[management] fix network map dns filter (#4547)

* [client] Add WireGuard interface lifecycle monitoring

.github/workflows/docs-ack.yml

@@ -16,19 +16,29 @@ jobs:
     steps:
       - name: Read PR body
         id: body
+        shell: bash
         run: |
-          BODY=$(jq -r '.pull_request.body // ""' "$GITHUB_EVENT_PATH")
-          echo "body<<EOF" >> $GITHUB_OUTPUT
-          echo "$BODY" >> $GITHUB_OUTPUT
-          echo "EOF" >> $GITHUB_OUTPUT
+          set -euo pipefail
+          BODY_B64=$(jq -r '.pull_request.body // "" | @base64' "$GITHUB_EVENT_PATH")
+          {
+            echo "body_b64=$BODY_B64"
+          } >> "$GITHUB_OUTPUT"
 
       - name: Validate checkbox selection
         id: validate
+        shell: bash
+        env:
+          BODY_B64: ${{ steps.body.outputs.body_b64 }}
         run: |
-          body='${{ steps.body.outputs.body }}'
+          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)
 
-          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'."
@@ -41,30 +51,35 @@ 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: ${{ steps.body.outputs.body_b64 }}
         run: |
-          body='${{ steps.body.outputs.body }}'
+          set -euo pipefail
+          body="$(printf '%s' "$BODY_B64" | base64 -d)"
 
           # Strictly require HTTPS and that it's a PR in netbirdio/docs
-          # 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)
+          # 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)"
 
-          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=$(echo "$url" | sed -E 's#.*/pull/([0-9]+)$#\1#')
-          echo "url=$url" >> $GITHUB_OUTPUT
-          echo "pr_number=$pr_number" >> $GITHUB_OUTPUT
+          pr_number="$(printf '%s' "$url" | sed -E 's#.*/pull/([0-9]+)$#\1#')"
+          {
+            echo "url=$url"
+            echo "pr_number=$pr_number"
+          } >> "$GITHUB_OUTPUT"
 
       - name: Verify docs PR exists (and is open or merged)
         if: steps.validate.outputs.mode == 'added'

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

@@ -217,7 +217,7 @@ jobs:
           - arch: "386"
             raceFlag: ""
           - arch: "amd64"
-            raceFlag: ""
+            raceFlag: "-race"
     runs-on: ubuntu-22.04
     steps:
       - name: Install Go
@@ -382,6 +382,32 @@ 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 $PWD/prometheus.yml:/etc/prometheus/prometheus.yml \
+            -p 9090:9090 \
+            prom/prometheus
       - name: Install Go
         uses: actions/setup-go@v5
         with:
@@ -428,9 +454,10 @@ jobs:
           CGO_ENABLED=1 GOARCH=${{ 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' \
-          -timeout 20m ./management/... ./shared/management/...
+          -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)
 
   api_benchmark:
     name: "Management / Benchmark (API)"
@@ -521,7 +548,7 @@ jobs:
             -run=^$ \
             -bench=. \
             -exec 'sudo --preserve-env=CI,NETBIRD_STORE_ENGINE,GIT_BRANCH,GITHUB_RUN_ID' \
-            -timeout 20m ./management/... ./shared/management/...
+            -timeout 20m ./management/server/http/...
 
   api_integration_test:
     name: "Management / Integration"
@@ -571,4 +598,4 @@ jobs:
           CI=true \
           go test -tags=integration \
           -exec 'sudo --preserve-env=CI,NETBIRD_STORE_ENGINE' \
-          -timeout 20m ./management/... ./shared/management/...
+          -timeout 20m ./management/server/http/...

.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' })" >> $env:GITHUB_ENV
+      - run: echo "files=$(go list ./... | ForEach-Object { $_ } | Where-Object { $_ -notmatch '/management' } | Where-Object { $_ -notmatch '/relay' } | Where-Object { $_ -notmatch '/signal' })" >> $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/release.yml

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

README.md

@@ -1,3 +1,4 @@
+
 <div align="center">
 <br/>
   <br/>
@@ -52,7 +53,7 @@
 
 ### Open Source Network Security in a Single Platform
 
-<img width="1188" alt="centralized-network-management 1" src="https://github.com/user-attachments/assets/c28cc8e4-15d2-4d2f-bb97-a6433db39d56" />
+https://github.com/user-attachments/assets/10cec749-bb56-4ab3-97af-4e38850108d2
 
 ### 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

@@ -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="1"
+    NB_ENTRYPOINT_LOGIN_TIMEOUT="5"
 
 ENTRYPOINT [ "/usr/local/bin/netbird-entrypoint.sh" ]
 

client/android/client.go

@@ -4,6 +4,7 @@ package android
 
 import (
 	"context"
+	"os"
 	"slices"
 	"sync"
 
@@ -18,7 +19,7 @@ import (
 	"github.com/netbirdio/netbird/client/internal/stdnet"
 	"github.com/netbirdio/netbird/client/system"
 	"github.com/netbirdio/netbird/formatter"
-	"github.com/netbirdio/netbird/util/net"
+	"github.com/netbirdio/netbird/client/net"
 )
 
 // ConnectionListener export internal Listener for mobile
@@ -83,7 +84,8 @@ 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) error {
+func (c *Client) Run(urlOpener URLOpener, dns *DNSList, dnsReadyListener DnsReadyListener, envList *EnvList) error {
+	exportEnvList(envList)
 	cfg, err := profilemanager.UpdateOrCreateConfig(profilemanager.ConfigInput{
 		ConfigPath: c.cfgFile,
 	})
@@ -118,7 +120,8 @@ 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) error {
+func (c *Client) RunWithoutLogin(dns *DNSList, dnsReadyListener DnsReadyListener, envList *EnvList) error {
+	exportEnvList(envList)
 	cfg, err := profilemanager.UpdateOrCreateConfig(profilemanager.ConfigInput{
 		ConfigPath: c.cfgFile,
 	})
@@ -249,3 +252,14 @@ 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

@@ -0,0 +1,32 @@
+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

@@ -33,6 +33,7 @@ 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
@@ -181,6 +182,11 @@ 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
 		}

client/cmd/down.go

@@ -27,7 +27,7 @@ var downCmd = &cobra.Command{
 			return err
 		}
 
-		ctx, cancel := context.WithTimeout(context.Background(), time.Second*7)
+		ctx, cancel := context.WithTimeout(context.Background(), time.Second*20)
 		defer cancel()
 
 		conn, err := DialClientGRPCServer(ctx, daemonAddr)

client/cmd/login.go

@@ -227,7 +227,7 @@ func doForegroundLogin(ctx context.Context, cmd *cobra.Command, setupKey string,
 	}
 
 	// update host's static platform and system information
-	system.UpdateStaticInfo()
+	system.UpdateStaticInfoAsync()
 
 	configFilePath, err := activeProf.FilePath()
 	if err != nil {

client/cmd/root.go

@@ -39,6 +39,7 @@ const (
 	extraIFaceBlackListFlag  = "extra-iface-blacklist"
 	dnsRouteIntervalFlag     = "dns-router-interval"
 	enableLazyConnectionFlag = "enable-lazy-connection"
+	mtuFlag                  = "mtu"
 )
 
 var (
@@ -72,6 +73,7 @@ var (
 	anonymizeFlag           bool
 	dnsRouteInterval        time.Duration
 	lazyConnEnabled         bool
+	mtu                     uint16
 	profilesDisabled        bool
 	updateSettingsDisabled  bool
 
@@ -229,7 +231,7 @@ 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*3)
+	ctx, cancel := context.WithTimeout(ctx, time.Second*10)
 	defer cancel()
 
 	return grpc.DialContext(

client/cmd/root_test.go

@@ -54,6 +54,7 @@ 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_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.UpdateStaticInfo()
+	system.UpdateStaticInfoAsync()
 
 	// in any case, even if configuration does not exists we run daemon to serve CLI gRPC API.
 	p.serv = grpc.NewServer()

client/cmd/testutil_test.go

@@ -9,29 +9,26 @@ import (
 	"github.com/golang/mock/gomock"
 	"github.com/stretchr/testify/require"
 	"go.opentelemetry.io/otel"
+	"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/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"
-	mgmt "github.com/netbirdio/netbird/management/server"
 	mgmtProto "github.com/netbirdio/netbird/shared/management/proto"
 	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 {
@@ -90,15 +87,20 @@ func startManagement(t *testing.T, config *config.Config, testFile string) (*grp
 	if err != nil {
 		return nil, nil
 	}
-	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)
+	peersmanager := peers.NewManager(store, permissionsManagerMock)
+	settingsManagerMock := settings.NewMockManager(ctrl)
+
+	iv, _ := integrations.NewIntegratedValidator(context.Background(), peersmanager, settingsManagerMock, eventStore)
+
+	metrics, err := telemetry.NewDefaultAppMetrics(context.Background())
+	require.NoError(t, err)
+
+	settingsMockManager := settings.NewMockManager(ctrl)
 	groupsManager := groups.NewManagerMock()
 
 	settingsMockManager.EXPECT().

client/cmd/up.go

@@ -63,6 +63,7 @@ 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.`,
@@ -229,7 +230,9 @@ func runInDaemonMode(ctx context.Context, cmd *cobra.Command, pm *profilemanager
 
 	client := proto.NewDaemonServiceClient(conn)
 
-	status, err := client.Status(ctx, &proto.StatusRequest{})
+	status, err := client.Status(ctx, &proto.StatusRequest{
+		WaitForReady: func() *bool { b := true; return &b }(),
+	})
 	if err != nil {
 		return fmt.Errorf("unable to get daemon status: %v", err)
 	}
@@ -357,6 +360,11 @@ 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
 	}
@@ -436,6 +444,13 @@ 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
 	}
@@ -533,6 +548,14 @@ 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/embed/embed.go

@@ -135,7 +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{}, 1)
+	run := make(chan struct{})
 	clientErr := make(chan error, 1)
 	go func() {
 		if err := client.Run(run); err != 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/util/net"
+	nbnet "github.com/netbirdio/netbird/client/net"
 )
 
 const (

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/util/net"
+	nbnet "github.com/netbirdio/netbird/client/net"
 )
 
 // constants needed to manage and create iptable rules

client/firewall/iptables/router_linux_test.go

@@ -14,7 +14,7 @@ import (
 
 	firewall "github.com/netbirdio/netbird/client/firewall/manager"
 	"github.com/netbirdio/netbird/client/firewall/test"
-	nbnet "github.com/netbirdio/netbird/util/net"
+	nbnet "github.com/netbirdio/netbird/client/net"
 )
 
 func isIptablesSupported() bool {

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/util/net"
+	nbnet "github.com/netbirdio/netbird/client/net"
 )
 
 const (

client/firewall/nftables/router_linux.go

@@ -22,7 +22,7 @@ import (
 	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/util/net"
+	nbnet "github.com/netbirdio/netbird/client/net"
 )
 
 const (

client/grpc/dialer.go

@@ -20,8 +20,9 @@ import (
 	"google.golang.org/grpc/credentials/insecure"
 	"google.golang.org/grpc/keepalive"
 
+	nbnet "github.com/netbirdio/netbird/client/net"
+
 	"github.com/netbirdio/netbird/util/embeddedroots"
-	nbnet "github.com/netbirdio/netbird/util/net"
 )
 
 func WithCustomDialer() grpc.DialOption {
@@ -57,7 +58,7 @@ func Backoff(ctx context.Context) backoff.BackOff {
 	return backoff.WithContext(b, ctx)
 }
 
-func CreateConnection(addr string, tlsEnabled bool) (*grpc.ClientConn, error) {
+func CreateConnection(ctx context.Context, addr string, tlsEnabled bool) (*grpc.ClientConn, error) {
 	transportOption := grpc.WithTransportCredentials(insecure.NewCredentials())
 	if tlsEnabled {
 		certPool, err := x509.SystemCertPool()
@@ -71,7 +72,7 @@ func CreateConnection(addr string, tlsEnabled bool) (*grpc.ClientConn, error) {
 		}))
 	}
 
-	connCtx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	connCtx, cancel := context.WithTimeout(ctx, 30*time.Second)
 	defer cancel()
 
 	conn, err := grpc.DialContext(

client/iface/bind/control.go

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

client/iface/bind/ice_bind.go

@@ -8,15 +8,16 @@ import (
 	"runtime"
 	"sync"
 
-	"github.com/pion/stun/v2"
+	"github.com/pion/stun/v3"
 	"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/util/net"
+	nbnet "github.com/netbirdio/netbird/client/net"
 )
 
 type RecvMessage struct {
@@ -44,7 +45,7 @@ type ICEBind struct {
 	RecvChan chan RecvMessage
 
 	transportNet transport.Net
-	filterFn     FilterFn
+	filterFn     udpmux.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
@@ -54,12 +55,13 @@ type ICEBind struct {
 	closed       bool
 
 	muUDPMux         sync.Mutex
-	udpMux           *UniversalUDPMuxDefault
+	udpMux           *udpmux.UniversalUDPMuxDefault
 	address          wgaddr.Address
+	mtu              uint16
 	activityRecorder *ActivityRecorder
 }
 
-func NewICEBind(transportNet transport.Net, filterFn FilterFn, address wgaddr.Address) *ICEBind {
+func NewICEBind(transportNet transport.Net, filterFn udpmux.FilterFn, address wgaddr.Address, mtu uint16) *ICEBind {
 	b, _ := wgConn.NewStdNetBind().(*wgConn.StdNetBind)
 	ib := &ICEBind{
 		StdNetBind:       b,
@@ -69,6 +71,7 @@ func NewICEBind(transportNet transport.Net, filterFn FilterFn, address wgaddr.Ad
 		endpoints:        make(map[netip.Addr]net.Conn),
 		closedChan:       make(chan struct{}),
 		closed:           true,
+		mtu:              mtu,
 		address:          address,
 		activityRecorder: NewActivityRecorder(),
 	}
@@ -80,6 +83,10 @@ func NewICEBind(transportNet transport.Net, filterFn FilterFn, address wgaddr.Ad
 	return ib
 }
 
+func (s *ICEBind) MTU() uint16 {
+	return s.mtu
+}
+
 func (s *ICEBind) Open(uport uint16) ([]wgConn.ReceiveFunc, uint16, error) {
 	s.closed = false
 	s.closedChanMu.Lock()
@@ -109,7 +116,7 @@ func (s *ICEBind) ActivityRecorder() *ActivityRecorder {
 }
 
 // GetICEMux returns the ICE UDPMux that was created and used by ICEBind
-func (s *ICEBind) GetICEMux() (*UniversalUDPMuxDefault, error) {
+func (s *ICEBind) GetICEMux() (*udpmux.UniversalUDPMuxDefault, error) {
 	s.muUDPMux.Lock()
 	defer s.muUDPMux.Unlock()
 	if s.udpMux == nil {
@@ -152,12 +159,13 @@ func (s *ICEBind) createIPv4ReceiverFn(pc *ipv4.PacketConn, conn *net.UDPConn, r
 	s.muUDPMux.Lock()
 	defer s.muUDPMux.Unlock()
 
-	s.udpMux = NewUniversalUDPMuxDefault(
-		UniversalUDPMuxParams{
+	s.udpMux = udpmux.NewUniversalUDPMuxDefault(
+		udpmux.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) {

client/iface/bind/udp_mux_ios.go

@@ -1,7 +0,0 @@
-//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/bufsize/bufsize.go

@@ -0,0 +1,9 @@
+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/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 (
@@ -394,6 +394,13 @@ 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
 }
 
@@ -402,7 +409,7 @@ func toBytes(s string) (int64, error) {
 }
 
 func getFwmark() int {
-	if nbnet.AdvancedRouting() {
+	if nbnet.AdvancedRouting() && runtime.GOOS == "linux" {
 		return nbnet.ControlPlaneMark
 	}
 	return 0

client/iface/device.go

@@ -7,16 +7,17 @@ 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() (*bind.UniversalUDPMuxDefault, error)
+	Up() (*udpmux.UniversalUDPMuxDefault, error)
 	UpdateAddr(address wgaddr.Address) error
 	WgAddress() wgaddr.Address
+	MTU() uint16
 	DeviceName() string
 	Close() error
 	FilteredDevice() *device.FilteredDevice

client/iface/device/device_android.go

@@ -13,6 +13,7 @@ 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"
 )
 
@@ -21,7 +22,7 @@ type WGTunDevice struct {
 	address    wgaddr.Address
 	port       int
 	key        string
-	mtu        int
+	mtu        uint16
 	iceBind    *bind.ICEBind
 	tunAdapter TunAdapter
 	disableDNS bool
@@ -29,11 +30,11 @@ type WGTunDevice struct {
 	name           string
 	device         *device.Device
 	filteredDevice *FilteredDevice
-	udpMux         *bind.UniversalUDPMuxDefault
+	udpMux         *udpmux.UniversalUDPMuxDefault
 	configurer     WGConfigurer
 }
 
