	ctx              context.Context
-	cancel           context.CancelFunc
-}
-
-func NewRelayBindJS() *RelayBindJS {
-	return &RelayBindJS{
-		recvChan:         make(chan recvMessage, 100),
-		endpoints:        make(map[netip.Addr]net.Conn),
-		activityRecorder: NewActivityRecorder(),
-	}
-}
-
-// Open creates a receive function for handling relay packets in WASM.
-func (s *RelayBindJS) Open(uport uint16) ([]conn.ReceiveFunc, uint16, error) {
-	log.Debugf("Open: creating receive function for port %d", uport)
-
-	s.ctx, s.cancel = context.WithCancel(context.Background())
-
-	receiveFn := func(bufs [][]byte, sizes []int, eps []conn.Endpoint) (int, error) {
-		select {
-		case <-s.ctx.Done():
-			return 0, net.ErrClosed
-		case msg, ok := <-s.recvChan:
-			if !ok {
-				return 0, net.ErrClosed
-			}
-			copy(bufs[0], msg.Buffer)
-			sizes[0] = len(msg.Buffer)
-			eps[0] = conn.Endpoint(msg.Endpoint)
-			return 1, nil
-		}
-	}
-
-	log.Debugf("Open: receive function created, returning port %d", uport)
-	return []conn.ReceiveFunc{receiveFn}, uport, nil
-}
-
-func (s *RelayBindJS) Close() error {
-	if s.cancel == nil {
-		return nil
-	}
-	log.Debugf("close RelayBindJS")
-	s.cancel()
-	return nil
-}
-
-func (s *RelayBindJS) ReceiveFromEndpoint(ctx context.Context, ep *Endpoint, buf []byte) {
-	select {
-	case <-s.ctx.Done():
-		return
-	case <-ctx.Done():
-		return
-	case s.recvChan <- recvMessage{ep, buf}:
-	}
-}
-
-// Send forwards packets through the relay connection for WASM.
-func (s *RelayBindJS) Send(bufs [][]byte, ep conn.Endpoint) error {
-	if ep == nil {
-		return nil
-	}
-
-	fakeIP := ep.DstIP()
-
-	s.endpointsMu.Lock()
-	relayConn, ok := s.endpoints[fakeIP]
-	s.endpointsMu.Unlock()
-
-	if !ok {
-		return nil
-	}
-
-	for _, buf := range bufs {
-		if _, err := relayConn.Write(buf); err != nil {
-			return err
-		}
-	}
-
-	return nil
-}
-
-func (b *RelayBindJS) SetEndpoint(fakeIP netip.Addr, conn net.Conn) {
-	b.endpointsMu.Lock()
-	b.endpoints[fakeIP] = conn
-	b.endpointsMu.Unlock()
-}
-
-func (s *RelayBindJS) RemoveEndpoint(fakeIP netip.Addr) {
-	s.endpointsMu.Lock()
-	defer s.endpointsMu.Unlock()
-
-	delete(s.endpoints, fakeIP)
-}
-
-// GetICEMux returns the ICE UDPMux that was created and used by ICEBind
-func (s *RelayBindJS) GetICEMux() (*udpmux.UniversalUDPMuxDefault, error) {
-	return nil, ErrUDPMUXNotSupported
-}
-
-func (s *RelayBindJS) ActivityRecorder() *ActivityRecorder {
-	return s.activityRecorder
-}

client/iface/bind/udp_mux.go

@@ -1,4 +1,4 @@
-package udpmux
+package bind
 
 import (
 	"fmt"
@@ -8,9 +8,9 @@ import (
 	"strings"
 	"sync"
 
-	"github.com/pion/ice/v4"
+	"github.com/pion/ice/v3"
 	"github.com/pion/logging"
-	"github.com/pion/stun/v3"
+	"github.com/pion/stun/v2"
 	"github.com/pion/transport/v3"
 	"github.com/pion/transport/v3/stdnet"
 	log "github.com/sirupsen/logrus"
@@ -22,9 +22,9 @@ import (
 
 const receiveMTU = 8192
 
-// SingleSocketUDPMux is an implementation of the interface
-type SingleSocketUDPMux struct {
-	params Params
+// UDPMuxDefault is an implementation of the interface
+type UDPMuxDefault struct {
+	params UDPMuxParams
 
 	closedChan chan struct{}
 	closeOnce  sync.Once
@@ -32,9 +32,6 @@ type SingleSocketUDPMux struct {
 	// connsIPv4 and connsIPv6 are maps of all udpMuxedConn indexed by ufrag|network|candidateType
 	connsIPv4, connsIPv6 map[string]*udpMuxedConn
 
-	// candidateConnMap maps local candidate IDs to their corresponding connection.
-	candidateConnMap map[string]*udpMuxedConn
-
 	addressMapMu sync.RWMutex
 	addressMap   map[string][]*udpMuxedConn
 
@@ -49,8 +46,8 @@ type SingleSocketUDPMux struct {
 
 const maxAddrSize = 512
 
-// Params are parameters for UDPMux.
-type Params struct {
+// UDPMuxParams are parameters for UDPMux.
+type UDPMuxParams struct {
 	Logger  logging.LeveledLogger
 	UDPConn net.PacketConn
 
@@ -150,19 +147,18 @@ func isZeros(ip net.IP) bool {
 	return true
 }
 
-// NewSingleSocketUDPMux creates an implementation of UDPMux
-func NewSingleSocketUDPMux(params Params) *SingleSocketUDPMux {
+// NewUDPMuxDefault creates an implementation of UDPMux
+func NewUDPMuxDefault(params UDPMuxParams) *UDPMuxDefault {
 	if params.Logger == nil {
 		params.Logger = getLogger()
 	}
 
-	mux := &SingleSocketUDPMux{
-		addressMap:       map[string][]*udpMuxedConn{},
-		params:           params,
-		connsIPv4:        make(map[string]*udpMuxedConn),
-		connsIPv6:        make(map[string]*udpMuxedConn),
-		candidateConnMap: make(map[string]*udpMuxedConn),
-		closedChan:       make(chan struct{}, 1),
+	mux := &UDPMuxDefault{
+		addressMap: map[string][]*udpMuxedConn{},
+		params:     params,
+		connsIPv4:  make(map[string]*udpMuxedConn),
+		connsIPv6:  make(map[string]*udpMuxedConn),
+		closedChan: make(chan struct{}, 1),
 		pool: &sync.Pool{
 			New: func() interface{} {
 				// big enough buffer to fit both packet and address
@@ -175,15 +171,15 @@ func NewSingleSocketUDPMux(params Params) *SingleSocketUDPMux {
 	return mux
 }
 
-func (m *SingleSocketUDPMux) updateLocalAddresses() {
+func (m *UDPMuxDefault) updateLocalAddresses() {
 	var localAddrsForUnspecified []net.Addr
 	if addr, ok := m.params.UDPConn.LocalAddr().(*net.UDPAddr); !ok {
 		m.params.Logger.Errorf("LocalAddr is not a net.UDPAddr, got %T", m.params.UDPConn.LocalAddr())
 	} else if ok && addr.IP.IsUnspecified() {
 		// For unspecified addresses, the correct behavior is to return errListenUnspecified, but
 		// it will break the applications that are already using unspecified UDP connection
-		// with SingleSocketUDPMux, so print a warn log and create a local address list for mux.
-		m.params.Logger.Warn("SingleSocketUDPMux should not listening on unspecified address, use NewMultiUDPMuxFromPort instead")
+		// with UDPMuxDefault, so print a warn log and create a local address list for mux.
+		m.params.Logger.Warn("UDPMuxDefault should not listening on unspecified address, use NewMultiUDPMuxFromPort instead")
 		var networks []ice.NetworkType
 		switch {
 