-func NewTunDevice(address wgaddr.Address, port int, key string, mtu int, iceBind *bind.ICEBind, tunAdapter TunAdapter, disableDNS bool) *WGTunDevice {
+func NewTunDevice(address wgaddr.Address, port int, key string, mtu uint16, iceBind *bind.ICEBind, tunAdapter TunAdapter, disableDNS bool) *WGTunDevice {
 	return &WGTunDevice{
 		address:    address,
 		port:       port,
@@ -58,7 +59,7 @@ func (t *WGTunDevice) Create(routes []string, dns string, searchDomains []string
 		searchDomainsToString = ""
 	}
 
-	fd, err := t.tunAdapter.ConfigureInterface(t.address.String(), t.mtu, dns, searchDomainsToString, routesString)
+	fd, err := t.tunAdapter.ConfigureInterface(t.address.String(), int(t.mtu), dns, searchDomainsToString, routesString)
 	if err != nil {
 		log.Errorf("failed to create Android interface: %s", err)
 		return nil, err
@@ -88,7 +89,7 @@ func (t *WGTunDevice) Create(routes []string, dns string, searchDomains []string
 	}
 	return t.configurer, nil
 }
-func (t *WGTunDevice) Up() (*bind.UniversalUDPMuxDefault, error) {
+func (t *WGTunDevice) Up() (*udpmux.UniversalUDPMuxDefault, error) {
 	err := t.device.Up()
 	if err != nil {
 		return nil, err
@@ -137,6 +138,10 @@ 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
 }

client/iface/device/device_darwin.go

@@ -13,6 +13,7 @@ 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 +22,16 @@ type TunDevice struct {
 	address wgaddr.Address
 	port    int
 	key     string
-	mtu     int
+	mtu     uint16
 	iceBind *bind.ICEBind
 
 	device         *device.Device
 	filteredDevice *FilteredDevice
-	udpMux         *bind.UniversalUDPMuxDefault
+	udpMux         *udpmux.UniversalUDPMuxDefault
 	configurer     WGConfigurer
 }
 
-func NewTunDevice(name string, address wgaddr.Address, port int, key string, mtu int, iceBind *bind.ICEBind) *TunDevice {
+func NewTunDevice(name string, address wgaddr.Address, port int, key string, mtu uint16, iceBind *bind.ICEBind) *TunDevice {
 	return &TunDevice{
 		name:    name,
 		address: address,
@@ -42,7 +43,7 @@ func NewTunDevice(name string, address wgaddr.Address, port int, key string, mtu
 }
 
 func (t *TunDevice) Create() (WGConfigurer, error) {
-	tunDevice, err := tun.CreateTUN(t.name, t.mtu)
+	tunDevice, err := tun.CreateTUN(t.name, int(t.mtu))
 	if err != nil {
 		return nil, fmt.Errorf("error creating tun device: %s", err)
 	}
@@ -71,7 +72,7 @@ func (t *TunDevice) Create() (WGConfigurer, error) {
 	return t.configurer, nil
 }
 
-func (t *TunDevice) Up() (*bind.UniversalUDPMuxDefault, error) {
+func (t *TunDevice) Up() (*udpmux.UniversalUDPMuxDefault, error) {
 	err := t.device.Up()
 	if err != nil {
 		return nil, err
@@ -111,6 +112,10 @@ 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
 }

client/iface/device/device_ios.go

@@ -14,6 +14,7 @@ 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"
 )
 
@@ -22,21 +23,23 @@ type TunDevice struct {
 	address wgaddr.Address
 	port    int
 	key     string
+	mtu     uint16
 	iceBind *bind.ICEBind
 	tunFd   int
 
 	device         *device.Device
 	filteredDevice *FilteredDevice
-	udpMux         *bind.UniversalUDPMuxDefault
+	udpMux         *udpmux.UniversalUDPMuxDefault
 	configurer     WGConfigurer
 }
 
-func NewTunDevice(name string, address wgaddr.Address, port int, key string, iceBind *bind.ICEBind, tunFd int) *TunDevice {
+func NewTunDevice(name string, address wgaddr.Address, port int, key string, mtu uint16, iceBind *bind.ICEBind, tunFd int) *TunDevice {
 	return &TunDevice{
 		name:    name,
 		address: address,
 		port:    port,
 		key:     key,
+		mtu:     mtu,
 		iceBind: iceBind,
 		tunFd:   tunFd,
 	}
@@ -81,7 +84,7 @@ func (t *TunDevice) Create() (WGConfigurer, error) {
 	return t.configurer, nil
 }
 
-func (t *TunDevice) Up() (*bind.UniversalUDPMuxDefault, error) {
+func (t *TunDevice) Up() (*udpmux.UniversalUDPMuxDefault, error) {
 	err := t.device.Up()
 	if err != nil {
 		return nil, err
@@ -125,6 +128,10 @@ 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

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          int
+	mtu          uint16
 	ctx          context.Context
 	ctxCancel    context.CancelFunc
 	transportNet transport.Net
 
 	link       *wgLink
 	udpMuxConn net.PacketConn
-	udpMux     *bind.UniversalUDPMuxDefault
+	udpMux     *udpmux.UniversalUDPMuxDefault
 
-	filterFn bind.FilterFn
+	filterFn udpmux.FilterFn
 }
 
-func NewKernelDevice(name string, address wgaddr.Address, wgPort int, key string, mtu int, transportNet transport.Net) *TunKernelDevice {
+func NewKernelDevice(name string, address wgaddr.Address, wgPort int, key string, mtu uint16, 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(t.mtu); err != nil {
+	if err := link.setMTU(int(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() (*bind.UniversalUDPMuxDefault, error) {
+func (t *TunKernelDevice) Up() (*udpmux.UniversalUDPMuxDefault, error) {
 	if t.udpMux != nil {
 		return t.udpMux, nil
 	}
@@ -96,23 +96,19 @@ func (t *TunKernelDevice) Up() (*bind.UniversalUDPMuxDefault, error) {
 		return nil, err
 	}
 
-	rawSock, err := sharedsock.Listen(t.wgPort, sharedsock.NewIncomingSTUNFilter())
+	rawSock, err := sharedsock.Listen(t.wgPort, sharedsock.NewIncomingSTUNFilter(), t.mtu)
 	if err != nil {
 		return nil, err
 	}
 
-	var udpConn net.PacketConn = rawSock
-	if !nbnet.AdvancedRouting() {
-		udpConn = nbnet.WrapPacketConn(rawSock)
-	}
-
-	bindParams := bind.UniversalUDPMuxParams{
-		UDPConn:   udpConn,
+	bindParams := udpmux.UniversalUDPMuxParams{
+		UDPConn:   nbnet.WrapPacketConn(rawSock),
 		Net:       t.transportNet,
 		FilterFn:  t.filterFn,
 		WGAddress: t.address,
+		MTU:       t.mtu,
 	}
-	mux := bind.NewUniversalUDPMuxDefault(bindParams)
+	mux := udpmux.NewUniversalUDPMuxDefault(bindParams)
 	go mux.ReadFromConn(t.ctx)
 	t.udpMuxConn = rawSock
 	t.udpMux = mux
@@ -158,6 +154,10 @@ 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
 }

client/iface/device/device_netstack.go

@@ -1,6 +1,3 @@
-//go:build !android
-// +build !android
-
 package device
 
 import (
@@ -13,8 +10,9 @@ import (
 	"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/util/net"
+	nbnet "github.com/netbirdio/netbird/client/net"
 )
 
 type TunNetstackDevice struct {
@@ -22,20 +20,20 @@ type TunNetstackDevice struct {
 	address       wgaddr.Address
 	port          int
 	key           string
-	mtu           int
+	mtu           uint16
 	listenAddress string
 	iceBind       *bind.ICEBind
 
 	device         *device.Device
 	filteredDevice *FilteredDevice
 	nsTun          *nbnetstack.NetStackTun
-	udpMux         *bind.UniversalUDPMuxDefault
+	udpMux         *udpmux.UniversalUDPMuxDefault
 	configurer     WGConfigurer
 
 	net *netstack.Net
 }
 
-func NewNetstackDevice(name string, address wgaddr.Address, wgPort int, key string, mtu int, iceBind *bind.ICEBind, listenAddress string) *TunNetstackDevice {
+func NewNetstackDevice(name string, address wgaddr.Address, wgPort int, key string, mtu uint16, iceBind *bind.ICEBind, listenAddress string) *TunNetstackDevice {
 	return &TunNetstackDevice{
 		name:          name,
 		address:       address,
@@ -47,7 +45,7 @@ func NewNetstackDevice(name string, address wgaddr.Address, wgPort int, key stri
 	}
 }
 
-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
@@ -57,7 +55,7 @@ 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, t.mtu)
+	t.nsTun = nbnetstack.NewNetStackTun(t.listenAddress, t.address.IP, dnsAddr, int(t.mtu))
 	log.Debugf("netstack using dns address: %s", dnsAddr)
 	tunIface, net, err := t.nsTun.Create()
 	if err != nil {
@@ -83,7 +81,7 @@ func (t *TunNetstackDevice) Create() (WGConfigurer, error) {
 	return t.configurer, nil
 }
 
-func (t *TunNetstackDevice) Up() (*bind.UniversalUDPMuxDefault, error) {
+func (t *TunNetstackDevice) Up() (*udpmux.UniversalUDPMuxDefault, error) {
 	if t.device == nil {
 		return nil, fmt.Errorf("device is not ready yet")
 	}
@@ -125,6 +123,10 @@ 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
 }

client/iface/device/device_netstack_android.go

@@ -0,0 +1,7 @@
+//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

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

client/iface/device/device_usp_unix.go

@@ -12,6 +12,7 @@ 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"
 )
 
@@ -20,16 +21,16 @@ type USPDevice struct {
 	address wgaddr.Address
 	port    int
 	key     string
-	mtu     int
+	mtu     uint16
 	iceBind *bind.ICEBind
 
 	device         *device.Device
 	filteredDevice *FilteredDevice
-	udpMux         *bind.UniversalUDPMuxDefault
+	udpMux         *udpmux.UniversalUDPMuxDefault
 	configurer     WGConfigurer
 }
 
-func NewUSPDevice(name string, address wgaddr.Address, port int, key string, mtu int, iceBind *bind.ICEBind) *USPDevice {
+func NewUSPDevice(name string, address wgaddr.Address, port int, key string, mtu uint16, iceBind *bind.ICEBind) *USPDevice {
 	log.Infof("using userspace bind mode")
 
 	return &USPDevice{
@@ -44,9 +45,9 @@ 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, t.mtu)
+	tunIface, err := tun.CreateTUN(t.name, int(t.mtu))
 	if err != nil {
-		log.Debugf("failed to create tun interface (%s, %d): %s", t.name, t.mtu, err)
+		log.Debugf("failed to create tun interface (%s, %d): %s", t.name, int(t.mtu), err)
 		return nil, fmt.Errorf("error creating tun device: %s", err)
 	}
 	t.filteredDevice = newDeviceFilter(tunIface)
@@ -74,7 +75,7 @@ func (t *USPDevice) Create() (WGConfigurer, error) {
 	return t.configurer, nil
 }
 
-func (t *USPDevice) Up() (*bind.UniversalUDPMuxDefault, error) {
+func (t *USPDevice) Up() (*udpmux.UniversalUDPMuxDefault, error) {
 	if t.device == nil {
 		return nil, fmt.Errorf("device is not ready yet")
 	}
@@ -118,6 +119,10 @@ 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
 }

client/iface/device/device_windows.go

@@ -13,6 +13,7 @@ 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"
 )
 
@@ -23,17 +24,17 @@ type TunDevice struct {
 	address wgaddr.Address
 	port    int
 	key     string
-	mtu     int
+	mtu     uint16
 	iceBind *bind.ICEBind
 
 	device          *device.Device
 	nativeTunDevice *tun.NativeTun
 	filteredDevice  *FilteredDevice
-	udpMux          *bind.UniversalUDPMuxDefault
+	udpMux          *udpmux.UniversalUDPMuxDefault
 	configurer      WGConfigurer
 }
 
-func NewTunDevice(name string, address wgaddr.Address, port int, key string, mtu int, iceBind *bind.ICEBind) *TunDevice {
+func NewTunDevice(name string, address wgaddr.Address, port int, key string, mtu uint16, iceBind *bind.ICEBind) *TunDevice {
 	return &TunDevice{
 		name:    name,
 		address: address,
@@ -59,7 +60,7 @@ func (t *TunDevice) Create() (WGConfigurer, error) {
 		return nil, err
 	}
 	log.Info("create tun interface")
-	tunDevice, err := tun.CreateTUNWithRequestedGUID(t.name, &guid, t.mtu)
+	tunDevice, err := tun.CreateTUNWithRequestedGUID(t.name, &guid, int(t.mtu))
 	if err != nil {
 		return nil, fmt.Errorf("error creating tun device: %s", err)
 	}
@@ -104,7 +105,7 @@ func (t *TunDevice) Create() (WGConfigurer, error) {
 	return t.configurer, nil
 }
 
-func (t *TunDevice) Up() (*bind.UniversalUDPMuxDefault, error) {
+func (t *TunDevice) Up() (*udpmux.UniversalUDPMuxDefault, error) {
 	err := t.device.Up()
 	if err != nil {
 		return nil, err
@@ -144,6 +145,10 @@ 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
 }

client/iface/device_android.go

@@ -5,16 +5,17 @@ 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() (*bind.UniversalUDPMuxDefault, error)
+	Up() (*udpmux.UniversalUDPMuxDefault, error)
 	UpdateAddr(address wgaddr.Address) error
 	WgAddress() wgaddr.Address
+	MTU() uint16
 	DeviceName() string
 	Close() error
 	FilteredDevice() *device.FilteredDevice

client/iface/iface.go

@@ -16,9 +16,9 @@ import (
 	wgdevice "golang.zx2c4.com/wireguard/device"
 
 	"github.com/netbirdio/netbird/client/errors"
-	"github.com/netbirdio/netbird/client/iface/bind"
 	"github.com/netbirdio/netbird/client/iface/configurer"
 	"github.com/netbirdio/netbird/client/iface/device"
+	"github.com/netbirdio/netbird/client/iface/udpmux"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
 	"github.com/netbirdio/netbird/client/iface/wgproxy"
 	"github.com/netbirdio/netbird/monotime"
@@ -26,6 +26,8 @@ import (
 
 const (
 	DefaultMTU         = 1280
+	MinMTU             = 576
+	MaxMTU             = 8192
 	DefaultWgPort      = 51820
 	WgInterfaceDefault = configurer.WgInterfaceDefault
 )
@@ -35,6 +37,17 @@ var (
 	ErrIfaceNotFound = fmt.Errorf("wireguard interface not found")
 )
 
+// ValidateMTU validates that MTU is within acceptable range
+func ValidateMTU(mtu uint16) error {
+	if mtu < MinMTU {
+		return fmt.Errorf("MTU %d below minimum (%d bytes)", mtu, MinMTU)
+	}
+	if mtu > MaxMTU {
+		return fmt.Errorf("MTU %d exceeds maximum supported size (%d bytes)", mtu, MaxMTU)
+	}
+	return nil
+}
+
 type wgProxyFactory interface {
 	GetProxy() wgproxy.Proxy
 	Free() error
@@ -45,10 +58,10 @@ type WGIFaceOpts struct {
 	Address      string
 	WGPort       int
 	WGPrivKey    string
-	MTU          int
+	MTU          uint16
 	MobileArgs   *device.MobileIFaceArguments
 	TransportNet transport.Net
-	FilterFn     bind.FilterFn
+	FilterFn     udpmux.FilterFn
 	DisableDNS   bool
 }
 
@@ -82,6 +95,10 @@ func (w *WGIface) Address() wgaddr.Address {
 	return w.tun.WgAddress()
 }
 
+func (w *WGIface) MTU() uint16 {
+	return w.tun.MTU()
+}
+
 // ToInterface returns the net.Interface for the Wireguard interface
 func (r *WGIface) ToInterface() *net.Interface {
 	name := r.tun.DeviceName()
@@ -97,7 +114,7 @@ func (r *WGIface) ToInterface() *net.Interface {
 
 // Up configures a Wireguard interface
 // The interface must exist before calling this method (e.g. call interface.Create() before)
-func (w *WGIface) Up() (*bind.UniversalUDPMuxDefault, error) {
+func (w *WGIface) Up() (*udpmux.UniversalUDPMuxDefault, error) {
 	w.mu.Lock()
 	defer w.mu.Unlock()
 

client/iface/iface_new_android.go

@@ -3,6 +3,7 @@ package iface
 import (
 	"github.com/netbirdio/netbird/client/iface/bind"
 	"github.com/netbirdio/netbird/client/iface/device"
+	"github.com/netbirdio/netbird/client/iface/netstack"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
 	"github.com/netbirdio/netbird/client/iface/wgproxy"
 )
@@ -14,7 +15,16 @@ func NewWGIFace(opts WGIFaceOpts) (*WGIface, error) {
 		return nil, err
 	}
 
-	iceBind := bind.NewICEBind(opts.TransportNet, opts.FilterFn, wgAddress)
+	iceBind := bind.NewICEBind(opts.TransportNet, opts.FilterFn, wgAddress, opts.MTU)
+
+	if netstack.IsEnabled() {
+		wgIFace := &WGIface{
+			userspaceBind:  true,
+			tun:            device.NewNetstackDevice(opts.IFaceName, wgAddress, opts.WGPort, opts.WGPrivKey, opts.MTU, iceBind, netstack.ListenAddr()),
+			wgProxyFactory: wgproxy.NewUSPFactory(iceBind),
+		}
+		return wgIFace, nil
+	}
 
 	wgIFace := &WGIface{
 		userspaceBind:  true,

client/iface/iface_new_darwin.go

@@ -17,7 +17,7 @@ func NewWGIFace(opts WGIFaceOpts) (*WGIface, error) {
 		return nil, err
 	}
 
-	iceBind := bind.NewICEBind(opts.TransportNet, opts.FilterFn, wgAddress)
+	iceBind := bind.NewICEBind(opts.TransportNet, opts.FilterFn, wgAddress, opts.MTU)
 
 	var tun WGTunDevice
 	if netstack.IsEnabled() {

client/iface/iface_new_ios.go

@@ -16,10 +16,10 @@ func NewWGIFace(opts WGIFaceOpts) (*WGIface, error) {
 		return nil, err
 	}
 
-	iceBind := bind.NewICEBind(opts.TransportNet, opts.FilterFn, wgAddress)
+	iceBind := bind.NewICEBind(opts.TransportNet, opts.FilterFn, wgAddress, opts.MTU)
 
 	wgIFace := &WGIface{
-		tun:            device.NewTunDevice(opts.IFaceName, wgAddress, opts.WGPort, opts.WGPrivKey, iceBind, opts.MobileArgs.TunFd),
+		tun:            device.NewTunDevice(opts.IFaceName, wgAddress, opts.WGPort, opts.WGPrivKey, opts.MTU, iceBind, opts.MobileArgs.TunFd),
 		userspaceBind:  true,
 		wgProxyFactory: wgproxy.NewUSPFactory(iceBind),
 	}

client/iface/iface_new_unix.go

@@ -22,7 +22,7 @@ func NewWGIFace(opts WGIFaceOpts) (*WGIface, error) {
 	wgIFace := &WGIface{}
 
 	if netstack.IsEnabled() {
-		iceBind := bind.NewICEBind(opts.TransportNet, opts.FilterFn, wgAddress)
+		iceBind := bind.NewICEBind(opts.TransportNet, opts.FilterFn, wgAddress, opts.MTU)
 		wgIFace.tun = device.NewNetstackDevice(opts.IFaceName, wgAddress, opts.WGPort, opts.WGPrivKey, opts.MTU, iceBind, netstack.ListenAddr())
 		wgIFace.userspaceBind = true
 		wgIFace.wgProxyFactory = wgproxy.NewUSPFactory(iceBind)
@@ -31,11 +31,11 @@ func NewWGIFace(opts WGIFaceOpts) (*WGIface, error) {
 
 	if device.WireGuardModuleIsLoaded() {
 		wgIFace.tun = device.NewKernelDevice(opts.IFaceName, wgAddress, opts.WGPort, opts.WGPrivKey, opts.MTU, opts.TransportNet)
-		wgIFace.wgProxyFactory = wgproxy.NewKernelFactory(opts.WGPort)
+		wgIFace.wgProxyFactory = wgproxy.NewKernelFactory(opts.WGPort, opts.MTU)
 		return wgIFace, nil
 	}
 	if device.ModuleTunIsLoaded() {
-		iceBind := bind.NewICEBind(opts.TransportNet, opts.FilterFn, wgAddress)
+		iceBind := bind.NewICEBind(opts.TransportNet, opts.FilterFn, wgAddress, opts.MTU)
 		wgIFace.tun = device.NewUSPDevice(opts.IFaceName, wgAddress, opts.WGPort, opts.WGPrivKey, opts.MTU, iceBind)
 		wgIFace.userspaceBind = true
 		wgIFace.wgProxyFactory = wgproxy.NewUSPFactory(iceBind)

client/iface/iface_new_windows.go

@@ -14,7 +14,7 @@ func NewWGIFace(opts WGIFaceOpts) (*WGIface, error) {
 	if err != nil {
 		return nil, err
 	}
-	iceBind := bind.NewICEBind(opts.TransportNet, opts.FilterFn, wgAddress)
+	iceBind := bind.NewICEBind(opts.TransportNet, opts.FilterFn, wgAddress, opts.MTU)
 
 	var tun WGTunDevice
 	if netstack.IsEnabled() {

client/iface/udpmux/conn.go

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

@@ -0,0 +1,64 @@
+// Package udpmux provides a custom implementation of a UDP multiplexer
+// that allows multiple logical ICE connections to share a single underlying
+// UDP socket. This is based on Pion's ICE library, with modifications for
+// NetBird's requirements.
+//
+// # Background
+//
+// In WebRTC and NAT traversal scenarios, ICE (Interactive Connectivity
+// Establishment) is responsible for discovering candidate network paths
+// and maintaining connectivity between peers. Each ICE connection
+// normally requires a dedicated UDP socket. However, using one socket
+// per candidate can be inefficient and difficult to manage.
+//
+// This package introduces SingleSocketUDPMux, which allows multiple ICE
+// candidate connections (muxed connections) to share a single UDP socket.
+// It handles demultiplexing of packets based on ICE ufrag values, STUN
+// attributes, and candidate IDs.
+//
+// # Usage
+//
+// The typical flow is:
+//
+//  1. Create a UDP socket (net.PacketConn).
+//  2. Construct Params with the socket and optional logger/net stack.
+//  3. Call NewSingleSocketUDPMux(params).
+//  4. For each ICE candidate ufrag, call GetConn(ufrag, addr, candidateID)
+//     to obtain a logical PacketConn.
+//  5. Use the returned PacketConn just like a normal UDP connection.
+//
+// # STUN Message Routing Logic
+//
+//		When a STUN packet arrives, the mux decides which connection should
+//		receive it using this routing logic:
+//
+//		Primary Routing: Candidate Pair ID
+//		  - Extract the candidate pair ID from the STUN message using
+//		    ice.CandidatePairIDFromSTUN(msg)
+//	   - The target candidate is the locally generated candidate that
+//	     corresponds to the connection that should handle this STUN message
+//		  - If found, use the target candidate ID to lookup the specific
+//		    connection in candidateConnMap
+//		  - Route the message directly to that connection
+//
+//		Fallback Routing: Broadcasting
+//		  When candidate pair ID is not available or lookup fails:
+//		  - Collect connections from addressMap based on source address
+//		  - Find connection using username attribute (ufrag) from STUN message
+//		  - Remove duplicate connections from the list
+//		  - Send the STUN message to all collected connections
+//
+// # Peer Reflexive Candidate Discovery
+//
+//	When a remote peer sends a STUN message from an unknown source address
+//	(from a candidate that has not been exchanged via signal), the ICE
+//	library will:
+//	  - Generate a new peer reflexive candidate for this source address
+//	  - Extract or assign a candidate ID based on the STUN message attributes
+//	  - Create a mapping between the new peer reflexive candidate ID and
+//	    the appropriate local connection
+//
+//	This discovery mechanism ensures that STUN messages from newly discovered
+//	peer reflexive candidates can be properly routed to the correct local
+//	connection without requiring fallback broadcasting.
+package udpmux

client/iface/udpmux/mux.go

@@ -1,4 +1,4 @@
-package bind
+package udpmux
 
 import (
 	"fmt"
@@ -8,9 +8,9 @@ import (
 	"strings"
 	"sync"
 
-	"github.com/pion/ice/v3"
+	"github.com/pion/ice/v4"
 	"github.com/pion/logging"
-	"github.com/pion/stun/v2"
+	"github.com/pion/stun/v3"
 	"github.com/pion/transport/v3"
 	"github.com/pion/transport/v3/stdnet"
 	log "github.com/sirupsen/logrus"
@@ -22,9 +22,9 @@ import (
 
 const receiveMTU = 8192
 
-// UDPMuxDefault is an implementation of the interface
-type UDPMuxDefault struct {
-	params UDPMuxParams
+// SingleSocketUDPMux is an implementation of the interface
+type SingleSocketUDPMux struct {
+	params Params
 
 	closedChan chan struct{}
 	closeOnce  sync.Once
@@ -32,6 +32,9 @@ type UDPMuxDefault 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
 
@@ -46,8 +49,8 @@ type UDPMuxDefault struct {
 
 const maxAddrSize = 512
 
-// UDPMuxParams are parameters for UDPMux.
-type UDPMuxParams struct {
+// Params are parameters for UDPMux.
+type Params struct {
 	Logger  logging.LeveledLogger
 	UDPConn net.PacketConn
 
@@ -147,18 +150,19 @@ func isZeros(ip net.IP) bool {
 	return true
 }
 
-// NewUDPMuxDefault creates an implementation of UDPMux
-func NewUDPMuxDefault(params UDPMuxParams) *UDPMuxDefault {
+// NewSingleSocketUDPMux creates an implementation of UDPMux
+func NewSingleSocketUDPMux(params Params) *SingleSocketUDPMux {
 	if params.Logger == nil {
 		params.Logger = getLogger()
 	}
 
-	mux := &UDPMuxDefault{
-		addressMap: map[string][]*udpMuxedConn{},
-		params:     params,
-		connsIPv4:  make(map[string]*udpMuxedConn),
-		connsIPv6:  make(map[string]*udpMuxedConn),
-		closedChan: make(chan struct{}, 1),
+	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),
 		pool: &sync.Pool{
 			New: func() interface{} {
 				// big enough buffer to fit both packet and address
@@ -171,15 +175,15 @@ func NewUDPMuxDefault(params UDPMuxParams) *UDPMuxDefault {
 	return mux
 }
 
-func (m *UDPMuxDefault) updateLocalAddresses() {
+func (m *SingleSocketUDPMux) 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 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")
+		// 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")
 		var networks []ice.NetworkType
 		switch {
 
@@ -216,13 +220,13 @@ func (m *UDPMuxDefault) updateLocalAddresses() {
 	m.mu.Unlock()
 }
 
-// LocalAddr returns the listening address of this UDPMuxDefault
-func (m *UDPMuxDefault) LocalAddr() net.Addr {
+// LocalAddr returns the listening address of this SingleSocketUDPMux
+func (m *SingleSocketUDPMux) LocalAddr() net.Addr {
 	return m.params.UDPConn.LocalAddr()
 }
 
 // GetListenAddresses returns the list of addresses that this mux is listening on
-func (m *UDPMuxDefault) GetListenAddresses() []net.Addr {
+func (m *SingleSocketUDPMux) GetListenAddresses() []net.Addr {
 	m.updateLocalAddresses()
 
 	m.mu.Lock()
@@ -236,7 +240,7 @@ func (m *UDPMuxDefault) 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 *UDPMuxDefault) GetConn(ufrag string, addr net.Addr) (net.PacketConn, error) {
+func (m *SingleSocketUDPMux) GetConn(ufrag string, addr net.Addr, candidateID string) (net.PacketConn, error) {
 	// don't check addr for mux using unspecified address
 	m.mu.Lock()
 	lenLocalAddrs := len(m.localAddrsForUnspecified)
@@ -260,12 +264,14 @@ func (m *UDPMuxDefault) GetConn(ufrag string, addr net.Addr) (net.PacketConn, er
 		return conn, nil
 	}
 
-	c := m.createMuxedConn(ufrag)
+	c := m.createMuxedConn(ufrag, candidateID)
 	go func() {
 		<-c.CloseChannel()
 		m.RemoveConnByUfrag(ufrag)
 	}()
 
+	m.candidateConnMap[candidateID] = c
+
 	if isIPv6 {
 		m.connsIPv6[ufrag] = c
 	} else {
@@ -276,7 +282,7 @@ func (m *UDPMuxDefault) GetConn(ufrag string, addr net.Addr) (net.PacketConn, er
 }
 
 // RemoveConnByUfrag stops and removes the muxed packet connection
-func (m *UDPMuxDefault) RemoveConnByUfrag(ufrag string) {
+func (m *SingleSocketUDPMux) RemoveConnByUfrag(ufrag string) {
 	removedConns := make([]*udpMuxedConn, 0, 2)
 
 	// Keep lock section small to avoid deadlock with conn lock
@@ -284,10 +290,12 @@ func (m *UDPMuxDefault) 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()
 
@@ -314,7 +322,7 @@ func (m *UDPMuxDefault) RemoveConnByUfrag(ufrag string) {
 }
 
 // IsClosed returns true if the mux had been closed
-func (m *UDPMuxDefault) IsClosed() bool {
+func (m *SingleSocketUDPMux) IsClosed() bool {
 	select {
 	case <-m.closedChan:
 		return true
@@ -324,7 +332,7 @@ func (m *UDPMuxDefault) IsClosed() bool {
 }
 
 // Close the mux, no further connections could be created
-func (m *UDPMuxDefault) Close() error {
+func (m *SingleSocketUDPMux) Close() error {
 	var err error
 	m.closeOnce.Do(func() {
 		m.mu.Lock()
@@ -347,11 +355,11 @@ func (m *UDPMuxDefault) Close() error {
 	return err
 }
 
-func (m *UDPMuxDefault) writeTo(buf []byte, rAddr net.Addr) (n int, err error) {
+func (m *SingleSocketUDPMux) writeTo(buf []byte, rAddr net.Addr) (n int, err error) {
 	return m.params.UDPConn.WriteTo(buf, rAddr)
 }
 
-func (m *UDPMuxDefault) registerConnForAddress(conn *udpMuxedConn, addr string) {
+func (m *SingleSocketUDPMux) registerConnForAddress(conn *udpMuxedConn, addr string) {
 	if m.IsClosed() {
 		return
 	}
@@ -368,81 +376,109 @@ func (m *UDPMuxDefault) registerConnForAddress(conn *udpMuxedConn, addr string)
 	log.Debugf("ICE: registered %s for %s", addr, conn.params.Key)
 }
 
-func (m *UDPMuxDefault) createMuxedConn(key string) *udpMuxedConn {
+func (m *SingleSocketUDPMux) createMuxedConn(key string, candidateID string) *udpMuxedConn {
 	c := newUDPMuxedConn(&udpMuxedConnParams{
-		Mux:       m,
-		Key:       key,
-		AddrPool:  m.pool,
-		LocalAddr: m.LocalAddr(),
-		Logger:    m.params.Logger,
+		Mux:         m,
+		Key:         key,
+		AddrPool:    m.pool,
+		LocalAddr:   m.LocalAddr(),
+		Logger:      m.params.Logger,
+		CandidateID: candidateID,
 	})
 	return c
 }
 
 // HandleSTUNMessage handles STUN packets and forwards them to underlying pion/ice library
-func (m *UDPMuxDefault) HandleSTUNMessage(msg *stun.Message, addr net.Addr) error {
-
+func (m *SingleSocketUDPMux) 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")
 	}
 
-	// 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()
+	// 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
+	m.addressMapMu.RLock()
 	if storedConns, ok := m.addressMap[addr.String()]; ok {
 		destinationConnList = append(destinationConnList, storedConns...)
 	}
 	m.addressMapMu.RUnlock()
 
-	var isIPv6 bool
-	if udpAddr, _ := addr.(*net.UDPAddr); udpAddr != nil && udpAddr.IP.To4() == nil {
-		isIPv6 = true
+	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)
+		}
 	}
 
-	// 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.
+	// Forward to all found connections
 	for _, conn := range destinationConnList {
 		if err := conn.writePacket(msg.Raw, remoteAddr); err != nil {
 			log.Errorf("could not write packet: %v", err)
 		}
 	}
-
 	return nil
 }
 