@@ -220,13 +216,13 @@ func (m *SingleSocketUDPMux) updateLocalAddresses() {
 	m.mu.Unlock()
 }
 
-// LocalAddr returns the listening address of this SingleSocketUDPMux
-func (m *SingleSocketUDPMux) LocalAddr() net.Addr {
+// LocalAddr returns the listening address of this UDPMuxDefault
+func (m *UDPMuxDefault) LocalAddr() net.Addr {
 	return m.params.UDPConn.LocalAddr()
 }
 
 // GetListenAddresses returns the list of addresses that this mux is listening on
-func (m *SingleSocketUDPMux) GetListenAddresses() []net.Addr {
+func (m *UDPMuxDefault) GetListenAddresses() []net.Addr {
 	m.updateLocalAddresses()
 
 	m.mu.Lock()
@@ -240,7 +236,7 @@ func (m *SingleSocketUDPMux) GetListenAddresses() []net.Addr {
 
 // GetConn returns a PacketConn given the connection's ufrag and network address
 // creates the connection if an existing one can't be found
-func (m *SingleSocketUDPMux) GetConn(ufrag string, addr net.Addr, candidateID string) (net.PacketConn, error) {
+func (m *UDPMuxDefault) GetConn(ufrag string, addr net.Addr) (net.PacketConn, error) {
 	// don't check addr for mux using unspecified address
 	m.mu.Lock()
 	lenLocalAddrs := len(m.localAddrsForUnspecified)
@@ -264,14 +260,12 @@ func (m *SingleSocketUDPMux) GetConn(ufrag string, addr net.Addr, candidateID st
 		return conn, nil
 	}
 
-	c := m.createMuxedConn(ufrag, candidateID)
+	c := m.createMuxedConn(ufrag)
 	go func() {
 		<-c.CloseChannel()
 		m.RemoveConnByUfrag(ufrag)
 	}()
 
-	m.candidateConnMap[candidateID] = c
-
 	if isIPv6 {
 		m.connsIPv6[ufrag] = c
 	} else {
@@ -282,7 +276,7 @@ func (m *SingleSocketUDPMux) GetConn(ufrag string, addr net.Addr, candidateID st
 }
 
 // RemoveConnByUfrag stops and removes the muxed packet connection
-func (m *SingleSocketUDPMux) RemoveConnByUfrag(ufrag string) {
+func (m *UDPMuxDefault) RemoveConnByUfrag(ufrag string) {
 	removedConns := make([]*udpMuxedConn, 0, 2)
 
 	// Keep lock section small to avoid deadlock with conn lock
@@ -290,12 +284,10 @@ func (m *SingleSocketUDPMux) RemoveConnByUfrag(ufrag string) {
 	if c, ok := m.connsIPv4[ufrag]; ok {
 		delete(m.connsIPv4, ufrag)
 		removedConns = append(removedConns, c)
-		delete(m.candidateConnMap, c.GetCandidateID())
 	}
 	if c, ok := m.connsIPv6[ufrag]; ok {
 		delete(m.connsIPv6, ufrag)
 		removedConns = append(removedConns, c)
-		delete(m.candidateConnMap, c.GetCandidateID())
 	}
 	m.mu.Unlock()
 
@@ -322,7 +314,7 @@ func (m *SingleSocketUDPMux) RemoveConnByUfrag(ufrag string) {
 }
 
 // IsClosed returns true if the mux had been closed
-func (m *SingleSocketUDPMux) IsClosed() bool {
+func (m *UDPMuxDefault) IsClosed() bool {
 	select {
 	case <-m.closedChan:
 		return true
@@ -332,7 +324,7 @@ func (m *SingleSocketUDPMux) IsClosed() bool {
 }
 
 // Close the mux, no further connections could be created
-func (m *SingleSocketUDPMux) Close() error {
+func (m *UDPMuxDefault) Close() error {
 	var err error
 	m.closeOnce.Do(func() {
 		m.mu.Lock()
@@ -355,11 +347,11 @@ func (m *SingleSocketUDPMux) Close() error {
 	return err
 }
 
-func (m *SingleSocketUDPMux) writeTo(buf []byte, rAddr net.Addr) (n int, err error) {
+func (m *UDPMuxDefault) writeTo(buf []byte, rAddr net.Addr) (n int, err error) {
 	return m.params.UDPConn.WriteTo(buf, rAddr)
 }
 
-func (m *SingleSocketUDPMux) registerConnForAddress(conn *udpMuxedConn, addr string) {
+func (m *UDPMuxDefault) registerConnForAddress(conn *udpMuxedConn, addr string) {
 	if m.IsClosed() {
 		return
 	}
@@ -376,109 +368,81 @@ func (m *SingleSocketUDPMux) registerConnForAddress(conn *udpMuxedConn, addr str
 	log.Debugf("ICE: registered %s for %s", addr, conn.params.Key)
 }
 
-func (m *SingleSocketUDPMux) createMuxedConn(key string, candidateID string) *udpMuxedConn {
+func (m *UDPMuxDefault) createMuxedConn(key string) *udpMuxedConn {
 	c := newUDPMuxedConn(&udpMuxedConnParams{
-		Mux:         m,
-		Key:         key,
-		AddrPool:    m.pool,
-		LocalAddr:   m.LocalAddr(),
-		Logger:      m.params.Logger,
-		CandidateID: candidateID,
+		Mux:       m,
+		Key:       key,
+		AddrPool:  m.pool,
+		LocalAddr: m.LocalAddr(),
+		Logger:    m.params.Logger,
 	})
 	return c
 }
 
 // HandleSTUNMessage handles STUN packets and forwards them to underlying pion/ice library
-func (m *SingleSocketUDPMux) HandleSTUNMessage(msg *stun.Message, addr net.Addr) error {
+func (m *UDPMuxDefault) HandleSTUNMessage(msg *stun.Message, addr net.Addr) error {
+
 	remoteAddr, ok := addr.(*net.UDPAddr)
 	if !ok {
 		return fmt.Errorf("underlying PacketConn did not return a UDPAddr")
 	}
 
-	// Try to route to specific candidate connection first
-	if conn := m.findCandidateConnection(msg); conn != nil {
-		return conn.writePacket(msg.Raw, remoteAddr)
-	}
-
-	// Fallback: route to all possible connections
-	return m.forwardToAllConnections(msg, addr, remoteAddr)
-}
-
-// findCandidateConnection attempts to find the specific connection for a STUN message
-func (m *SingleSocketUDPMux) findCandidateConnection(msg *stun.Message) *udpMuxedConn {
-	candidatePairID, ok, err := ice.CandidatePairIDFromSTUN(msg)
-	if err != nil {
-		return nil
-	} else if !ok {
-		return nil
-	}
-
-	m.mu.Lock()
-	defer m.mu.Unlock()
-	conn, exists := m.candidateConnMap[candidatePairID.TargetCandidateID()]
-	if !exists {
-		return nil
-	}
-	return conn
-}
-
-// forwardToAllConnections forwards STUN message to all relevant connections
-func (m *SingleSocketUDPMux) forwardToAllConnections(msg *stun.Message, addr net.Addr, remoteAddr *net.UDPAddr) error {
-	var destinationConnList []*udpMuxedConn
-
-	// Add connections from address map
+	// If we have already seen this address dispatch to the appropriate destination
+	// If you are using the same socket for the Host and SRFLX candidates, it might be that there are more than one
+	// muxed connection - one for the SRFLX candidate and the other one for the HOST one.
+	// We will then forward STUN packets to each of these connections.
 	m.addressMapMu.RLock()
+	var destinationConnList []*udpMuxedConn
 	if storedConns, ok := m.addressMap[addr.String()]; ok {
 		destinationConnList = append(destinationConnList, storedConns...)
 	}
 	m.addressMapMu.RUnlock()
 
-	if conn, ok := m.findConnectionByUsername(msg, addr); ok {
-		// If we have already seen this address dispatch to the appropriate destination
-		// If you are using the same socket for the Host and SRFLX candidates, it might be that there are more than one
-		// muxed connection - one for the SRFLX candidate and the other one for the HOST one.
-		// We will then forward STUN packets to each of these connections.
-		if !m.connectionExists(conn, destinationConnList) {
-			destinationConnList = append(destinationConnList, conn)
-		}
+	var isIPv6 bool
+	if udpAddr, _ := addr.(*net.UDPAddr); udpAddr != nil && udpAddr.IP.To4() == nil {
+		isIPv6 = true
 	}
 
-	// Forward to all found connections
+	// This block is needed to discover Peer Reflexive Candidates for which we don't know the Endpoint upfront.
+	// However, we can take a username attribute from the STUN message which contains ufrag.
+	// We can use ufrag to identify the destination conn to route packet to.
+	attr, stunAttrErr := msg.Get(stun.AttrUsername)
+	if stunAttrErr == nil {
+		ufrag := strings.Split(string(attr), ":")[0]
+
+		m.mu.Lock()
+		destinationConn := m.connsIPv4[ufrag]
+		if isIPv6 {
+			destinationConn = m.connsIPv6[ufrag]
+		}
+
+		if destinationConn != nil {
+			exists := false
+			for _, conn := range destinationConnList {
+				if conn.params.Key == destinationConn.params.Key {
+					exists = true
+					break
+				}
+			}
+			if !exists {
+				destinationConnList = append(destinationConnList, destinationConn)
+			}
+		}
+		m.mu.Unlock()
+	}
+
+	// Forward STUN packets to each destination connections even thought the STUN packet might not belong there.
+	// It will be discarded by the further ICE candidate logic if so.
 	for _, conn := range destinationConnList {
 		if err := conn.writePacket(msg.Raw, remoteAddr); err != nil {
 			log.Errorf("could not write packet: %v", err)
 		}
 	}
+
 	return nil
 }
 
-// findConnectionByUsername finds connection using username attribute from STUN message
-func (m *SingleSocketUDPMux) findConnectionByUsername(msg *stun.Message, addr net.Addr) (*udpMuxedConn, bool) {
-	attr, err := msg.Get(stun.AttrUsername)
-	if err != nil {
-		return nil, false
-	}
-
-	ufrag := strings.Split(string(attr), ":")[0]
-	isIPv6 := isIPv6Address(addr)
-
-	m.mu.Lock()
-	defer m.mu.Unlock()
-
-	return m.getConn(ufrag, isIPv6)
-}
-
-// connectionExists checks if a connection already exists in the list
-func (m *SingleSocketUDPMux) connectionExists(target *udpMuxedConn, conns []*udpMuxedConn) bool {
-	for _, conn := range conns {
-		if conn.params.Key == target.params.Key {
-			return true
-		}
-	}
-	return false
-}
-
-func (m *SingleSocketUDPMux) getConn(ufrag string, isIPv6 bool) (val *udpMuxedConn, ok bool) {
+func (m *UDPMuxDefault) getConn(ufrag string, isIPv6 bool) (val *udpMuxedConn, ok bool) {
 	if isIPv6 {
 		val, ok = m.connsIPv6[ufrag]
 	} else {
@@ -487,13 +451,6 @@ func (m *SingleSocketUDPMux) getConn(ufrag string, isIPv6 bool) (val *udpMuxedCo
 	return
 }
 
-func isIPv6Address(addr net.Addr) bool {
-	if udpAddr, ok := addr.(*net.UDPAddr); ok {
-		return udpAddr.IP.To4() == nil
-	}
-	return false
-}
-
 type bufferHolder struct {
 	buf []byte
 }

client/iface/bind/udp_mux_generic.go

@@ -1,12 +1,12 @@
 //go:build !ios
 
-package udpmux
+package bind
 
 import (
-	nbnet "github.com/netbirdio/netbird/client/net"
+	nbnet "github.com/netbirdio/netbird/util/net"
 )
 
-func (m *SingleSocketUDPMux) notifyAddressRemoval(addr string) {
+func (m *UDPMuxDefault) notifyAddressRemoval(addr string) {
 	// Kernel mode: direct nbnet.PacketConn (SharedSocket wrapped with nbnet)
 	if conn, ok := m.params.UDPConn.(*nbnet.PacketConn); ok {
 		conn.RemoveAddress(addr)

client/iface/bind/udp_mux_ios.go

@@ -0,0 +1,7 @@
+//go:build ios
+
+package bind
+
+func (m *UDPMuxDefault) notifyAddressRemoval(addr string) {
+	// iOS doesn't support nbnet hooks, so this is a no-op
+}

client/iface/bind/udp_mux_universal.go

@@ -1,4 +1,4 @@
-package udpmux
+package bind
 
 /*
  Most of this code was copied from https://github.com/pion/ice and modified to fulfill NetBird's requirements.
@@ -15,10 +15,9 @@ import (
 	log "github.com/sirupsen/logrus"
 
 	"github.com/pion/logging"
-	"github.com/pion/stun/v3"
+	"github.com/pion/stun/v2"
 	"github.com/pion/transport/v3"
 
-	"github.com/netbirdio/netbird/client/iface/bufsize"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
 )
 
@@ -29,7 +28,7 @@ type FilterFn func(address netip.Addr) (bool, netip.Prefix, error)
 // UniversalUDPMuxDefault handles STUN and TURN servers packets by wrapping the original UDPConn
 // It then passes packets to the UDPMux that does the actual connection muxing.
 type UniversalUDPMuxDefault struct {
-	*SingleSocketUDPMux
+	*UDPMuxDefault
 	params UniversalUDPMuxParams
 
 	// since we have a shared socket, for srflx candidates it makes sense to have a shared mapped address across all the agents
@@ -45,7 +44,6 @@ type UniversalUDPMuxParams struct {
 	Net                   transport.Net
 	FilterFn              FilterFn
 	WGAddress             wgaddr.Address
-	MTU                   uint16
 }
 
 // NewUniversalUDPMuxDefault creates an implementation of UniversalUDPMux embedding UDPMux
@@ -72,12 +70,12 @@ func NewUniversalUDPMuxDefault(params UniversalUDPMuxParams) *UniversalUDPMuxDef
 		address:    params.WGAddress,
 	}
 
-	udpMuxParams := Params{
+	udpMuxParams := UDPMuxParams{
 		Logger:  params.Logger,
 		UDPConn: m.params.UDPConn,
 		Net:     m.params.Net,
 	}
-	m.SingleSocketUDPMux = NewSingleSocketUDPMux(udpMuxParams)
+	m.UDPMuxDefault = NewUDPMuxDefault(udpMuxParams)
 
 	return m
 }
@@ -86,7 +84,7 @@ func NewUniversalUDPMuxDefault(params UniversalUDPMuxParams) *UniversalUDPMuxDef
 // just ignore other packets printing an warning message.
 // It is a blocking method, consider running in a go routine.
 func (m *UniversalUDPMuxDefault) ReadFromConn(ctx context.Context) {
-	buf := make([]byte, m.params.MTU+bufsize.WGBufferOverhead)
+	buf := make([]byte, 1500)
 	for {
 		select {
 		case <-ctx.Done():
@@ -211,8 +209,8 @@ func (m *UniversalUDPMuxDefault) GetRelayedAddr(turnAddr net.Addr, deadline time
 