-func (m *UDPMuxDefault) getConn(ufrag string, isIPv6 bool) (val *udpMuxedConn, ok bool) {
+// 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) {
 	if isIPv6 {
 		val, ok = m.connsIPv6[ufrag]
 	} else {
@@ -451,6 +487,13 @@ func (m *UDPMuxDefault) getConn(ufrag string, isIPv6 bool) (val *udpMuxedConn, o
 	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/udpmux/mux_generic.go

@@ -1,12 +1,12 @@
 //go:build !ios
 
-package bind
+package udpmux
 
 import (
-	nbnet "github.com/netbirdio/netbird/util/net"
+	nbnet "github.com/netbirdio/netbird/client/net"
 )
 
-func (m *UDPMuxDefault) notifyAddressRemoval(addr string) {
+func (m *SingleSocketUDPMux) 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/udpmux/mux_ios.go

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

client/iface/udpmux/universal.go

@@ -1,4 +1,4 @@
-package bind
+package udpmux
 
 /*
  Most of this code was copied from https://github.com/pion/ice and modified to fulfill NetBird's requirements.
@@ -15,9 +15,10 @@ import (
 	log "github.com/sirupsen/logrus"
 
 	"github.com/pion/logging"
-	"github.com/pion/stun/v2"
+	"github.com/pion/stun/v3"
 	"github.com/pion/transport/v3"
 
+	"github.com/netbirdio/netbird/client/iface/bufsize"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
 )
 
@@ -28,7 +29,7 @@ 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 {
-	*UDPMuxDefault
+	*SingleSocketUDPMux
 	params UniversalUDPMuxParams
 
 	// since we have a shared socket, for srflx candidates it makes sense to have a shared mapped address across all the agents
@@ -44,6 +45,7 @@ type UniversalUDPMuxParams struct {
 	Net                   transport.Net
 	FilterFn              FilterFn
 	WGAddress             wgaddr.Address
+	MTU                   uint16
 }
 
 // NewUniversalUDPMuxDefault creates an implementation of UniversalUDPMux embedding UDPMux
@@ -70,12 +72,12 @@ func NewUniversalUDPMuxDefault(params UniversalUDPMuxParams) *UniversalUDPMuxDef
 		address:    params.WGAddress,
 	}
 
-	udpMuxParams := UDPMuxParams{
+	udpMuxParams := Params{
 		Logger:  params.Logger,
 		UDPConn: m.params.UDPConn,
 		Net:     m.params.Net,
 	}
-	m.UDPMuxDefault = NewUDPMuxDefault(udpMuxParams)
+	m.SingleSocketUDPMux = NewSingleSocketUDPMux(udpMuxParams)
 
 	return m
 }
@@ -84,7 +86,7 @@ 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, 1500)
+	buf := make([]byte, m.params.MTU+bufsize.WGBufferOverhead)
 	for {
 		select {
 		case <-ctx.Done():
@@ -209,8 +211,8 @@ 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) (net.PacketConn, error) {
-	return m.UDPMuxDefault.GetConn(fmt.Sprintf("%s%s", ufrag, url), addr)
+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)
 }
 
 // HandleSTUNMessage discovers STUN packets that carry a XOR mapped address from a STUN server.
@@ -231,7 +233,7 @@ func (m *UniversalUDPMuxDefault) HandleSTUNMessage(msg *stun.Message, addr net.A
 		}
 		return nil
 	}
-	return m.UDPMuxDefault.HandleSTUNMessage(msg, addr)
+	return m.SingleSocketUDPMux.HandleSTUNMessage(msg, addr)
 }
 
 // isXORMappedResponse indicates whether the message is a XORMappedAddress and is coming from the known STUN server.

client/iface/wgproxy/bind/proxy.go

@@ -12,6 +12,7 @@ import (
 	log "github.com/sirupsen/logrus"
 
 	"github.com/netbirdio/netbird/client/iface/bind"
+	"github.com/netbirdio/netbird/client/iface/bufsize"
 	"github.com/netbirdio/netbird/client/iface/wgproxy/listener"
 )
 
@@ -135,7 +136,7 @@ func (p *ProxyBind) proxyToLocal(ctx context.Context) {
 	}()
 
 	for {
-		buf := make([]byte, 1500)
+		buf := make([]byte, p.Bind.MTU()+bufsize.WGBufferOverhead)
 		n, err := p.remoteConn.Read(buf)
 		if err != nil {
 			if ctx.Err() != nil {

client/iface/wgproxy/ebpf/proxy.go

@@ -17,9 +17,10 @@ import (
 	log "github.com/sirupsen/logrus"
 
 	nberrors "github.com/netbirdio/netbird/client/errors"
+	"github.com/netbirdio/netbird/client/iface/bufsize"
 	"github.com/netbirdio/netbird/client/internal/ebpf"
 	ebpfMgr "github.com/netbirdio/netbird/client/internal/ebpf/manager"
-	nbnet "github.com/netbirdio/netbird/util/net"
+	nbnet "github.com/netbirdio/netbird/client/net"
 )
 
 const (
@@ -29,6 +30,7 @@ const (
 // WGEBPFProxy definition for proxy with EBPF support
 type WGEBPFProxy struct {
 	localWGListenPort int
+	mtu               uint16
 
 	ebpfManager   ebpfMgr.Manager
 	turnConnStore map[uint16]net.Conn
@@ -43,10 +45,11 @@ type WGEBPFProxy struct {
 }
 
 // NewWGEBPFProxy create new WGEBPFProxy instance
-func NewWGEBPFProxy(wgPort int) *WGEBPFProxy {
+func NewWGEBPFProxy(wgPort int, mtu uint16) *WGEBPFProxy {
 	log.Debugf("instantiate ebpf proxy")
 	wgProxy := &WGEBPFProxy{
 		localWGListenPort: wgPort,
+		mtu:               mtu,
 		ebpfManager:       ebpf.GetEbpfManagerInstance(),
 		turnConnStore:     make(map[uint16]net.Conn),
 	}
@@ -138,7 +141,7 @@ func (p *WGEBPFProxy) Free() error {
 // proxyToRemote read messages from local WireGuard interface and forward it to remote conn
 // From this go routine has only one instance.
 func (p *WGEBPFProxy) proxyToRemote() {
-	buf := make([]byte, 1500)
+	buf := make([]byte, p.mtu+bufsize.WGBufferOverhead)
 	for p.ctx.Err() == nil {
 		if err := p.readAndForwardPacket(buf); err != nil {
 			if p.ctx.Err() != nil {

client/iface/wgproxy/ebpf/proxy_test.go

@@ -7,7 +7,7 @@ import (
 )
 
 func TestWGEBPFProxy_connStore(t *testing.T) {
-	wgProxy := NewWGEBPFProxy(1)
+	wgProxy := NewWGEBPFProxy(1, 1280)
 
 	p, _ := wgProxy.storeTurnConn(nil)
 	if p != 1 {
@@ -27,7 +27,7 @@ func TestWGEBPFProxy_connStore(t *testing.T) {
 }
 
 func TestWGEBPFProxy_portCalculation_overflow(t *testing.T) {
-	wgProxy := NewWGEBPFProxy(1)
+	wgProxy := NewWGEBPFProxy(1, 1280)
 
 	_, _ = wgProxy.storeTurnConn(nil)
 	wgProxy.lastUsedPort = 65535
@@ -43,7 +43,7 @@ func TestWGEBPFProxy_portCalculation_overflow(t *testing.T) {
 }
 
 func TestWGEBPFProxy_portCalculation_maxConn(t *testing.T) {
-	wgProxy := NewWGEBPFProxy(1)
+	wgProxy := NewWGEBPFProxy(1, 1280)
 
 	for i := 0; i < 65535; i++ {
 		_, _ = wgProxy.storeTurnConn(nil)

client/iface/wgproxy/ebpf/wrapper.go

@@ -12,6 +12,7 @@ import (
 
 	log "github.com/sirupsen/logrus"
 
+	"github.com/netbirdio/netbird/client/iface/bufsize"
 	"github.com/netbirdio/netbird/client/iface/wgproxy/listener"
 )
 
@@ -103,7 +104,7 @@ func (e *ProxyWrapper) CloseConn() error {
 func (p *ProxyWrapper) proxyToLocal(ctx context.Context) {
 	defer p.WgeBPFProxy.removeTurnConn(uint16(p.wgEndpointAddr.Port))
 
-	buf := make([]byte, 1500)
+	buf := make([]byte, p.WgeBPFProxy.mtu+bufsize.WGBufferOverhead)
 	for {
 		n, err := p.readFromRemote(ctx, buf)
 		if err != nil {

client/iface/wgproxy/factory_kernel.go

@@ -11,16 +11,18 @@ import (
 
 type KernelFactory struct {
 	wgPort int
+	mtu    uint16
 
 	ebpfProxy *ebpf.WGEBPFProxy
 }
 
-func NewKernelFactory(wgPort int) *KernelFactory {
+func NewKernelFactory(wgPort int, mtu uint16) *KernelFactory {
 	f := &KernelFactory{
 		wgPort: wgPort,
+		mtu:    mtu,
 	}
 
-	ebpfProxy := ebpf.NewWGEBPFProxy(wgPort)
+	ebpfProxy := ebpf.NewWGEBPFProxy(wgPort, mtu)
 	if err := ebpfProxy.Listen(); err != nil {
 		log.Infof("WireGuard Proxy Factory will produce UDP proxy")
 		log.Warnf("failed to initialize ebpf proxy, fallback to user space proxy: %s", err)
@@ -33,7 +35,7 @@ func NewKernelFactory(wgPort int) *KernelFactory {
 
 func (w *KernelFactory) GetProxy() Proxy {
 	if w.ebpfProxy == nil {
-		return udpProxy.NewWGUDPProxy(w.wgPort)
+		return udpProxy.NewWGUDPProxy(w.wgPort, w.mtu)
 	}
 
 	return ebpf.NewProxyWrapper(w.ebpfProxy)

client/iface/wgproxy/factory_kernel_freebsd.go

@@ -9,19 +9,21 @@ import (
 // KernelFactory todo: check eBPF support on FreeBSD
 type KernelFactory struct {
 	wgPort int
+	mtu    uint16
 }
 
-func NewKernelFactory(wgPort int) *KernelFactory {
+func NewKernelFactory(wgPort int, mtu uint16) *KernelFactory {
 	log.Infof("WireGuard Proxy Factory will produce UDP proxy")
 	f := &KernelFactory{
 		wgPort: wgPort,
+		mtu:    mtu,
 	}
 
 	return f
 }
 
 func (w *KernelFactory) GetProxy() Proxy {
-	return udpProxy.NewWGUDPProxy(w.wgPort)
+	return udpProxy.NewWGUDPProxy(w.wgPort, w.mtu)
 }
 
 func (w *KernelFactory) Free() error {

client/iface/wgproxy/proxy_linux_test.go

@@ -16,7 +16,7 @@ func TestProxyCloseByRemoteConnEBPF(t *testing.T) {
 	}
 	ctx := context.Background()
 
-	ebpfProxy := ebpf.NewWGEBPFProxy(51831)
+	ebpfProxy := ebpf.NewWGEBPFProxy(51831, 1280)
 	if err := ebpfProxy.Listen(); err != nil {
 		t.Fatalf("failed to initialize ebpf proxy: %s", err)
 	}

client/iface/wgproxy/proxy_test.go

@@ -84,12 +84,12 @@ func TestProxyCloseByRemoteConn(t *testing.T) {
 	}{
 		{
 			name:  "userspace proxy",
-			proxy: udpProxy.NewWGUDPProxy(51830),
+			proxy: udpProxy.NewWGUDPProxy(51830, 1280),
 		},
 	}
 
 	if runtime.GOOS == "linux" && os.Getenv("GITHUB_ACTIONS") != "true" {
-		ebpfProxy := ebpf.NewWGEBPFProxy(51831)
+		ebpfProxy := ebpf.NewWGEBPFProxy(51831, 1280)
 		if err := ebpfProxy.Listen(); err != nil {
 			t.Fatalf("failed to initialize ebpf proxy: %s", err)
 		}

client/iface/wgproxy/udp/proxy.go

@@ -12,12 +12,14 @@ import (
 	log "github.com/sirupsen/logrus"
 
 	cerrors "github.com/netbirdio/netbird/client/errors"
+	"github.com/netbirdio/netbird/client/iface/bufsize"
 	"github.com/netbirdio/netbird/client/iface/wgproxy/listener"
 )
 
 // WGUDPProxy proxies
 type WGUDPProxy struct {
 	localWGListenPort int
+	mtu               uint16
 
 	remoteConn net.Conn
 	localConn  net.Conn
@@ -34,10 +36,11 @@ type WGUDPProxy struct {
 }
 
 // NewWGUDPProxy instantiate a UDP based WireGuard proxy. This is not a thread safe implementation
-func NewWGUDPProxy(wgPort int) *WGUDPProxy {
+func NewWGUDPProxy(wgPort int, mtu uint16) *WGUDPProxy {
 	log.Debugf("Initializing new user space proxy with port %d", wgPort)
 	p := &WGUDPProxy{
 		localWGListenPort: wgPort,
+		mtu:               mtu,
 		closeListener:     listener.NewCloseListener(),
 	}
 	return p
@@ -144,7 +147,7 @@ func (p *WGUDPProxy) proxyToRemote(ctx context.Context) {
 		}
 	}()
 
-	buf := make([]byte, 1500)
+	buf := make([]byte, p.mtu+bufsize.WGBufferOverhead)
 	for ctx.Err() == nil {
 		n, err := p.localConn.Read(buf)
 		if err != nil {
@@ -179,7 +182,7 @@ func (p *WGUDPProxy) proxyToLocal(ctx context.Context) {
 		}
 	}()
 
-	buf := make([]byte, 1500)
+	buf := make([]byte, p.mtu+bufsize.WGBufferOverhead)
 	for {
 		n, err := p.remoteConnRead(ctx, buf)
 		if err != nil {

client/internal/auth/device_flow_test.go

@@ -3,15 +3,17 @@ package auth
 import (
 	"context"
 	"fmt"
-	"github.com/golang-jwt/jwt"
-	"github.com/netbirdio/netbird/client/internal"
-	"github.com/stretchr/testify/require"
 	"io"
 	"net/http"
 	"net/url"
 	"strings"
 	"testing"
 	"time"
+
+	"github.com/golang-jwt/jwt/v5"
+	"github.com/stretchr/testify/require"
+
+	"github.com/netbirdio/netbird/client/internal"
 )
 
 type mockHTTPClient struct {

client/internal/connect.go

@@ -18,6 +18,7 @@ import (
 	"google.golang.org/grpc/codes"
 	gstatus "google.golang.org/grpc/status"
 
+	"github.com/netbirdio/netbird/client/iface"
 	"github.com/netbirdio/netbird/client/iface/device"
 	"github.com/netbirdio/netbird/client/internal/dns"
 	"github.com/netbirdio/netbird/client/internal/listener"
@@ -33,7 +34,7 @@ import (
 	relayClient "github.com/netbirdio/netbird/shared/relay/client"
 	signal "github.com/netbirdio/netbird/shared/signal/client"
 	"github.com/netbirdio/netbird/util"
-	nbnet "github.com/netbirdio/netbird/util/net"
+	nbnet "github.com/netbirdio/netbird/client/net"
 	"github.com/netbirdio/netbird/version"
 )
 
@@ -244,7 +245,15 @@ func (c *ConnectClient) run(mobileDependency MobileDependency, runningChan chan
 		c.statusRecorder.MarkSignalConnected()
 
 		relayURLs, token := parseRelayInfo(loginResp)
-		relayManager := relayClient.NewManager(engineCtx, relayURLs, myPrivateKey.PublicKey().String())
+		peerConfig := loginResp.GetPeerConfig()
+
+		engineConfig, err := createEngineConfig(myPrivateKey, c.config, peerConfig)
+		if err != nil {
+			log.Error(err)
+			return wrapErr(err)
+		}
+
+		relayManager := relayClient.NewManager(engineCtx, relayURLs, myPrivateKey.PublicKey().String(), engineConfig.MTU)
 		c.statusRecorder.SetRelayMgr(relayManager)
 		if len(relayURLs) > 0 {
 			if token != nil {
@@ -259,14 +268,6 @@ func (c *ConnectClient) run(mobileDependency MobileDependency, runningChan chan
 			}
 		}
 
-		peerConfig := loginResp.GetPeerConfig()
-
-		engineConfig, err := createEngineConfig(myPrivateKey, c.config, peerConfig)
-		if err != nil {
-			log.Error(err)
-			return wrapErr(err)
-		}
-
 		checks := loginResp.GetChecks()
 
 		c.engineMutex.Lock()
@@ -274,7 +275,7 @@ func (c *ConnectClient) run(mobileDependency MobileDependency, runningChan chan
 		c.engine.SetSyncResponsePersistence(c.persistSyncResponse)
 		c.engineMutex.Unlock()
 
-		if err := c.engine.Start(); err != nil {
+		if err := c.engine.Start(loginResp.GetNetbirdConfig(), c.config.ManagementURL); err != nil {
 			log.Errorf("error while starting Netbird Connection Engine: %s", err)
 			return wrapErr(err)
 		}
@@ -283,10 +284,8 @@ func (c *ConnectClient) run(mobileDependency MobileDependency, runningChan chan
 		state.Set(StatusConnected)
 
 		if runningChan != nil {
-			select {
-			case runningChan <- struct{}{}:
-			default:
-			}
+			close(runningChan)
+			runningChan = nil
 		}
 
 		<-engineCtx.Done()
@@ -444,6 +443,8 @@ func createEngineConfig(key wgtypes.Key, config *profilemanager.Config, peerConf
 		BlockInbound:        config.BlockInbound,
 
 		LazyConnectionEnabled: config.LazyConnectionEnabled,
+
+		MTU: selectMTU(config.MTU, peerConfig.Mtu),
 	}
 
 	if config.PreSharedKey != "" {
@@ -466,6 +467,20 @@ func createEngineConfig(key wgtypes.Key, config *profilemanager.Config, peerConf
 	return engineConf, nil
 }
 
+func selectMTU(localMTU uint16, peerMTU int32) uint16 {
+	var finalMTU uint16 = iface.DefaultMTU
+	if localMTU > 0 {
+		finalMTU = localMTU
+	} else if peerMTU > 0 {
+		finalMTU = uint16(peerMTU)
+	}
+
+	// Set global DNS MTU
+	dns.SetCurrentMTU(finalMTU)
+
+	return finalMTU
+}
+
 // connectToSignal creates Signal Service client and established a connection
 func connectToSignal(ctx context.Context, wtConfig *mgmProto.NetbirdConfig, ourPrivateKey wgtypes.Key) (*signal.GrpcClient, error) {
 	var sigTLSEnabled bool

client/internal/dns/config/domains.go

@@ -0,0 +1,201 @@
+package config
+
+import (
+	"errors"
+	"fmt"
+	"net"
+	"net/netip"
+	"net/url"
+	"strings"
+
+	log "github.com/sirupsen/logrus"
+
+	"github.com/netbirdio/netbird/shared/management/domain"
+	mgmProto "github.com/netbirdio/netbird/shared/management/proto"
+)
+
+var (
+	ErrEmptyURL     = errors.New("empty URL")
+	ErrEmptyHost    = errors.New("empty host")
+	ErrIPNotAllowed = errors.New("IP address not allowed")
+)
+
+// ServerDomains represents the management server domains extracted from NetBird configuration
+type ServerDomains struct {
+	Signal domain.Domain
+	Relay  []domain.Domain
+	Flow   domain.Domain
+	Stuns  []domain.Domain
+	Turns  []domain.Domain
+}
+
+// ExtractFromNetbirdConfig extracts domain information from NetBird protobuf configuration
+func ExtractFromNetbirdConfig(config *mgmProto.NetbirdConfig) ServerDomains {
+	if config == nil {
+		return ServerDomains{}
+	}
+
+	domains := ServerDomains{}
+
+	domains.Signal = extractSignalDomain(config)
+	domains.Relay = extractRelayDomains(config)
+	domains.Flow = extractFlowDomain(config)
+	domains.Stuns = extractStunDomains(config)
+	domains.Turns = extractTurnDomains(config)
+
+	return domains
+}
+
+// ExtractValidDomain extracts a valid domain from a URL, filtering out IP addresses
+func ExtractValidDomain(rawURL string) (domain.Domain, error) {
+	if rawURL == "" {
+		return "", ErrEmptyURL
+	}
+
+	parsedURL, err := url.Parse(rawURL)
+	if err == nil {
+		if domain, err := extractFromParsedURL(parsedURL); err != nil || domain != "" {
+			return domain, err
+		}
+	}
+
+	return extractFromRawString(rawURL)
+}
+
+// extractFromParsedURL handles domain extraction from successfully parsed URLs
+func extractFromParsedURL(parsedURL *url.URL) (domain.Domain, error) {
+	if parsedURL.Hostname() != "" {
+		return extractDomainFromHost(parsedURL.Hostname())
+	}
+
+	if parsedURL.Opaque == "" || parsedURL.Scheme == "" {
+		return "", nil
+	}
+
+	// Handle URLs with opaque content (e.g., stun:host:port)
+	if strings.Contains(parsedURL.Scheme, ".") {
+		// This is likely "domain.com:port" being parsed as scheme:opaque
+		reconstructed := parsedURL.Scheme + ":" + parsedURL.Opaque
+		if host, _, err := net.SplitHostPort(reconstructed); err == nil {
+			return extractDomainFromHost(host)
+		}
+		return extractDomainFromHost(parsedURL.Scheme)
+	}
+
+	// Valid scheme with opaque content (e.g., stun:host:port)
+	host := parsedURL.Opaque
+	if queryIndex := strings.Index(host, "?"); queryIndex > 0 {
+		host = host[:queryIndex]
+	}
+
+	if hostOnly, _, err := net.SplitHostPort(host); err == nil {
+		return extractDomainFromHost(hostOnly)
+	}
+
+	return extractDomainFromHost(host)
+}
+
+// extractFromRawString handles domain extraction when URL parsing fails or returns no results
+func extractFromRawString(rawURL string) (domain.Domain, error) {
+	if host, _, err := net.SplitHostPort(rawURL); err == nil {
+		return extractDomainFromHost(host)
+	}
+
+	return extractDomainFromHost(rawURL)
+}
+
+// extractDomainFromHost extracts domain from a host string, filtering out IP addresses
+func extractDomainFromHost(host string) (domain.Domain, error) {
+	if host == "" {
+		return "", ErrEmptyHost
+	}
+
+	if _, err := netip.ParseAddr(host); err == nil {
+		return "", fmt.Errorf("%w: %s", ErrIPNotAllowed, host)
+	}
+
+	d, err := domain.FromString(host)
+	if err != nil {
+		return "", fmt.Errorf("invalid domain: %v", err)
+	}
+
+	return d, nil
+}
+
+// extractSingleDomain extracts a single domain from a URL with error logging
+func extractSingleDomain(url, serviceType string) domain.Domain {
+	if url == "" {
+		return ""
+	}
+
+	d, err := ExtractValidDomain(url)
+	if err != nil {
+		log.Debugf("Skipping %s: %v", serviceType, err)
+		return ""
+	}
+
+	return d
+}
+
+// extractMultipleDomains extracts multiple domains from URLs with error logging
+func extractMultipleDomains(urls []string, serviceType string) []domain.Domain {
+	var domains []domain.Domain
+	for _, url := range urls {
+		if url == "" {
+			continue
+		}
+		d, err := ExtractValidDomain(url)
+		if err != nil {
+			log.Debugf("Skipping %s: %v", serviceType, err)
+			continue
+		}
+		domains = append(domains, d)
+	}
+	return domains
+}
+
+// extractSignalDomain extracts the signal domain from NetBird configuration.
+func extractSignalDomain(config *mgmProto.NetbirdConfig) domain.Domain {
+	if config.Signal != nil {
+		return extractSingleDomain(config.Signal.Uri, "signal")
+	}
+	return ""
+}
+
+// extractRelayDomains extracts relay server domains from NetBird configuration.
+func extractRelayDomains(config *mgmProto.NetbirdConfig) []domain.Domain {
+	if config.Relay != nil {
+		return extractMultipleDomains(config.Relay.Urls, "relay")
+	}
+	return nil
+}
+
+// extractFlowDomain extracts the traffic flow domain from NetBird configuration.
+func extractFlowDomain(config *mgmProto.NetbirdConfig) domain.Domain {
+	if config.Flow != nil {
+		return extractSingleDomain(config.Flow.Url, "flow")
+	}
+	return ""
+}
+
+// extractStunDomains extracts STUN server domains from NetBird configuration.
+func extractStunDomains(config *mgmProto.NetbirdConfig) []domain.Domain {
+	var urls []string
+	for _, stun := range config.Stuns {
+		if stun != nil && stun.Uri != "" {
+			urls = append(urls, stun.Uri)
+		}
+	}
+	return extractMultipleDomains(urls, "STUN")
+}
+
+// extractTurnDomains extracts TURN server domains from NetBird configuration.
+func extractTurnDomains(config *mgmProto.NetbirdConfig) []domain.Domain {
+	var urls []string
+	for _, turn := range config.Turns {
+		if turn != nil && turn.HostConfig != nil && turn.HostConfig.Uri != "" {
+			urls = append(urls, turn.HostConfig.Uri)
+		}
+	}
+	return extractMultipleDomains(urls, "TURN")
+}

client/internal/dns/config/domains_test.go

@@ -0,0 +1,213 @@
+package config
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestExtractValidDomain(t *testing.T) {
+	tests := []struct {
+		name        string
+		url         string
+		expected    string
+		expectError bool
+	}{
+		{
+			name:     "HTTPS URL with port",
+			url:      "https://api.netbird.io:443",
+			expected: "api.netbird.io",
+		},
+		{
+			name:     "HTTP URL without port",
+			url:      "http://signal.example.com",
+			expected: "signal.example.com",
+		},
+		{
+			name:     "Host with port (no scheme)",
+			url:      "signal.netbird.io:443",
+			expected: "signal.netbird.io",
+		},
+		{
+			name:     "STUN URL",
+			url:      "stun:stun.netbird.io:443",
+			expected: "stun.netbird.io",
+		},
+		{
+			name:     "STUN URL with different port",
+			url:      "stun:stun.netbird.io:5555",
+			expected: "stun.netbird.io",
+		},
+		{
+			name:     "TURNS URL with query params",
+			url:      "turns:turn.netbird.io:443?transport=tcp",
+			expected: "turn.netbird.io",
+		},
+		{
+			name:     "TURN URL",
+			url:      "turn:turn.example.com:3478",
+			expected: "turn.example.com",
+		},
+		{
+			name:     "REL URL",
+			url:      "rel://relay.example.com:443",
+			expected: "relay.example.com",
+		},
+		{
+			name:     "RELS URL",
+			url:      "rels://relay.netbird.io:443",
+			expected: "relay.netbird.io",
+		},
+		{
+			name:     "Raw hostname",
+			url:      "example.org",
+			expected: "example.org",
+		},
+		{
+			name:        "IP address should be rejected",
+			url:         "192.168.1.1",
+			expectError: true,
+		},
+		{
+			name:        "IP address with port should be rejected",
+			url:         "192.168.1.1:443",
+			expectError: true,
+		},
+		{
+			name:        "IPv6 address should be rejected",
+			url:         "2001:db8::1",
+			expectError: true,
+		},
+		{
+			name:        "HTTP URL with IPv4 should be rejected",
+			url:         "http://192.168.1.1:8080",
+			expectError: true,
+		},
+		{
+			name:        "HTTPS URL with IPv4 should be rejected",
+			url:         "https://10.0.0.1:443",
+			expectError: true,
+		},
+		{
+			name:        "STUN URL with IPv4 should be rejected",
+			url:         "stun:192.168.1.1:3478",
+			expectError: true,
+		},
+		{
+			name:        "TURN URL with IPv4 should be rejected",
+			url:         "turn:10.0.0.1:3478",
+			expectError: true,
+		},
+		{
+			name:        "TURNS URL with IPv4 should be rejected",
+			url:         "turns:172.16.0.1:5349",
+			expectError: true,
+		},
+		{
+			name:        "HTTP URL with IPv6 should be rejected",
+			url:         "http://[2001:db8::1]:8080",
+			expectError: true,
+		},
+		{
+			name:        "HTTPS URL with IPv6 should be rejected",
+			url:         "https://[::1]:443",
+			expectError: true,
+		},
+		{
+			name:        "STUN URL with IPv6 should be rejected",
+			url:         "stun:[2001:db8::1]:3478",
+			expectError: true,
+		},
+		{
+			name:        "IPv6 with port should be rejected",
+			url:         "[2001:db8::1]:443",
+			expectError: true,
+		},
+		{
+			name:        "Localhost IPv4 should be rejected",
+			url:         "127.0.0.1:8080",
+			expectError: true,
+		},
+		{
+			name:        "Localhost IPv6 should be rejected",
+			url:         "[::1]:443",
+			expectError: true,
+		},
+		{
+			name:        "REL URL with IPv4 should be rejected",
+			url:         "rel://192.168.1.1:443",
+			expectError: true,
+		},
+		{
+			name:        "RELS URL with IPv4 should be rejected",
+			url:         "rels://10.0.0.1:443",
+			expectError: true,
+		},
+		{
+			name:        "Empty URL",
+			url:         "",
+			expectError: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result, err := ExtractValidDomain(tt.url)
+
+			if tt.expectError {
+				assert.Error(t, err, "Expected error for URL: %s", tt.url)
+			} else {
+				assert.NoError(t, err, "Unexpected error for URL: %s", tt.url)
+				assert.Equal(t, tt.expected, result.SafeString(), "Domain mismatch for URL: %s", tt.url)
+			}
+		})
+	}
+}
+
+func TestExtractDomainFromHost(t *testing.T) {
+	tests := []struct {
+		name        string
+		host        string
+		expected    string
+		expectError bool
+	}{
+		{
+			name:     "Valid domain",
+			host:     "example.com",
+			expected: "example.com",
+		},
+		{
+			name:     "Subdomain",
+			host:     "api.example.com",
+			expected: "api.example.com",
+		},
+		{
+			name:        "IPv4 address",
+			host:        "192.168.1.1",
+			expectError: true,
+		},
+		{
+			name:        "IPv6 address",
+			host:        "2001:db8::1",
+			expectError: true,
+		},
+		{
+			name:        "Empty host",
+			host:        "",
+			expectError: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result, err := extractDomainFromHost(tt.host)
+
+			if tt.expectError {
+				assert.Error(t, err, "Expected error for host: %s", tt.host)
+			} else {
+				assert.NoError(t, err, "Unexpected error for host: %s", tt.host)
+				assert.Equal(t, tt.expected, result.SafeString(), "Domain mismatch for host: %s", tt.host)
+			}
+		})
+	}
+}

client/internal/dns/handler_chain.go

@@ -11,11 +11,12 @@ import (
 )
 
 const (
-	PriorityLocal    = 100
-	PriorityDNSRoute = 75
-	PriorityUpstream = 50
-	PriorityDefault  = 1
-	PriorityFallback = -100
+	PriorityMgmtCache = 150
+	PriorityLocal     = 100
+	PriorityDNSRoute  = 75
+	PriorityUpstream  = 50
+	PriorityDefault   = 1
+	PriorityFallback  = -100
 )
 
 type SubdomainMatcher interface {
@@ -182,7 +183,10 @@ func (c *HandlerChain) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
 