 // GetConnForURL add uniques to the muxed connection by concatenating ufrag and URL (e.g. STUN URL) to be able to support multiple STUN/TURN servers
 // and return a unique connection per server.
-func (m *UniversalUDPMuxDefault) GetConnForURL(ufrag string, url string, addr net.Addr, candidateID string) (net.PacketConn, error) {
-	return m.SingleSocketUDPMux.GetConn(fmt.Sprintf("%s%s", ufrag, url), addr, candidateID)
+func (m *UniversalUDPMuxDefault) GetConnForURL(ufrag string, url string, addr net.Addr) (net.PacketConn, error) {
+	return m.UDPMuxDefault.GetConn(fmt.Sprintf("%s%s", ufrag, url), addr)
 }
 
 // HandleSTUNMessage discovers STUN packets that carry a XOR mapped address from a STUN server.
@@ -233,7 +231,7 @@ func (m *UniversalUDPMuxDefault) HandleSTUNMessage(msg *stun.Message, addr net.A
 		}
 		return nil
 	}
-	return m.SingleSocketUDPMux.HandleSTUNMessage(msg, addr)
+	return m.UDPMuxDefault.HandleSTUNMessage(msg, addr)
 }
 
 // isXORMappedResponse indicates whether the message is a XORMappedAddress and is coming from the known STUN server.

client/iface/bind/udp_muxed_conn.go

@@ -1,4 +1,4 @@
-package udpmux
+package bind
 
 /*
  Most of this code was copied from https://github.com/pion/ice and modified to fulfill NetBird's requirements
@@ -16,12 +16,11 @@ import (
 )
 
 type udpMuxedConnParams struct {
-	Mux         *SingleSocketUDPMux
-	AddrPool    *sync.Pool
-	Key         string
-	LocalAddr   net.Addr
-	Logger      logging.LeveledLogger
-	CandidateID string
+	Mux       *UDPMuxDefault
+	AddrPool  *sync.Pool
+	Key       string
+	LocalAddr net.Addr
+	Logger    logging.LeveledLogger
 }
 
 // udpMuxedConn represents a logical packet conn for a single remote as identified by ufrag
@@ -120,10 +119,6 @@ func (c *udpMuxedConn) Close() error {
 	return err
 }
 
-func (c *udpMuxedConn) GetCandidateID() string {
-	return c.params.CandidateID
-}
-
 func (c *udpMuxedConn) isClosed() bool {
 	select {
 	case <-c.closedChan:

client/iface/bufsize/bufsize.go

@@ -1,9 +0,0 @@
-package bufsize
-
-const (
-	// WGBufferOverhead represents the additional buffer space needed beyond MTU
-	// for WireGuard packet encapsulation (WG header + UDP + IP + safety margin)
-	// Original hardcoded buffers were 1500, default MTU is 1280, so overhead = 220
-	// TODO: Calculate this properly based on actual protocol overhead instead of using hardcoded difference
-	WGBufferOverhead = 220
-)

client/iface/configurer/kernel_unix.go

@@ -73,44 +73,6 @@ func (c *KernelConfigurer) UpdatePeer(peerKey string, allowedIps []netip.Prefix,
 	return nil
 }
 
-func (c *KernelConfigurer) RemoveEndpointAddress(peerKey string) error {
-	peerKeyParsed, err := wgtypes.ParseKey(peerKey)
-	if err != nil {
-		return err
-	}
-
-	// Get the existing peer to preserve its allowed IPs
-	existingPeer, err := c.getPeer(c.deviceName, peerKey)
-	if err != nil {
-		return fmt.Errorf("get peer: %w", err)
-	}
-
-	removePeerCfg := wgtypes.PeerConfig{
-		PublicKey: peerKeyParsed,
-		Remove:    true,
-	}
-
-	if err := c.configure(wgtypes.Config{Peers: []wgtypes.PeerConfig{removePeerCfg}}); err != nil {
-		return fmt.Errorf(`error removing peer %s from interface %s: %w`, peerKey, c.deviceName, err)
-	}
-
-	//Re-add the peer without the endpoint but same AllowedIPs
-	reAddPeerCfg := wgtypes.PeerConfig{
-		PublicKey:         peerKeyParsed,
-		AllowedIPs:        existingPeer.AllowedIPs,
-		ReplaceAllowedIPs: true,
-	}
-
-	if err := c.configure(wgtypes.Config{Peers: []wgtypes.PeerConfig{reAddPeerCfg}}); err != nil {
-		return fmt.Errorf(
-			`error re-adding peer %s to interface %s with allowed IPs %v: %w`,
-			peerKey, c.deviceName, existingPeer.AllowedIPs, err,
-		)
-	}
-
-	return nil
-}
-
 func (c *KernelConfigurer) RemovePeer(peerKey string) error {
 	peerKeyParsed, err := wgtypes.ParseKey(peerKey)
 	if err != nil {

client/iface/configurer/name.go

@@ -1,4 +1,4 @@
-//go:build linux || windows || freebsd || js || wasip1
+//go:build linux || windows || freebsd
 
 package configurer
 

client/iface/configurer/uapi.go

@@ -1,4 +1,4 @@
-//go:build !windows && !js
+//go:build !windows
 
 package configurer
 

client/iface/configurer/uapi_js.go

@@ -1,23 +0,0 @@
-package configurer
-
-import (
-	"net"
-)
-
-type noopListener struct{}
-
-func (n *noopListener) Accept() (net.Conn, error) {
-	return nil, net.ErrClosed
-}
-
-func (n *noopListener) Close() error {
-	return nil
-}
-
-func (n *noopListener) Addr() net.Addr {
-	return nil
-}
-
-func openUAPI(deviceName string) (net.Listener, error) {
-	return &noopListener{}, nil
-}

client/iface/configurer/usp.go

@@ -17,8 +17,8 @@ import (
 	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
 
 	"github.com/netbirdio/netbird/client/iface/bind"
-	nbnet "github.com/netbirdio/netbird/client/net"
 	"github.com/netbirdio/netbird/monotime"
+	nbnet "github.com/netbirdio/netbird/util/net"
 )
 
 const (
@@ -106,67 +106,6 @@ func (c *WGUSPConfigurer) UpdatePeer(peerKey string, allowedIps []netip.Prefix,
 	return nil
 }
 
-func (c *WGUSPConfigurer) RemoveEndpointAddress(peerKey string) error {
-	peerKeyParsed, err := wgtypes.ParseKey(peerKey)
-	if err != nil {
-		return fmt.Errorf("parse peer key: %w", err)
-	}
-
-	ipcStr, err := c.device.IpcGet()
-	if err != nil {
-		return fmt.Errorf("get IPC config: %w", err)
-	}
-
-	// Parse current status to get allowed IPs for the peer
-	stats, err := parseStatus(c.deviceName, ipcStr)
-	if err != nil {
-		return fmt.Errorf("parse IPC config: %w", err)
-	}
-
-	var allowedIPs []net.IPNet
-	found := false
-	for _, peer := range stats.Peers {
-		if peer.PublicKey == peerKey {
-			allowedIPs = peer.AllowedIPs
-			found = true
-			break
-		}
-	}
-	if !found {
-		return fmt.Errorf("peer %s not found", peerKey)
-	}
-
-	// remove the peer from the WireGuard configuration
-	peer := wgtypes.PeerConfig{
-		PublicKey: peerKeyParsed,
-		Remove:    true,
-	}
-
-	config := wgtypes.Config{
-		Peers: []wgtypes.PeerConfig{peer},
-	}
-	if ipcErr := c.device.IpcSet(toWgUserspaceString(config)); ipcErr != nil {
-		return fmt.Errorf("failed to remove peer: %s", ipcErr)
-	}
-
-	// Build the peer config
-	peer = wgtypes.PeerConfig{
-		PublicKey:         peerKeyParsed,
-		ReplaceAllowedIPs: true,
-		AllowedIPs:        allowedIPs,
-	}
-
-	config = wgtypes.Config{
-		Peers: []wgtypes.PeerConfig{peer},
-	}
-
-	if err := c.device.IpcSet(toWgUserspaceString(config)); err != nil {
-		return fmt.Errorf("remove endpoint address: %w", err)
-	}
-
-	return nil
-}
-
 func (c *WGUSPConfigurer) RemovePeer(peerKey string) error {
 	peerKeyParsed, err := wgtypes.ParseKey(peerKey)
 	if err != nil {
@@ -455,13 +394,6 @@ func toLastHandshake(stringVar string) (time.Time, error) {
 	if err != nil {
 		return time.Time{}, fmt.Errorf("parse handshake sec: %w", err)
 	}
-
-	// If sec is 0 (Unix epoch), return zero time instead
-	// This indicates no handshake has occurred
-	if sec == 0 {
-		return time.Time{}, nil
-	}
-
 	return time.Unix(sec, 0), nil
 }
 
@@ -470,7 +402,7 @@ func toBytes(s string) (int64, error) {
 }
 
 func getFwmark() int {
-	if nbnet.AdvancedRouting() && runtime.GOOS == "linux" {
+	if nbnet.AdvancedRouting() {
 		return nbnet.ControlPlaneMark
 	}
 	return 0

client/iface/device.go

@@ -7,21 +7,19 @@ import (
 
 	wgdevice "golang.zx2c4.com/wireguard/device"
 
+	"github.com/netbirdio/netbird/client/iface/bind"
 	"github.com/netbirdio/netbird/client/iface/device"
-	"github.com/netbirdio/netbird/client/iface/udpmux"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
 )
 
 type WGTunDevice interface {
 	Create() (device.WGConfigurer, error)
-	Up() (*udpmux.UniversalUDPMuxDefault, error)
+	Up() (*bind.UniversalUDPMuxDefault, error)
 	UpdateAddr(address wgaddr.Address) error
 	WgAddress() wgaddr.Address
-	MTU() uint16
 	DeviceName() string
 	Close() error
 	FilteredDevice() *device.FilteredDevice
 	Device() *wgdevice.Device
 	GetNet() *netstack.Net
-	GetICEBind() device.EndpointManager
 }

client/iface/device/device_android.go

@@ -13,7 +13,6 @@ import (
 
 	"github.com/netbirdio/netbird/client/iface/bind"
 	"github.com/netbirdio/netbird/client/iface/configurer"
-	"github.com/netbirdio/netbird/client/iface/udpmux"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
 )
 
@@ -22,7 +21,7 @@ type WGTunDevice struct {
 	address    wgaddr.Address
 	port       int
 	key        string
-	mtu        uint16
+	mtu        int
 	iceBind    *bind.ICEBind
 	tunAdapter TunAdapter
 	disableDNS bool
@@ -30,11 +29,11 @@ type WGTunDevice struct {
 	name           string
 	device         *device.Device
 	filteredDevice *FilteredDevice
-	udpMux         *udpmux.UniversalUDPMuxDefault
+	udpMux         *bind.UniversalUDPMuxDefault
 	configurer     WGConfigurer
 }
 
-func NewTunDevice(address wgaddr.Address, port int, key string, mtu uint16, iceBind *bind.ICEBind, tunAdapter TunAdapter, disableDNS bool) *WGTunDevice {
+func NewTunDevice(address wgaddr.Address, port int, key string, mtu int, iceBind *bind.ICEBind, tunAdapter TunAdapter, disableDNS bool) *WGTunDevice {
 	return &WGTunDevice{
 		address:    address,
 		port:       port,
@@ -59,7 +58,7 @@ func (t *WGTunDevice) Create(routes []string, dns string, searchDomains []string
 		searchDomainsToString = ""
 	}
 
-	fd, err := t.tunAdapter.ConfigureInterface(t.address.String(), int(t.mtu), dns, searchDomainsToString, routesString)
+	fd, err := t.tunAdapter.ConfigureInterface(t.address.String(), t.mtu, dns, searchDomainsToString, routesString)
 	if err != nil {
 		log.Errorf("failed to create Android interface: %s", err)
 		return nil, err
@@ -89,7 +88,7 @@ func (t *WGTunDevice) Create(routes []string, dns string, searchDomains []string
 	}
 	return t.configurer, nil
 }
-func (t *WGTunDevice) Up() (*udpmux.UniversalUDPMuxDefault, error) {
+func (t *WGTunDevice) Up() (*bind.UniversalUDPMuxDefault, error) {
 	err := t.device.Up()
 	if err != nil {
 		return nil, err
@@ -138,10 +137,6 @@ func (t *WGTunDevice) WgAddress() wgaddr.Address {
 	return t.address
 }
 
-func (t *WGTunDevice) MTU() uint16 {
-	return t.mtu
-}
-
 func (t *WGTunDevice) FilteredDevice() *FilteredDevice {
 	return t.filteredDevice
 }
@@ -150,11 +145,6 @@ func (t *WGTunDevice) GetNet() *netstack.Net {
 	return nil
 }
 
-// GetICEBind returns the ICEBind instance
-func (t *WGTunDevice) GetICEBind() EndpointManager {
-	return t.iceBind
-}
-
 func routesToString(routes []string) string {
 	return strings.Join(routes, ";")
 }

client/iface/device/device_darwin.go

@@ -13,7 +13,6 @@ import (
 
 	"github.com/netbirdio/netbird/client/iface/bind"
 	"github.com/netbirdio/netbird/client/iface/configurer"
-	"github.com/netbirdio/netbird/client/iface/udpmux"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
 )
 
@@ -22,16 +21,16 @@ type TunDevice struct {
 	address wgaddr.Address
 	port    int
 	key     string
-	mtu     uint16
+	mtu     int
 	iceBind *bind.ICEBind
 
 	device         *device.Device
 	filteredDevice *FilteredDevice
-	udpMux         *udpmux.UniversalUDPMuxDefault
+	udpMux         *bind.UniversalUDPMuxDefault
 	configurer     WGConfigurer
 }
 
-func NewTunDevice(name string, address wgaddr.Address, port int, key string, mtu uint16, iceBind *bind.ICEBind) *TunDevice {
+func NewTunDevice(name string, address wgaddr.Address, port int, key string, mtu int, iceBind *bind.ICEBind) *TunDevice {
 	return &TunDevice{
 		name:    name,
 		address: address,
@@ -43,7 +42,7 @@ func NewTunDevice(name string, address wgaddr.Address, port int, key string, mtu
 }
 
 func (t *TunDevice) Create() (WGConfigurer, error) {
-	tunDevice, err := tun.CreateTUN(t.name, int(t.mtu))
+	tunDevice, err := tun.CreateTUN(t.name, t.mtu)
 	if err != nil {
 		return nil, fmt.Errorf("error creating tun device: %s", err)
 	}
@@ -72,7 +71,7 @@ func (t *TunDevice) Create() (WGConfigurer, error) {
 	return t.configurer, nil
 }
 