 			// If handler wants to continue, try next handler
 			if chainWriter.shouldContinue {
-				log.Tracef("handler requested continue to next handler for domain=%s", qname)
+				// Only log continue for non-management cache handlers to reduce noise
+				if entry.Priority != PriorityMgmtCache {
+					log.Tracef("handler requested continue to next handler for domain=%s", qname)
+				}
 				continue
 			}
 			return

client/internal/dns/host_darwin.go

@@ -166,9 +166,10 @@ func (s *systemConfigurator) removeKeyFromSystemConfig(key string) error {
 
 func (s *systemConfigurator) addLocalDNS() error {
 	if !s.systemDNSSettings.ServerIP.IsValid() || len(s.systemDNSSettings.Domains) == 0 {
-		err := s.recordSystemDNSSettings(true)
-		log.Errorf("Unable to get system DNS configuration")
-		return err
+		if err := s.recordSystemDNSSettings(true); err != nil {
+			log.Errorf("Unable to get system DNS configuration")
+			return fmt.Errorf("recordSystemDNSSettings(): %w", err)
+		}
 	}
 	localKey := getKeyWithInput(netbirdDNSStateKeyFormat, localSuffix)
 	if s.systemDNSSettings.ServerIP.IsValid() && len(s.systemDNSSettings.Domains) != 0 {

client/internal/dns/local/local.go

@@ -34,7 +34,7 @@ func (d *Resolver) MatchSubdomains() bool {
 
 // String returns a string representation of the local resolver
 func (d *Resolver) String() string {
-	return fmt.Sprintf("local resolver [%d records]", len(d.records))
+	return fmt.Sprintf("LocalResolver [%d records]", len(d.records))
 }
 
 func (d *Resolver) Stop() {}

client/internal/dns/mgmt/mgmt.go

@@ -0,0 +1,360 @@
+package mgmt
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"net/url"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/miekg/dns"
+	log "github.com/sirupsen/logrus"
+
+	dnsconfig "github.com/netbirdio/netbird/client/internal/dns/config"
+	"github.com/netbirdio/netbird/shared/management/domain"
+)
+
+const dnsTimeout = 5 * time.Second
+
+// Resolver caches critical NetBird infrastructure domains
+type Resolver struct {
+	records       map[dns.Question][]dns.RR
+	mgmtDomain    *domain.Domain
+	serverDomains *dnsconfig.ServerDomains
+	mutex         sync.RWMutex
+}
+
+// NewResolver creates a new management domains cache resolver.
+func NewResolver() *Resolver {
+	return &Resolver{
+		records: make(map[dns.Question][]dns.RR),
+	}
+}
+
+// String returns a string representation of the resolver.
+func (m *Resolver) String() string {
+	return "MgmtCacheResolver"
+}
+
+// ServeDNS implements dns.Handler interface.
+func (m *Resolver) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
+	if len(r.Question) == 0 {
+		m.continueToNext(w, r)
+		return
+	}
+
+	question := r.Question[0]
+	question.Name = strings.ToLower(dns.Fqdn(question.Name))
+
+	if question.Qtype != dns.TypeA && question.Qtype != dns.TypeAAAA {
+		m.continueToNext(w, r)
+		return
+	}
+
+	m.mutex.RLock()
+	records, found := m.records[question]
+	m.mutex.RUnlock()
+
+	if !found {
+		m.continueToNext(w, r)
+		return
+	}
+
+	resp := &dns.Msg{}
+	resp.SetReply(r)
+	resp.Authoritative = false
+	resp.RecursionAvailable = true
+
+	resp.Answer = append(resp.Answer, records...)
+
+	log.Debugf("serving %d cached records for domain=%s", len(resp.Answer), question.Name)
+
+	if err := w.WriteMsg(resp); err != nil {
+		log.Errorf("failed to write response: %v", err)
+	}
+}
+
+// MatchSubdomains returns false since this resolver only handles exact domain matches
+// for NetBird infrastructure domains (signal, relay, flow, etc.), not their subdomains.
+func (m *Resolver) MatchSubdomains() bool {
+	return false
+}
+
+// continueToNext signals the handler chain to continue to the next handler.
+func (m *Resolver) continueToNext(w dns.ResponseWriter, r *dns.Msg) {
+	resp := &dns.Msg{}
+	resp.SetRcode(r, dns.RcodeNameError)
+	resp.MsgHdr.Zero = true
+	if err := w.WriteMsg(resp); err != nil {
+		log.Errorf("failed to write continue signal: %v", err)
+	}
+}
+
+// AddDomain manually adds a domain to cache by resolving it.
+func (m *Resolver) AddDomain(ctx context.Context, d domain.Domain) error {
+	dnsName := strings.ToLower(dns.Fqdn(d.PunycodeString()))
+
+	ctx, cancel := context.WithTimeout(ctx, dnsTimeout)
+	defer cancel()
+
+	ips, err := net.DefaultResolver.LookupNetIP(ctx, "ip", d.PunycodeString())
+	if err != nil {
+		return fmt.Errorf("resolve domain %s: %w", d.SafeString(), err)
+	}
+
+	var aRecords, aaaaRecords []dns.RR
+	for _, ip := range ips {
+		if ip.Is4() {
+			rr := &dns.A{
+				Hdr: dns.RR_Header{
+					Name:   dnsName,
+					Rrtype: dns.TypeA,
+					Class:  dns.ClassINET,
+					Ttl:    300,
+				},
+				A: ip.AsSlice(),
+			}
+			aRecords = append(aRecords, rr)
+		} else if ip.Is6() {
+			rr := &dns.AAAA{
+				Hdr: dns.RR_Header{
+					Name:   dnsName,
+					Rrtype: dns.TypeAAAA,
+					Class:  dns.ClassINET,
+					Ttl:    300,
+				},
+				AAAA: ip.AsSlice(),
+			}
+			aaaaRecords = append(aaaaRecords, rr)
+		}
+	}
+
+	m.mutex.Lock()
+
+	if len(aRecords) > 0 {
+		aQuestion := dns.Question{
+			Name:   dnsName,
+			Qtype:  dns.TypeA,
+			Qclass: dns.ClassINET,
+		}
+		m.records[aQuestion] = aRecords
+	}
+
+	if len(aaaaRecords) > 0 {
+		aaaaQuestion := dns.Question{
+			Name:   dnsName,
+			Qtype:  dns.TypeAAAA,
+			Qclass: dns.ClassINET,
+		}
+		m.records[aaaaQuestion] = aaaaRecords
+	}
+
+	m.mutex.Unlock()
+
+	log.Debugf("added domain=%s with %d A records and %d AAAA records",
+		d.SafeString(), len(aRecords), len(aaaaRecords))
+
+	return nil
+}
+
+// PopulateFromConfig extracts and caches domains from the client configuration.
+func (m *Resolver) PopulateFromConfig(ctx context.Context, mgmtURL *url.URL) error {
+	if mgmtURL == nil {
+		return nil
+	}
+
+	d, err := dnsconfig.ExtractValidDomain(mgmtURL.String())
+	if err != nil {
+		return fmt.Errorf("extract domain from URL: %w", err)
+	}
+
+	m.mutex.Lock()
+	m.mgmtDomain = &d
+	m.mutex.Unlock()
+
+	if err := m.AddDomain(ctx, d); err != nil {
+		return fmt.Errorf("add domain: %w", err)
+	}
+
+	return nil
+}
+
+// RemoveDomain removes a domain from the cache.
+func (m *Resolver) RemoveDomain(d domain.Domain) error {
+	dnsName := strings.ToLower(dns.Fqdn(d.PunycodeString()))
+
+	m.mutex.Lock()
+	defer m.mutex.Unlock()
+
+	aQuestion := dns.Question{
+		Name:   dnsName,
+		Qtype:  dns.TypeA,
+		Qclass: dns.ClassINET,
+	}
+	delete(m.records, aQuestion)
+
+	aaaaQuestion := dns.Question{
+		Name:   dnsName,
+		Qtype:  dns.TypeAAAA,
+		Qclass: dns.ClassINET,
+	}
+	delete(m.records, aaaaQuestion)
+
+	log.Debugf("removed domain=%s from cache", d.SafeString())
+	return nil
+}
+
+// GetCachedDomains returns a list of all cached domains.
+func (m *Resolver) GetCachedDomains() domain.List {
+	m.mutex.RLock()
+	defer m.mutex.RUnlock()
+
+	domainSet := make(map[domain.Domain]struct{})
+	for question := range m.records {
+		domainName := strings.TrimSuffix(question.Name, ".")
+		domainSet[domain.Domain(domainName)] = struct{}{}
+	}
+
+	domains := make(domain.List, 0, len(domainSet))
+	for d := range domainSet {
+		domains = append(domains, d)
+	}
+
+	return domains
+}
+
+// UpdateFromServerDomains updates the cache with server domains from network configuration.
+// It merges new domains with existing ones, replacing entire domain types when updated.
+// Empty updates are ignored to prevent clearing infrastructure domains during partial updates.
+func (m *Resolver) UpdateFromServerDomains(ctx context.Context, serverDomains dnsconfig.ServerDomains) (domain.List, error) {
+	newDomains := m.extractDomainsFromServerDomains(serverDomains)
+	var removedDomains domain.List
+
+	if len(newDomains) > 0 {
+		m.mutex.Lock()
+		if m.serverDomains == nil {
+			m.serverDomains = &dnsconfig.ServerDomains{}
+		}
+		updatedServerDomains := m.mergeServerDomains(*m.serverDomains, serverDomains)
+		m.serverDomains = &updatedServerDomains
+		m.mutex.Unlock()
+
+		allDomains := m.extractDomainsFromServerDomains(updatedServerDomains)
+		currentDomains := m.GetCachedDomains()
+		removedDomains = m.removeStaleDomains(currentDomains, allDomains)
+	}
+
+	m.addNewDomains(ctx, newDomains)
+
+	return removedDomains, nil
+}
+
+// removeStaleDomains removes cached domains not present in the target domain list.
+// Management domains are preserved and never removed during server domain updates.
+func (m *Resolver) removeStaleDomains(currentDomains, newDomains domain.List) domain.List {
+	var removedDomains domain.List
+
+	for _, currentDomain := range currentDomains {
+		if m.isDomainInList(currentDomain, newDomains) {
+			continue
+		}
+
+		if m.isManagementDomain(currentDomain) {
+			continue
+		}
+
+		removedDomains = append(removedDomains, currentDomain)
+		if err := m.RemoveDomain(currentDomain); err != nil {
+			log.Warnf("failed to remove domain=%s: %v", currentDomain.SafeString(), err)
+		}
+	}
+
+	return removedDomains
+}
+
+// mergeServerDomains merges new server domains with existing ones.
+// When a domain type is provided in the new domains, it completely replaces that type.
+func (m *Resolver) mergeServerDomains(existing, incoming dnsconfig.ServerDomains) dnsconfig.ServerDomains {
+	merged := existing
+
+	if incoming.Signal != "" {
+		merged.Signal = incoming.Signal
+	}
+	if len(incoming.Relay) > 0 {
+		merged.Relay = incoming.Relay
+	}
+	if incoming.Flow != "" {
+		merged.Flow = incoming.Flow
+	}
+	if len(incoming.Stuns) > 0 {
+		merged.Stuns = incoming.Stuns
+	}
+	if len(incoming.Turns) > 0 {
+		merged.Turns = incoming.Turns
+	}
+
+	return merged
+}
+
+// isDomainInList checks if domain exists in the list
+func (m *Resolver) isDomainInList(domain domain.Domain, list domain.List) bool {
+	for _, d := range list {
+		if domain.SafeString() == d.SafeString() {
+			return true
+		}
+	}
+	return false
+}
+
+// isManagementDomain checks if domain is the protected management domain
+func (m *Resolver) isManagementDomain(domain domain.Domain) bool {
+	m.mutex.RLock()
+	defer m.mutex.RUnlock()
+
+	return m.mgmtDomain != nil && domain == *m.mgmtDomain
+}
+
+// addNewDomains resolves and caches all domains from the update
+func (m *Resolver) addNewDomains(ctx context.Context, newDomains domain.List) {
+	for _, newDomain := range newDomains {
+		if err := m.AddDomain(ctx, newDomain); err != nil {
+			log.Warnf("failed to add/update domain=%s: %v", newDomain.SafeString(), err)
+		} else {
+			log.Debugf("added/updated management cache domain=%s", newDomain.SafeString())
+		}
+	}
+}
+
+func (m *Resolver) extractDomainsFromServerDomains(serverDomains dnsconfig.ServerDomains) domain.List {
+	var domains domain.List
+
+	if serverDomains.Signal != "" {
+		domains = append(domains, serverDomains.Signal)
+	}
+
+	for _, relay := range serverDomains.Relay {
+		if relay != "" {
+			domains = append(domains, relay)
+		}
+	}
+
+	if serverDomains.Flow != "" {
+		domains = append(domains, serverDomains.Flow)
+	}
+
+	for _, stun := range serverDomains.Stuns {
+		if stun != "" {
+			domains = append(domains, stun)
+		}
+	}
+
+	for _, turn := range serverDomains.Turns {
+		if turn != "" {
+			domains = append(domains, turn)
+		}
+	}
+
+	return domains
+}