-func (t *TunDevice) Up() (*udpmux.UniversalUDPMuxDefault, error) {
+func (t *TunDevice) Up() (*bind.UniversalUDPMuxDefault, error) {
 	err := t.device.Up()
 	if err != nil {
 		return nil, err
@@ -112,10 +111,6 @@ func (t *TunDevice) WgAddress() wgaddr.Address {
 	return t.address
 }
 
-func (t *TunDevice) MTU() uint16 {
-	return t.mtu
-}
-
 func (t *TunDevice) DeviceName() string {
 	return t.name
 }
@@ -154,8 +149,3 @@ func (t *TunDevice) assignAddr() error {
 func (t *TunDevice) GetNet() *netstack.Net {
 	return nil
 }
-
-// GetICEBind returns the ICEBind instance
-func (t *TunDevice) GetICEBind() EndpointManager {
-	return t.iceBind
-}

client/iface/device/device_ios.go

@@ -14,7 +14,6 @@ import (
 
 	"github.com/netbirdio/netbird/client/iface/bind"
 	"github.com/netbirdio/netbird/client/iface/configurer"
-	"github.com/netbirdio/netbird/client/iface/udpmux"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
 )
 
@@ -23,23 +22,21 @@ type TunDevice struct {
 	address wgaddr.Address
 	port    int
 	key     string
-	mtu     uint16
 	iceBind *bind.ICEBind
 	tunFd   int
 
 	device         *device.Device
 	filteredDevice *FilteredDevice
-	udpMux         *udpmux.UniversalUDPMuxDefault
+	udpMux         *bind.UniversalUDPMuxDefault
 	configurer     WGConfigurer
 }
 
-func NewTunDevice(name string, address wgaddr.Address, port int, key string, mtu uint16, iceBind *bind.ICEBind, tunFd int) *TunDevice {
+func NewTunDevice(name string, address wgaddr.Address, port int, key string, iceBind *bind.ICEBind, tunFd int) *TunDevice {
 	return &TunDevice{
 		name:    name,
 		address: address,
 		port:    port,
 		key:     key,
-		mtu:     mtu,
 		iceBind: iceBind,
 		tunFd:   tunFd,
 	}
@@ -84,7 +81,7 @@ func (t *TunDevice) Create() (WGConfigurer, error) {
 	return t.configurer, nil
 }
 
-func (t *TunDevice) Up() (*udpmux.UniversalUDPMuxDefault, error) {
+func (t *TunDevice) Up() (*bind.UniversalUDPMuxDefault, error) {
 	err := t.device.Up()
 	if err != nil {
 		return nil, err
@@ -128,10 +125,6 @@ func (t *TunDevice) WgAddress() wgaddr.Address {
 	return t.address
 }
 
-func (t *TunDevice) MTU() uint16 {
-	return t.mtu
-}
-
 func (t *TunDevice) UpdateAddr(_ wgaddr.Address) error {
 	// todo implement
 	return nil
@@ -144,8 +137,3 @@ func (t *TunDevice) FilteredDevice() *FilteredDevice {
 func (t *TunDevice) GetNet() *netstack.Net {
 	return nil
 }
-
-// GetICEBind returns the ICEBind instance
-func (t *TunDevice) GetICEBind() EndpointManager {
-	return t.iceBind
-}

client/iface/device/device_kernel_unix.go

@@ -12,11 +12,11 @@ import (
 	"golang.zx2c4.com/wireguard/device"
 	"golang.zx2c4.com/wireguard/tun/netstack"
 
+	"github.com/netbirdio/netbird/client/iface/bind"
 	"github.com/netbirdio/netbird/client/iface/configurer"
-	"github.com/netbirdio/netbird/client/iface/udpmux"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
-	nbnet "github.com/netbirdio/netbird/client/net"
 	"github.com/netbirdio/netbird/sharedsock"
+	nbnet "github.com/netbirdio/netbird/util/net"
 )
 
 type TunKernelDevice struct {
@@ -24,19 +24,19 @@ type TunKernelDevice struct {
 	address      wgaddr.Address
 	wgPort       int
 	key          string
-	mtu          uint16
+	mtu          int
 	ctx          context.Context
 	ctxCancel    context.CancelFunc
 	transportNet transport.Net
 
 	link       *wgLink
 	udpMuxConn net.PacketConn
-	udpMux     *udpmux.UniversalUDPMuxDefault
+	udpMux     *bind.UniversalUDPMuxDefault
 
-	filterFn udpmux.FilterFn
+	filterFn bind.FilterFn
 }
 
-func NewKernelDevice(name string, address wgaddr.Address, wgPort int, key string, mtu uint16, transportNet transport.Net) *TunKernelDevice {
+func NewKernelDevice(name string, address wgaddr.Address, wgPort int, key string, mtu int, transportNet transport.Net) *TunKernelDevice {
 	ctx, cancel := context.WithCancel(context.Background())
 	return &TunKernelDevice{
 		ctx:          ctx,
@@ -66,7 +66,7 @@ func (t *TunKernelDevice) Create() (WGConfigurer, error) {
 	// TODO: do a MTU discovery
 	log.Debugf("setting MTU: %d interface: %s", t.mtu, t.name)
 
-	if err := link.setMTU(int(t.mtu)); err != nil {
+	if err := link.setMTU(t.mtu); err != nil {
 		return nil, fmt.Errorf("set mtu: %w", err)
 	}
 
@@ -79,7 +79,7 @@ func (t *TunKernelDevice) Create() (WGConfigurer, error) {
 	return configurer, nil
 }
 
-func (t *TunKernelDevice) Up() (*udpmux.UniversalUDPMuxDefault, error) {
+func (t *TunKernelDevice) Up() (*bind.UniversalUDPMuxDefault, error) {
 	if t.udpMux != nil {
 		return t.udpMux, nil
 	}
@@ -96,19 +96,23 @@ func (t *TunKernelDevice) Up() (*udpmux.UniversalUDPMuxDefault, error) {
 		return nil, err
 	}
 
-	rawSock, err := sharedsock.Listen(t.wgPort, sharedsock.NewIncomingSTUNFilter(), t.mtu)
+	rawSock, err := sharedsock.Listen(t.wgPort, sharedsock.NewIncomingSTUNFilter())
 	if err != nil {
 		return nil, err
 	}
 
-	bindParams := udpmux.UniversalUDPMuxParams{
-		UDPConn:   nbnet.WrapPacketConn(rawSock),
+	var udpConn net.PacketConn = rawSock
+	if !nbnet.AdvancedRouting() {
+		udpConn = nbnet.WrapPacketConn(rawSock)
+	}
+
+	bindParams := bind.UniversalUDPMuxParams{
+		UDPConn:   udpConn,
 		Net:       t.transportNet,
 		FilterFn:  t.filterFn,
 		WGAddress: t.address,
-		MTU:       t.mtu,
 	}
-	mux := udpmux.NewUniversalUDPMuxDefault(bindParams)
+	mux := bind.NewUniversalUDPMuxDefault(bindParams)
 	go mux.ReadFromConn(t.ctx)
 	t.udpMuxConn = rawSock
 	t.udpMux = mux
@@ -154,10 +158,6 @@ func (t *TunKernelDevice) WgAddress() wgaddr.Address {
 	return t.address
 }
 
-func (t *TunKernelDevice) MTU() uint16 {
-	return t.mtu
-}
-
 func (t *TunKernelDevice) DeviceName() string {
 	return t.name
 }
@@ -179,8 +179,3 @@ func (t *TunKernelDevice) assignAddr() error {
 func (t *TunKernelDevice) GetNet() *netstack.Net {
 	return nil
 }
-
-// GetICEBind returns nil for kernel mode devices
-func (t *TunKernelDevice) GetICEBind() EndpointManager {
-	return nil
-}

client/iface/device/device_netstack.go

@@ -1,48 +1,41 @@
+//go:build !android
+// +build !android
+
 package device
 
 import (
-	"errors"
 	"fmt"
 
 	log "github.com/sirupsen/logrus"
-	"golang.zx2c4.com/wireguard/conn"
 	"golang.zx2c4.com/wireguard/device"
 	"golang.zx2c4.com/wireguard/tun/netstack"
 
 	"github.com/netbirdio/netbird/client/iface/bind"
 	"github.com/netbirdio/netbird/client/iface/configurer"
 	nbnetstack "github.com/netbirdio/netbird/client/iface/netstack"
-	"github.com/netbirdio/netbird/client/iface/udpmux"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
-	nbnet "github.com/netbirdio/netbird/client/net"
+	nbnet "github.com/netbirdio/netbird/util/net"
 )
 
-type Bind interface {
-	conn.Bind
-	GetICEMux() (*udpmux.UniversalUDPMuxDefault, error)
-	ActivityRecorder() *bind.ActivityRecorder
-	EndpointManager
-}
-
 type TunNetstackDevice struct {
 	name          string
 	address       wgaddr.Address
 	port          int
 	key           string
-	mtu           uint16
+	mtu           int
 	listenAddress string
-	bind          Bind
+	iceBind       *bind.ICEBind
 
 	device         *device.Device
 	filteredDevice *FilteredDevice
 	nsTun          *nbnetstack.NetStackTun
-	udpMux         *udpmux.UniversalUDPMuxDefault
+	udpMux         *bind.UniversalUDPMuxDefault
 	configurer     WGConfigurer
 
 	net *netstack.Net
 }
 
-func NewNetstackDevice(name string, address wgaddr.Address, wgPort int, key string, mtu uint16, bind Bind, listenAddress string) *TunNetstackDevice {
+func NewNetstackDevice(name string, address wgaddr.Address, wgPort int, key string, mtu int, iceBind *bind.ICEBind, listenAddress string) *TunNetstackDevice {
 	return &TunNetstackDevice{
 		name:          name,
 		address:       address,
@@ -50,11 +43,11 @@ func NewNetstackDevice(name string, address wgaddr.Address, wgPort int, key stri
 		key:           key,
 		mtu:           mtu,
 		listenAddress: listenAddress,
-		bind:          bind,
+		iceBind:       iceBind,
 	}
 }
 
-func (t *TunNetstackDevice) create() (WGConfigurer, error) {
+func (t *TunNetstackDevice) Create() (WGConfigurer, error) {
 	log.Info("create nbnetstack tun interface")
 
 	// TODO: get from service listener runtime IP
@@ -64,7 +57,7 @@ func (t *TunNetstackDevice) create() (WGConfigurer, error) {
 	}
 
 	log.Debugf("netstack using address: %s", t.address.IP)
-	t.nsTun = nbnetstack.NewNetStackTun(t.listenAddress, t.address.IP, dnsAddr, int(t.mtu))
+	t.nsTun = nbnetstack.NewNetStackTun(t.listenAddress, t.address.IP, dnsAddr, t.mtu)
 	log.Debugf("netstack using dns address: %s", dnsAddr)
 	tunIface, net, err := t.nsTun.Create()
 	if err != nil {
@@ -75,11 +68,11 @@ func (t *TunNetstackDevice) create() (WGConfigurer, error) {
 
 	t.device = device.NewDevice(
 		t.filteredDevice,
-		t.bind,
+		t.iceBind,
 		device.NewLogger(wgLogLevel(), "[netbird] "),
 	)
 
-	t.configurer = configurer.NewUSPConfigurer(t.device, t.name, t.bind.ActivityRecorder())
+	t.configurer = configurer.NewUSPConfigurer(t.device, t.name, t.iceBind.ActivityRecorder())
 	err = t.configurer.ConfigureInterface(t.key, t.port)
 	if err != nil {
 		_ = tunIface.Close()
@@ -90,7 +83,7 @@ func (t *TunNetstackDevice) create() (WGConfigurer, error) {
 	return t.configurer, nil
 }
 
-func (t *TunNetstackDevice) Up() (*udpmux.UniversalUDPMuxDefault, error) {
+func (t *TunNetstackDevice) Up() (*bind.UniversalUDPMuxDefault, error) {
 	if t.device == nil {
 		return nil, fmt.Errorf("device is not ready yet")
 	}
@@ -100,15 +93,11 @@ func (t *TunNetstackDevice) Up() (*udpmux.UniversalUDPMuxDefault, error) {
 		return nil, err
 	}
 
-	udpMux, err := t.bind.GetICEMux()
-	if err != nil && !errors.Is(err, bind.ErrUDPMUXNotSupported) {
+	udpMux, err := t.iceBind.GetICEMux()
+	if err != nil {
 		return nil, err
 	}
-
-	if udpMux != nil {
-		t.udpMux = udpMux
-	}
-
+	t.udpMux = udpMux
 	log.Debugf("netstack device is ready to use")
 	return udpMux, nil
 }
@@ -136,10 +125,6 @@ func (t *TunNetstackDevice) WgAddress() wgaddr.Address {
 	return t.address
 }
 
-func (t *TunNetstackDevice) MTU() uint16 {
-	return t.mtu
-}
-
 func (t *TunNetstackDevice) DeviceName() string {
 	return t.name
 }
@@ -156,8 +141,3 @@ func (t *TunNetstackDevice) Device() *device.Device {
 func (t *TunNetstackDevice) GetNet() *netstack.Net {
 	return t.net
 }
-
-// GetICEBind returns the bind instance
-func (t *TunNetstackDevice) GetICEBind() EndpointManager {
-	return t.bind
-}

client/iface/device/device_netstack_android.go

@@ -1,7 +0,0 @@
-//go:build android
-
-package device
-
-func (t *TunNetstackDevice) Create(routes []string, dns string, searchDomains []string) (WGConfigurer, error) {
-	return t.create()
-}

client/iface/device/device_netstack_generic.go

@@ -1,7 +0,0 @@
-//go:build !android
-
-package device
-
-func (t *TunNetstackDevice) Create() (WGConfigurer, error) {
-	return t.create()
-}

client/iface/device/device_netstack_test.go

@@ -1,27 +0,0 @@
-package device
-
-import (
-	"testing"
-
-	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
-
-	"github.com/netbirdio/netbird/client/iface/bind"
-	"github.com/netbirdio/netbird/client/iface/netstack"
-	"github.com/netbirdio/netbird/client/iface/wgaddr"
-)
-
-func TestNewNetstackDevice(t *testing.T) {
-	privateKey, _ := wgtypes.GeneratePrivateKey()
-	wgAddress, _ := wgaddr.ParseWGAddress("1.2.3.4/24")
-
-	relayBind := bind.NewRelayBindJS()
-	nsTun := NewNetstackDevice("wtx", wgAddress, 1234, privateKey.String(), 1500, relayBind, netstack.ListenAddr())
-
-	cfgr, err := nsTun.Create()
-	if err != nil {
-		t.Fatalf("failed to create netstack device: %v", err)
-	}
-	if cfgr == nil {
-		t.Fatal("expected non-nil configurer")
-	}
-}

client/iface/device/device_usp_unix.go

@@ -12,7 +12,6 @@ import (
 
 	"github.com/netbirdio/netbird/client/iface/bind"
 	"github.com/netbirdio/netbird/client/iface/configurer"
-	"github.com/netbirdio/netbird/client/iface/udpmux"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
 )
 