client/internal/dns/mgmt/mgmt_test.go

@@ -0,0 +1,416 @@
+package mgmt
+
+import (
+	"context"
+	"fmt"
+	"net/url"
+	"strings"
+	"testing"
+
+	"github.com/miekg/dns"
+	"github.com/stretchr/testify/assert"
+
+	dnsconfig "github.com/netbirdio/netbird/client/internal/dns/config"
+	"github.com/netbirdio/netbird/client/internal/dns/test"
+	"github.com/netbirdio/netbird/shared/management/domain"
+)
+
+func TestResolver_NewResolver(t *testing.T) {
+	resolver := NewResolver()
+
+	assert.NotNil(t, resolver)
+	assert.NotNil(t, resolver.records)
+	assert.False(t, resolver.MatchSubdomains())
+}
+
+func TestResolver_ExtractDomainFromURL(t *testing.T) {
+	tests := []struct {
+		name        string
+		urlStr      string
+		expectedDom string
+		expectError bool
+	}{
+		{
+			name:        "HTTPS URL with port",
+			urlStr:      "https://api.netbird.io:443",
+			expectedDom: "api.netbird.io",
+			expectError: false,
+		},
+		{
+			name:        "HTTP URL without port",
+			urlStr:      "http://signal.example.com",
+			expectedDom: "signal.example.com",
+			expectError: false,
+		},
+		{
+			name:        "URL with path",
+			urlStr:      "https://relay.netbird.io/status",
+			expectedDom: "relay.netbird.io",
+			expectError: false,
+		},
+		{
+			name:        "Invalid URL",
+			urlStr:      "not-a-valid-url",
+			expectedDom: "not-a-valid-url",
+			expectError: false,
+		},
+		{
+			name:        "Empty URL",
+			urlStr:      "",
+			expectedDom: "",
+			expectError: true,
+		},
+		{
+			name:        "STUN URL",
+			urlStr:      "stun:stun.example.com:3478",
+			expectedDom: "stun.example.com",
+			expectError: false,
+		},
+		{
+			name:        "TURN URL",
+			urlStr:      "turn:turn.example.com:3478",
+			expectedDom: "turn.example.com",
+			expectError: false,
+		},
+		{
+			name:        "REL URL",
+			urlStr:      "rel://relay.example.com:443",
+			expectedDom: "relay.example.com",
+			expectError: false,
+		},
+		{
+			name:        "RELS URL",
+			urlStr:      "rels://relay.example.com:443",
+			expectedDom: "relay.example.com",
+			expectError: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var parsedURL *url.URL
+			var err error
+
+			if tt.urlStr != "" {
+				parsedURL, err = url.Parse(tt.urlStr)
+				if err != nil && !tt.expectError {
+					t.Fatalf("Failed to parse URL: %v", err)
+				}
+			}
+
+			domain, err := extractDomainFromURL(parsedURL)
+
+			if tt.expectError {
+				assert.Error(t, err)
+			} else {
+				assert.NoError(t, err)
+				assert.Equal(t, tt.expectedDom, domain.SafeString())
+			}
+		})
+	}
+}
+
+func TestResolver_PopulateFromConfig(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	resolver := NewResolver()
+
+	// Test with IP address - should return error since IP addresses are rejected
+	mgmtURL, _ := url.Parse("https://127.0.0.1")
+
+	err := resolver.PopulateFromConfig(ctx, mgmtURL)
+	assert.Error(t, err)
+	assert.ErrorIs(t, err, dnsconfig.ErrIPNotAllowed)
+
+	// No domains should be cached when using IP addresses
+	domains := resolver.GetCachedDomains()
+	assert.Equal(t, 0, len(domains), "No domains should be cached when using IP addresses")
+}
+
+func TestResolver_ServeDNS(t *testing.T) {
+	resolver := NewResolver()
+	ctx := context.Background()
+
+	// Add a test domain to the cache - use example.org which is reserved for testing
+	testDomain, err := domain.FromString("example.org")
+	if err != nil {
+		t.Fatalf("Failed to create domain: %v", err)
+	}
+	err = resolver.AddDomain(ctx, testDomain)
+	if err != nil {
+		t.Skipf("Skipping test due to DNS resolution failure: %v", err)
+	}
+
+	// Test A record query for cached domain
+	t.Run("Cached domain A record", func(t *testing.T) {
+		var capturedMsg *dns.Msg
+		mockWriter := &test.MockResponseWriter{
+			WriteMsgFunc: func(m *dns.Msg) error {
+				capturedMsg = m
+				return nil
+			},
+		}
+
+		req := new(dns.Msg)
+		req.SetQuestion("example.org.", dns.TypeA)
+
+		resolver.ServeDNS(mockWriter, req)
+
+		assert.NotNil(t, capturedMsg)
+		assert.Equal(t, dns.RcodeSuccess, capturedMsg.Rcode)
+		assert.True(t, len(capturedMsg.Answer) > 0, "Should have at least one answer")
+	})
+
+	// Test uncached domain signals to continue to next handler
+	t.Run("Uncached domain signals continue to next handler", func(t *testing.T) {
+		var capturedMsg *dns.Msg
+		mockWriter := &test.MockResponseWriter{
+			WriteMsgFunc: func(m *dns.Msg) error {
+				capturedMsg = m
+				return nil
+			},
+		}
+
+		req := new(dns.Msg)
+		req.SetQuestion("unknown.example.com.", dns.TypeA)
+
+		resolver.ServeDNS(mockWriter, req)
+
+		assert.NotNil(t, capturedMsg)
+		assert.Equal(t, dns.RcodeNameError, capturedMsg.Rcode)
+		// Zero flag set to true signals the handler chain to continue to next handler
+		assert.True(t, capturedMsg.MsgHdr.Zero, "Zero flag should be set to signal continuation to next handler")
+		assert.Empty(t, capturedMsg.Answer, "Should have no answers for uncached domain")
+	})
+
+	// Test that subdomains of cached domains are NOT resolved
+	t.Run("Subdomains of cached domains are not resolved", func(t *testing.T) {
+		var capturedMsg *dns.Msg
+		mockWriter := &test.MockResponseWriter{
+			WriteMsgFunc: func(m *dns.Msg) error {
+				capturedMsg = m
+				return nil
+			},
+		}
+
+		// Query for a subdomain of our cached domain
+		req := new(dns.Msg)
+		req.SetQuestion("sub.example.org.", dns.TypeA)
+
+		resolver.ServeDNS(mockWriter, req)
+
+		assert.NotNil(t, capturedMsg)
+		assert.Equal(t, dns.RcodeNameError, capturedMsg.Rcode)
+		assert.True(t, capturedMsg.MsgHdr.Zero, "Should signal continuation to next handler for subdomains")
+		assert.Empty(t, capturedMsg.Answer, "Should have no answers for subdomains")
+	})
+
+	// Test case-insensitive matching
+	t.Run("Case-insensitive domain matching", func(t *testing.T) {
+		var capturedMsg *dns.Msg
+		mockWriter := &test.MockResponseWriter{
+			WriteMsgFunc: func(m *dns.Msg) error {
+				capturedMsg = m
+				return nil
+			},
+		}
+
+		// Query with different casing
+		req := new(dns.Msg)
+		req.SetQuestion("EXAMPLE.ORG.", dns.TypeA)
+
+		resolver.ServeDNS(mockWriter, req)
+
+		assert.NotNil(t, capturedMsg)
+		assert.Equal(t, dns.RcodeSuccess, capturedMsg.Rcode)
+		assert.True(t, len(capturedMsg.Answer) > 0, "Should resolve regardless of case")
+	})
+}
+
+func TestResolver_GetCachedDomains(t *testing.T) {
+	resolver := NewResolver()
+	ctx := context.Background()
+
+	testDomain, err := domain.FromString("example.org")
+	if err != nil {
+		t.Fatalf("Failed to create domain: %v", err)
+	}
+	err = resolver.AddDomain(ctx, testDomain)
+	if err != nil {
+		t.Skipf("Skipping test due to DNS resolution failure: %v", err)
+	}
+
+	cachedDomains := resolver.GetCachedDomains()
+
+	assert.Equal(t, 1, len(cachedDomains), "Should return exactly one domain for single added domain")
+	assert.Equal(t, testDomain.SafeString(), cachedDomains[0].SafeString(), "Cached domain should match original")
+	assert.False(t, strings.HasSuffix(cachedDomains[0].PunycodeString(), "."), "Domain should not have trailing dot")
+}
+
+func TestResolver_ManagementDomainProtection(t *testing.T) {
+	resolver := NewResolver()
+	ctx := context.Background()
+
+	mgmtURL, _ := url.Parse("https://example.org")
+	err := resolver.PopulateFromConfig(ctx, mgmtURL)
+	if err != nil {
+		t.Skipf("Skipping test due to DNS resolution failure: %v", err)
+	}
+
+	initialDomains := resolver.GetCachedDomains()
+	if len(initialDomains) == 0 {
+		t.Skip("Management domain failed to resolve, skipping test")
+	}
+	assert.Equal(t, 1, len(initialDomains), "Should have management domain cached")
+	assert.Equal(t, "example.org", initialDomains[0].SafeString())
+
+	serverDomains := dnsconfig.ServerDomains{
+		Signal: "google.com",
+		Relay:  []domain.Domain{"cloudflare.com"},
+	}
+
+	_, err = resolver.UpdateFromServerDomains(ctx, serverDomains)
+	if err != nil {
+		t.Logf("Server domains update failed: %v", err)
+	}
+
+	finalDomains := resolver.GetCachedDomains()
+
+	managementStillCached := false
+	for _, d := range finalDomains {
+		if d.SafeString() == "example.org" {
+			managementStillCached = true
+			break
+		}
+	}
+	assert.True(t, managementStillCached, "Management domain should never be removed")
+}
+
+// extractDomainFromURL extracts a domain from a URL - test helper function
+func extractDomainFromURL(u *url.URL) (domain.Domain, error) {
+	if u == nil {
+		return "", fmt.Errorf("URL is nil")
+	}
+	return dnsconfig.ExtractValidDomain(u.String())
+}
+
+func TestResolver_EmptyUpdateDoesNotRemoveDomains(t *testing.T) {
+	resolver := NewResolver()
+	ctx := context.Background()
+
+	// Set up initial domains using resolvable domains
+	initialDomains := dnsconfig.ServerDomains{
+		Signal: "example.org",
+		Stuns:  []domain.Domain{"google.com"},
+		Turns:  []domain.Domain{"cloudflare.com"},
+	}
+
+	// Add initial domains
+	_, err := resolver.UpdateFromServerDomains(ctx, initialDomains)
+	if err != nil {
+		t.Skipf("Skipping test due to DNS resolution failure: %v", err)
+	}
+
+	// Verify domains were added
+	cachedDomains := resolver.GetCachedDomains()
+	assert.Len(t, cachedDomains, 3)
+
+	// Update with empty ServerDomains (simulating partial network map update)
+	emptyDomains := dnsconfig.ServerDomains{}
+	removedDomains, err := resolver.UpdateFromServerDomains(ctx, emptyDomains)
+	assert.NoError(t, err)
+
+	// Verify no domains were removed
+	assert.Len(t, removedDomains, 0, "No domains should be removed when update is empty")
+
+	// Verify all original domains are still cached
+	finalDomains := resolver.GetCachedDomains()
+	assert.Len(t, finalDomains, 3, "All original domains should still be cached")
+}
+
+func TestResolver_PartialUpdateReplacesOnlyUpdatedTypes(t *testing.T) {
+	resolver := NewResolver()
+	ctx := context.Background()
+
+	// Set up initial complete domains using resolvable domains
+	initialDomains := dnsconfig.ServerDomains{
+		Signal: "example.org",
+		Stuns:  []domain.Domain{"google.com"},
+		Turns:  []domain.Domain{"cloudflare.com"},
+	}
+
+	// Add initial domains
+	_, err := resolver.UpdateFromServerDomains(ctx, initialDomains)
+	if err != nil {
+		t.Skipf("Skipping test due to DNS resolution failure: %v", err)
+	}
+	assert.Len(t, resolver.GetCachedDomains(), 3)
+
+	// Update with partial ServerDomains (only signal domain - this should replace signal but preserve stun/turn)
+	partialDomains := dnsconfig.ServerDomains{
+		Signal: "github.com",
+	}
+	removedDomains, err := resolver.UpdateFromServerDomains(ctx, partialDomains)
+	if err != nil {
+		t.Skipf("Skipping test due to DNS resolution failure: %v", err)
+	}
+
+	// Should remove only the old signal domain
+	assert.Len(t, removedDomains, 1, "Should remove only the old signal domain")
+	assert.Equal(t, "example.org", removedDomains[0].SafeString())
+
+	finalDomains := resolver.GetCachedDomains()
+	assert.Len(t, finalDomains, 3, "Should have new signal plus preserved stun/turn domains")
+
+	domainStrings := make([]string, len(finalDomains))
+	for i, d := range finalDomains {
+		domainStrings[i] = d.SafeString()
+	}
+	assert.Contains(t, domainStrings, "github.com")
+	assert.Contains(t, domainStrings, "google.com")
+	assert.Contains(t, domainStrings, "cloudflare.com")
+	assert.NotContains(t, domainStrings, "example.org")
+}
+
+func TestResolver_PartialUpdateAddsNewTypePreservesExisting(t *testing.T) {
+	resolver := NewResolver()
+	ctx := context.Background()
+
+	// Set up initial complete domains using resolvable domains
+	initialDomains := dnsconfig.ServerDomains{
+		Signal: "example.org",
+		Stuns:  []domain.Domain{"google.com"},
+		Turns:  []domain.Domain{"cloudflare.com"},
+	}
+
+	// Add initial domains
+	_, err := resolver.UpdateFromServerDomains(ctx, initialDomains)
+	if err != nil {
+		t.Skipf("Skipping test due to DNS resolution failure: %v", err)
+	}
+	assert.Len(t, resolver.GetCachedDomains(), 3)
+
+	// Update with partial ServerDomains (only flow domain - new type, should preserve all existing)
+	partialDomains := dnsconfig.ServerDomains{
+		Flow: "github.com",
+	}
+	removedDomains, err := resolver.UpdateFromServerDomains(ctx, partialDomains)
+	if err != nil {
+		t.Skipf("Skipping test due to DNS resolution failure: %v", err)
+	}
+
+	assert.Len(t, removedDomains, 0, "Should not remove any domains when adding new type")
+
+	finalDomains := resolver.GetCachedDomains()
+	assert.Len(t, finalDomains, 4, "Should have all original domains plus new flow domain")
+
+	domainStrings := make([]string, len(finalDomains))
+	for i, d := range finalDomains {
+		domainStrings[i] = d.SafeString()
+	}
+	assert.Contains(t, domainStrings, "example.org")
+	assert.Contains(t, domainStrings, "google.com")
+	assert.Contains(t, domainStrings, "cloudflare.com")
+	assert.Contains(t, domainStrings, "github.com")
+}

client/internal/dns/mock_server.go

@@ -3,20 +3,23 @@ package dns
 import (
 	"fmt"
 	"net/netip"
+	"net/url"
 
 	"github.com/miekg/dns"
 
+	dnsconfig "github.com/netbirdio/netbird/client/internal/dns/config"
 	nbdns "github.com/netbirdio/netbird/dns"
 	"github.com/netbirdio/netbird/shared/management/domain"
 )
 
 // MockServer is the mock instance of a dns server
 type MockServer struct {
-	InitializeFunc        func() error
-	StopFunc              func()
-	UpdateDNSServerFunc   func(serial uint64, update nbdns.Config) error
-	RegisterHandlerFunc   func(domain.List, dns.Handler, int)
-	DeregisterHandlerFunc func(domain.List, int)
+	InitializeFunc         func() error
+	StopFunc               func()
+	UpdateDNSServerFunc    func(serial uint64, update nbdns.Config) error
+	RegisterHandlerFunc    func(domain.List, dns.Handler, int)
+	DeregisterHandlerFunc  func(domain.List, int)
+	UpdateServerConfigFunc func(domains dnsconfig.ServerDomains) error
 }
 
 func (m *MockServer) RegisterHandler(domains domain.List, handler dns.Handler, priority int) {
@@ -70,3 +73,14 @@ func (m *MockServer) SearchDomains() []string {
 // ProbeAvailability mocks implementation of ProbeAvailability from the Server interface
 func (m *MockServer) ProbeAvailability() {
 }
+
+func (m *MockServer) UpdateServerConfig(domains dnsconfig.ServerDomains) error {
+	if m.UpdateServerConfigFunc != nil {
+		return m.UpdateServerConfigFunc(domains)
+	}
+	return nil
+}
+
+func (m *MockServer) PopulateManagementDomain(mgmtURL *url.URL) error {
+	return nil
+}

client/internal/dns/server.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"net/netip"
+	"net/url"
 	"runtime"
 	"strings"
 	"sync"
@@ -15,7 +16,9 @@ import (
 	"golang.org/x/exp/maps"
 
 	"github.com/netbirdio/netbird/client/iface/netstack"
+	dnsconfig "github.com/netbirdio/netbird/client/internal/dns/config"
 	"github.com/netbirdio/netbird/client/internal/dns/local"
+	"github.com/netbirdio/netbird/client/internal/dns/mgmt"
 	"github.com/netbirdio/netbird/client/internal/dns/types"
 	"github.com/netbirdio/netbird/client/internal/listener"
 	"github.com/netbirdio/netbird/client/internal/peer"
@@ -45,6 +48,8 @@ type Server interface {
 	OnUpdatedHostDNSServer(addrs []netip.AddrPort)
 	SearchDomains() []string
 	ProbeAvailability()
+	UpdateServerConfig(domains dnsconfig.ServerDomains) error
+	PopulateManagementDomain(mgmtURL *url.URL) error
 }
 
 type nsGroupsByDomain struct {
@@ -77,6 +82,8 @@ type DefaultServer struct {
 	handlerChain       *HandlerChain
 	extraDomains       map[domain.Domain]int
 
+	mgmtCacheResolver *mgmt.Resolver
+
 	// permanent related properties
 	permanent      bool
 	hostsDNSHolder *hostsDNSHolder
@@ -104,18 +111,20 @@ type handlerWrapper struct {
 
 type registeredHandlerMap map[types.HandlerID]handlerWrapper
 
+// DefaultServerConfig holds configuration parameters for NewDefaultServer
+type DefaultServerConfig struct {
+	WgInterface    WGIface
+	CustomAddress  string
+	StatusRecorder *peer.Status
+	StateManager   *statemanager.Manager
+	DisableSys     bool
+}
+
 // NewDefaultServer returns a new dns server
-func NewDefaultServer(
-	ctx context.Context,
-	wgInterface WGIface,
-	customAddress string,
-	statusRecorder *peer.Status,
-	stateManager *statemanager.Manager,
-	disableSys bool,
-) (*DefaultServer, error) {
+func NewDefaultServer(ctx context.Context, config DefaultServerConfig) (*DefaultServer, error) {
 	var addrPort *netip.AddrPort
-	if customAddress != "" {
-		parsedAddrPort, err := netip.ParseAddrPort(customAddress)
+	if config.CustomAddress != "" {
+		parsedAddrPort, err := netip.ParseAddrPort(config.CustomAddress)
 		if err != nil {
 			return nil, fmt.Errorf("unable to parse the custom dns address, got error: %s", err)
 		}
@@ -123,13 +132,14 @@ func NewDefaultServer(
 	}
 
 	var dnsService service
-	if wgInterface.IsUserspaceBind() {
-		dnsService = NewServiceViaMemory(wgInterface)
+	if config.WgInterface.IsUserspaceBind() {
+		dnsService = NewServiceViaMemory(config.WgInterface)
 	} else {
-		dnsService = newServiceViaListener(wgInterface, addrPort)
+		dnsService = newServiceViaListener(config.WgInterface, addrPort)
 	}
 
-	return newDefaultServer(ctx, wgInterface, dnsService, statusRecorder, stateManager, disableSys), nil
+	server := newDefaultServer(ctx, config.WgInterface, dnsService, config.StatusRecorder, config.StateManager, config.DisableSys)
+	return server, nil
 }
 
 // NewDefaultServerPermanentUpstream returns a new dns server. It optimized for mobile systems
@@ -178,20 +188,24 @@ func newDefaultServer(
 ) *DefaultServer {
 	handlerChain := NewHandlerChain()
 	ctx, stop := context.WithCancel(ctx)
+
+	mgmtCacheResolver := mgmt.NewResolver()
+
 	defaultServer := &DefaultServer{
-		ctx:            ctx,
-		ctxCancel:      stop,
-		disableSys:     disableSys,
-		service:        dnsService,
-		handlerChain:   handlerChain,
-		extraDomains:   make(map[domain.Domain]int),
-		dnsMuxMap:      make(registeredHandlerMap),
-		localResolver:  local.NewResolver(),
-		wgInterface:    wgInterface,
-		statusRecorder: statusRecorder,
-		stateManager:   stateManager,
-		hostsDNSHolder: newHostsDNSHolder(),
-		hostManager:    &noopHostConfigurator{},
+		ctx:               ctx,
+		ctxCancel:         stop,
+		disableSys:        disableSys,
+		service:           dnsService,
+		handlerChain:      handlerChain,
+		extraDomains:      make(map[domain.Domain]int),
+		dnsMuxMap:         make(registeredHandlerMap),
+		localResolver:     local.NewResolver(),
+		wgInterface:       wgInterface,
+		statusRecorder:    statusRecorder,
+		stateManager:      stateManager,
+		hostsDNSHolder:    newHostsDNSHolder(),
+		hostManager:       &noopHostConfigurator{},
+		mgmtCacheResolver: mgmtCacheResolver,
 	}
 