@@ -21,16 +20,16 @@ type USPDevice struct {
 	address wgaddr.Address
 	port    int
 	key     string
-	mtu     uint16
+	mtu     int
 	iceBind *bind.ICEBind
 
 	device         *device.Device
 	filteredDevice *FilteredDevice
-	udpMux         *udpmux.UniversalUDPMuxDefault
+	udpMux         *bind.UniversalUDPMuxDefault
 	configurer     WGConfigurer
 }
 
-func NewUSPDevice(name string, address wgaddr.Address, port int, key string, mtu uint16, iceBind *bind.ICEBind) *USPDevice {
+func NewUSPDevice(name string, address wgaddr.Address, port int, key string, mtu int, iceBind *bind.ICEBind) *USPDevice {
 	log.Infof("using userspace bind mode")
 
 	return &USPDevice{
@@ -45,9 +44,9 @@ func NewUSPDevice(name string, address wgaddr.Address, port int, key string, mtu
 
 func (t *USPDevice) Create() (WGConfigurer, error) {
 	log.Info("create tun interface")
-	tunIface, err := tun.CreateTUN(t.name, int(t.mtu))
+	tunIface, err := tun.CreateTUN(t.name, t.mtu)
 	if err != nil {
-		log.Debugf("failed to create tun interface (%s, %d): %s", t.name, int(t.mtu), err)
+		log.Debugf("failed to create tun interface (%s, %d): %s", t.name, t.mtu, err)
 		return nil, fmt.Errorf("error creating tun device: %s", err)
 	}
 	t.filteredDevice = newDeviceFilter(tunIface)
@@ -75,7 +74,7 @@ func (t *USPDevice) Create() (WGConfigurer, error) {
 	return t.configurer, nil
 }
 
-func (t *USPDevice) Up() (*udpmux.UniversalUDPMuxDefault, error) {
+func (t *USPDevice) Up() (*bind.UniversalUDPMuxDefault, error) {
 	if t.device == nil {
 		return nil, fmt.Errorf("device is not ready yet")
 	}
@@ -119,10 +118,6 @@ func (t *USPDevice) WgAddress() wgaddr.Address {
 	return t.address
 }
 
-func (t *USPDevice) MTU() uint16 {
-	return t.mtu
-}
-
 func (t *USPDevice) DeviceName() string {
 	return t.name
 }
@@ -146,8 +141,3 @@ func (t *USPDevice) assignAddr() error {
 func (t *USPDevice) GetNet() *netstack.Net {
 	return nil
 }
-
-// GetICEBind returns the ICEBind instance
-func (t *USPDevice) GetICEBind() EndpointManager {
-	return t.iceBind
-}

client/iface/device/device_windows.go

@@ -13,7 +13,6 @@ import (
 
 	"github.com/netbirdio/netbird/client/iface/bind"
 	"github.com/netbirdio/netbird/client/iface/configurer"
-	"github.com/netbirdio/netbird/client/iface/udpmux"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
 )
 
@@ -24,17 +23,17 @@ type TunDevice struct {
 	address wgaddr.Address
 	port    int
 	key     string
-	mtu     uint16
+	mtu     int
 	iceBind *bind.ICEBind
 
 	device          *device.Device
 	nativeTunDevice *tun.NativeTun
 	filteredDevice  *FilteredDevice
-	udpMux          *udpmux.UniversalUDPMuxDefault
+	udpMux          *bind.UniversalUDPMuxDefault
 	configurer      WGConfigurer
 }
 
-func NewTunDevice(name string, address wgaddr.Address, port int, key string, mtu uint16, iceBind *bind.ICEBind) *TunDevice {
+func NewTunDevice(name string, address wgaddr.Address, port int, key string, mtu int, iceBind *bind.ICEBind) *TunDevice {
 	return &TunDevice{
 		name:    name,
 		address: address,
@@ -60,7 +59,7 @@ func (t *TunDevice) Create() (WGConfigurer, error) {
 		return nil, err
 	}
 	log.Info("create tun interface")
-	tunDevice, err := tun.CreateTUNWithRequestedGUID(t.name, &guid, int(t.mtu))
+	tunDevice, err := tun.CreateTUNWithRequestedGUID(t.name, &guid, t.mtu)
 	if err != nil {
 		return nil, fmt.Errorf("error creating tun device: %s", err)
 	}
@@ -105,7 +104,7 @@ func (t *TunDevice) Create() (WGConfigurer, error) {
 	return t.configurer, nil
 }
 
-func (t *TunDevice) Up() (*udpmux.UniversalUDPMuxDefault, error) {
+func (t *TunDevice) Up() (*bind.UniversalUDPMuxDefault, error) {
 	err := t.device.Up()
 	if err != nil {
 		return nil, err
@@ -145,10 +144,6 @@ func (t *TunDevice) WgAddress() wgaddr.Address {
 	return t.address
 }
 
-func (t *TunDevice) MTU() uint16 {
-	return t.mtu
-}
-
 func (t *TunDevice) DeviceName() string {
 	return t.name
 }
@@ -185,8 +180,3 @@ func (t *TunDevice) assignAddr() error {
 func (t *TunDevice) GetNet() *netstack.Net {
 	return nil
 }
-
-// GetICEBind returns the ICEBind instance
-func (t *TunDevice) GetICEBind() EndpointManager {
-	return t.iceBind
-}

client/iface/device/endpoint_manager.go

@@ -1,13 +0,0 @@
-package device
-
-import (
-	"net"
-	"net/netip"
-)
-
-// EndpointManager manages fake IP to connection mappings for userspace bind implementations.
-// Implemented by bind.ICEBind and bind.RelayBindJS.
-type EndpointManager interface {
-	SetEndpoint(fakeIP netip.Addr, conn net.Conn)
-	RemoveEndpoint(fakeIP netip.Addr)
-}

client/iface/device/interface.go

@@ -21,5 +21,4 @@ type WGConfigurer interface {
 	GetStats() (map[string]configurer.WGStats, error)
 	FullStats() (*configurer.Stats, error)
 	LastActivities() map[string]monotime.Time
-	RemoveEndpointAddress(peerKey string) error
 }

client/iface/device_android.go

@@ -5,21 +5,19 @@ import (
 
 	"golang.zx2c4.com/wireguard/tun/netstack"
 
+	"github.com/netbirdio/netbird/client/iface/bind"
 	"github.com/netbirdio/netbird/client/iface/device"
-	"github.com/netbirdio/netbird/client/iface/udpmux"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
 )
 
 type WGTunDevice interface {
 	Create(routes []string, dns string, searchDomains []string) (device.WGConfigurer, error)
-	Up() (*udpmux.UniversalUDPMuxDefault, error)
+	Up() (*bind.UniversalUDPMuxDefault, error)
 	UpdateAddr(address wgaddr.Address) error
 	WgAddress() wgaddr.Address
-	MTU() uint16
 	DeviceName() string
 	Close() error
 	FilteredDevice() *device.FilteredDevice
 	Device() *wgdevice.Device
 	GetNet() *netstack.Net
-	GetICEBind() device.EndpointManager
 }