 	// register with root zone, handler chain takes care of the routing
@@ -217,7 +231,7 @@ func (s *DefaultServer) RegisterHandler(domains domain.List, handler dns.Handler
 }
 
 func (s *DefaultServer) registerHandler(domains []string, handler dns.Handler, priority int) {
-	log.Debugf("registering handler %s with priority %d", handler, priority)
+	log.Debugf("registering handler %s with priority %d for %v", handler, priority, domains)
 
 	for _, domain := range domains {
 		if domain == "" {
@@ -246,7 +260,7 @@ func (s *DefaultServer) DeregisterHandler(domains domain.List, priority int) {
 }
 
 func (s *DefaultServer) deregisterHandler(domains []string, priority int) {
-	log.Debugf("deregistering handler %v with priority %d", domains, priority)
+	log.Debugf("deregistering handler with priority %d for %v", priority, domains)
 
 	for _, domain := range domains {
 		if domain == "" {
@@ -432,6 +446,29 @@ func (s *DefaultServer) ProbeAvailability() {
 	wg.Wait()
 }
 
+func (s *DefaultServer) UpdateServerConfig(domains dnsconfig.ServerDomains) error {
+	s.mux.Lock()
+	defer s.mux.Unlock()
+
+	if s.mgmtCacheResolver != nil {
+		removedDomains, err := s.mgmtCacheResolver.UpdateFromServerDomains(s.ctx, domains)
+		if err != nil {
+			return fmt.Errorf("update management cache resolver: %w", err)
+		}
+
+		if len(removedDomains) > 0 {
+			s.deregisterHandler(removedDomains.ToPunycodeList(), PriorityMgmtCache)
+		}
+
+		newDomains := s.mgmtCacheResolver.GetCachedDomains()
+		if len(newDomains) > 0 {
+			s.registerHandler(newDomains.ToPunycodeList(), s.mgmtCacheResolver, PriorityMgmtCache)
+		}
+	}
+
+	return nil
+}
+
 func (s *DefaultServer) applyConfiguration(update nbdns.Config) error {
 	// is the service should be Disabled, we stop the listener or fake resolver
 	if update.ServiceEnable {
@@ -961,3 +998,11 @@ func toZone(d domain.Domain) domain.Domain {
 		),
 	)
 }
+
+// PopulateManagementDomain populates the DNS cache with management domain
+func (s *DefaultServer) PopulateManagementDomain(mgmtURL *url.URL) error {
+	if s.mgmtCacheResolver != nil {
+		return s.mgmtCacheResolver.PopulateFromConfig(s.ctx, mgmtURL)
+	}
+	return nil
+}

client/internal/dns/server_test.go

@@ -363,7 +363,13 @@ func TestUpdateDNSServer(t *testing.T) {
 					t.Log(err)
 				}
 			}()
-			dnsServer, err := NewDefaultServer(context.Background(), wgIface, "", peer.NewRecorder("mgm"), nil, false)
+			dnsServer, err := NewDefaultServer(context.Background(), DefaultServerConfig{
+				WgInterface:    wgIface,
+				CustomAddress:  "",
+				StatusRecorder: peer.NewRecorder("mgm"),
+				StateManager:   nil,
+				DisableSys:     false,
+			})
 			if err != nil {
 				t.Fatal(err)
 			}
@@ -473,7 +479,13 @@ func TestDNSFakeResolverHandleUpdates(t *testing.T) {
 		return
 	}
 
-	dnsServer, err := NewDefaultServer(context.Background(), wgIface, "", peer.NewRecorder("mgm"), nil, false)
+	dnsServer, err := NewDefaultServer(context.Background(), DefaultServerConfig{
+		WgInterface:    wgIface,
+		CustomAddress:  "",
+		StatusRecorder: peer.NewRecorder("mgm"),
+		StateManager:   nil,
+		DisableSys:     false,
+	})
 	if err != nil {
 		t.Errorf("create DNS server: %v", err)
 		return
@@ -575,7 +587,13 @@ func TestDNSServerStartStop(t *testing.T) {
 
 	for _, testCase := range testCases {
 		t.Run(testCase.name, func(t *testing.T) {
-			dnsServer, err := NewDefaultServer(context.Background(), &mocWGIface{}, testCase.addrPort, peer.NewRecorder("mgm"), nil, false)
+			dnsServer, err := NewDefaultServer(context.Background(), DefaultServerConfig{
+				WgInterface:    &mocWGIface{},
+				CustomAddress:  testCase.addrPort,
+				StatusRecorder: peer.NewRecorder("mgm"),
+				StateManager:   nil,
+				DisableSys:     false,
+			})
 			if err != nil {
 				t.Fatalf("%v", err)
 			}

client/internal/dns/service_memory.go

@@ -10,7 +10,7 @@ import (
 	"github.com/miekg/dns"
 	log "github.com/sirupsen/logrus"
 
-	nbnet "github.com/netbirdio/netbird/util/net"
+	nbnet "github.com/netbirdio/netbird/client/net"
 )
 
 type ServiceViaMemory struct {

client/internal/dns/upstream.go

@@ -26,10 +26,18 @@ import (
 	"github.com/netbirdio/netbird/client/proto"
 )
 
-const (
-	UpstreamTimeout = 15 * time.Second
+var currentMTU uint16 = iface.DefaultMTU
+
+func SetCurrentMTU(mtu uint16) {
+	currentMTU = mtu
+}
+
+const (
+	UpstreamTimeout = 4 * time.Second
+	// ClientTimeout is the timeout for the dns.Client.
+	// Set longer than UpstreamTimeout to ensure context timeout takes precedence
+	ClientTimeout = 5 * time.Second
 
-	failsTillDeact   = int32(5)
 	reactivatePeriod = 30 * time.Second
 	probeTimeout     = 2 * time.Second
 )
@@ -52,9 +60,7 @@ type upstreamResolverBase struct {
 	upstreamServers  []netip.AddrPort
 	domain           string
 	disabled         bool
-	failsCount       atomic.Int32
 	successCount     atomic.Int32
-	failsTillDeact   int32
 	mutex            sync.Mutex
 	reactivatePeriod time.Duration
 	upstreamTimeout  time.Duration
@@ -73,14 +79,13 @@ func newUpstreamResolverBase(ctx context.Context, statusRecorder *peer.Status, d
 		domain:           domain,
 		upstreamTimeout:  UpstreamTimeout,
 		reactivatePeriod: reactivatePeriod,
-		failsTillDeact:   failsTillDeact,
 		statusRecorder:   statusRecorder,
 	}
 }
 
 // String returns a string representation of the upstream resolver
 func (u *upstreamResolverBase) String() string {
-	return fmt.Sprintf("upstream %s", u.upstreamServers)
+	return fmt.Sprintf("Upstream %s", u.upstreamServers)
 }
 
 // ID returns the unique handler ID
@@ -110,58 +115,102 @@ func (u *upstreamResolverBase) Stop() {
 func (u *upstreamResolverBase) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
 	requestID := GenerateRequestID()
 	logger := log.WithField("request_id", requestID)
-	var err error
-	defer func() {
-		u.checkUpstreamFails(err)
-	}()
 
 	logger.Tracef("received upstream question: domain=%s type=%v class=%v", r.Question[0].Name, r.Question[0].Qtype, r.Question[0].Qclass)
+
+	u.prepareRequest(r)
+
+	if u.ctx.Err() != nil {
+		logger.Tracef("%s has been stopped", u)
+		return
+	}
+
+	if u.tryUpstreamServers(w, r, logger) {
+		return
+	}
+
+	u.writeErrorResponse(w, r, logger)
+}
+
+func (u *upstreamResolverBase) prepareRequest(r *dns.Msg) {
 	if r.Extra == nil {
 		r.MsgHdr.AuthenticatedData = true
 	}
+}
 
-	select {
-	case <-u.ctx.Done():
-		logger.Tracef("%s has been stopped", u)
-		return
-	default:
+func (u *upstreamResolverBase) tryUpstreamServers(w dns.ResponseWriter, r *dns.Msg, logger *log.Entry) bool {
+	timeout := u.upstreamTimeout
+	if len(u.upstreamServers) > 1 {
+		maxTotal := 5 * time.Second
+		minPerUpstream := 2 * time.Second
+		scaledTimeout := maxTotal / time.Duration(len(u.upstreamServers))
+		if scaledTimeout > minPerUpstream {
+			timeout = scaledTimeout
+		} else {
+			timeout = minPerUpstream
+		}
 	}
 
 	for _, upstream := range u.upstreamServers {
-		var rm *dns.Msg
-		var t time.Duration
-
-		func() {
-			ctx, cancel := context.WithTimeout(u.ctx, u.upstreamTimeout)
-			defer cancel()
-			rm, t, err = u.upstreamClient.exchange(ctx, upstream.String(), r)
-		}()
-
-		if err != nil {
-			if errors.Is(err, context.DeadlineExceeded) || isTimeout(err) {
-				logger.Warnf("upstream %s timed out for question domain=%s", upstream, r.Question[0].Name)
-				continue
-			}
-			logger.Warnf("failed to query upstream %s for question domain=%s: %s", upstream, r.Question[0].Name, err)
-			continue
+		if u.queryUpstream(w, r, upstream, timeout, logger) {
+			return true
 		}
+	}
+	return false
+}
 
-		if rm == nil || !rm.Response {
-			logger.Warnf("no response from upstream %s for question domain=%s", upstream, r.Question[0].Name)
-			continue
-		}
+func (u *upstreamResolverBase) queryUpstream(w dns.ResponseWriter, r *dns.Msg, upstream netip.AddrPort, timeout time.Duration, logger *log.Entry) bool {
+	var rm *dns.Msg
+	var t time.Duration
+	var err error
 
-		u.successCount.Add(1)
-		logger.Tracef("took %s to query the upstream %s for question domain=%s", t, upstream, r.Question[0].Name)
+	var startTime time.Time
+	func() {
+		ctx, cancel := context.WithTimeout(u.ctx, timeout)
+		defer cancel()
+		startTime = time.Now()
+		rm, t, err = u.upstreamClient.exchange(ctx, upstream.String(), r)
+	}()
 
-		if err = w.WriteMsg(rm); err != nil {
-			logger.Errorf("failed to write DNS response for question domain=%s: %s", r.Question[0].Name, err)
-		}
-		// count the fails only if they happen sequentially
-		u.failsCount.Store(0)
+	if err != nil {
+		u.handleUpstreamError(err, upstream, r.Question[0].Name, startTime, timeout, logger)
+		return false
+	}
+
+	if rm == nil || !rm.Response {
+		logger.Warnf("no response from upstream %s for question domain=%s", upstream, r.Question[0].Name)
+		return false
+	}
+
+	return u.writeSuccessResponse(w, rm, upstream, r.Question[0].Name, t, logger)
+}
+
+func (u *upstreamResolverBase) handleUpstreamError(err error, upstream netip.AddrPort, domain string, startTime time.Time, timeout time.Duration, logger *log.Entry) {
+	if !errors.Is(err, context.DeadlineExceeded) && !isTimeout(err) {
+		logger.Warnf("failed to query upstream %s for question domain=%s: %s", upstream, domain, err)
 		return
 	}
-	u.failsCount.Add(1)
+
+	elapsed := time.Since(startTime)
+	timeoutMsg := fmt.Sprintf("upstream %s timed out for question domain=%s after %v (timeout=%v)", upstream, domain, elapsed.Truncate(time.Millisecond), timeout)
+	if peerInfo := u.debugUpstreamTimeout(upstream); peerInfo != "" {
+		timeoutMsg += " " + peerInfo
+	}
+	timeoutMsg += fmt.Sprintf(" - error: %v", err)
+	logger.Warnf(timeoutMsg)
+}
+
+func (u *upstreamResolverBase) writeSuccessResponse(w dns.ResponseWriter, rm *dns.Msg, upstream netip.AddrPort, domain string, t time.Duration, logger *log.Entry) bool {
+	u.successCount.Add(1)
+	logger.Tracef("took %s to query the upstream %s for question domain=%s", t, upstream, domain)
+
+	if err := w.WriteMsg(rm); err != nil {
+		logger.Errorf("failed to write DNS response for question domain=%s: %s", domain, err)
+	}
+	return true
+}
+
+func (u *upstreamResolverBase) writeErrorResponse(w dns.ResponseWriter, r *dns.Msg, logger *log.Entry) {
 	logger.Errorf("all queries to the %s failed for question domain=%s", u, r.Question[0].Name)
 
 	m := new(dns.Msg)
@@ -171,41 +220,6 @@ func (u *upstreamResolverBase) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
 	}
 }
 
-// checkUpstreamFails counts fails and disables or enables upstream resolving
-//
-// If fails count is greater that failsTillDeact, upstream resolving
-// will be disabled for reactivatePeriod, after that time period fails counter
-// will be reset and upstream will be reactivated.
-func (u *upstreamResolverBase) checkUpstreamFails(err error) {
-	u.mutex.Lock()
-	defer u.mutex.Unlock()
-
-	if u.failsCount.Load() < u.failsTillDeact || u.disabled {
-		return
-	}
-
-	select {
-	case <-u.ctx.Done():
-		return
-	default:
-	}
-
-	u.disable(err)
-
-	if u.statusRecorder == nil {
-		return
-	}
-
-	u.statusRecorder.PublishEvent(
-		proto.SystemEvent_WARNING,
-		proto.SystemEvent_DNS,
-		"All upstream servers failed (fail count exceeded)",
-		"Unable to reach one or more DNS servers. This might affect your ability to connect to some services.",
-		map[string]string{"upstreams": u.upstreamServersString()},
-		// TODO add domain meta
-	)
-}
-
 // ProbeAvailability tests all upstream servers simultaneously and
 // disables the resolver if none work
 func (u *upstreamResolverBase) ProbeAvailability() {
@@ -218,8 +232,8 @@ func (u *upstreamResolverBase) ProbeAvailability() {
 	default:
 	}
 
-	// avoid probe if upstreams could resolve at least one query and fails count is less than failsTillDeact
-	if u.successCount.Load() > 0 && u.failsCount.Load() < u.failsTillDeact {
+	// avoid probe if upstreams could resolve at least one query
+	if u.successCount.Load() > 0 {
 		return
 	}
 
@@ -306,7 +320,6 @@ func (u *upstreamResolverBase) waitUntilResponse() {
 	}
 
 	log.Infof("upstreams %s are responsive again. Adding them back to system", u.upstreamServersString())
-	u.failsCount.Store(0)
 	u.successCount.Add(1)
 	u.reactivate()
 	u.disabled = false
@@ -358,8 +371,8 @@ func (u *upstreamResolverBase) testNameserver(server netip.AddrPort, timeout tim
 // If the passed context is nil, this will use Exchange instead of ExchangeContext.
 func ExchangeWithFallback(ctx context.Context, client *dns.Client, r *dns.Msg, upstream string) (*dns.Msg, time.Duration, error) {
 	// MTU - ip + udp headers
-	// Note: this could be sent out on an interface that is not ours, but our MTU should always be lower.
-	client.UDPSize = iface.DefaultMTU - (60 + 8)
+	// Note: this could be sent out on an interface that is not ours, but higher MTU settings could break truncation handling.
+	client.UDPSize = uint16(currentMTU - (60 + 8))
 
 	var (
 		rm  *dns.Msg
@@ -410,3 +423,80 @@ func GenerateRequestID() string {
 	}
 	return hex.EncodeToString(bytes)
 }
+
+// FormatPeerStatus formats peer connection status information for debugging DNS timeouts
+func FormatPeerStatus(peerState *peer.State) string {
+	isConnected := peerState.ConnStatus == peer.StatusConnected
+	hasRecentHandshake := !peerState.LastWireguardHandshake.IsZero() &&
+		time.Since(peerState.LastWireguardHandshake) < 3*time.Minute
+
+	statusInfo := fmt.Sprintf("%s:%s", peerState.FQDN, peerState.IP)
+
+	switch {
+	case !isConnected:
+		statusInfo += " DISCONNECTED"
+	case !hasRecentHandshake:
+		statusInfo += " NO_RECENT_HANDSHAKE"
+	default:
+		statusInfo += " connected"
+	}
+
+	if !peerState.LastWireguardHandshake.IsZero() {
+		timeSinceHandshake := time.Since(peerState.LastWireguardHandshake)
+		statusInfo += fmt.Sprintf(" last_handshake=%v_ago", timeSinceHandshake.Truncate(time.Second))
+	} else {
+		statusInfo += " no_handshake"
+	}
+
+	if peerState.Relayed {
+		statusInfo += " via_relay"
+	}
+
+	if peerState.Latency > 0 {
+		statusInfo += fmt.Sprintf(" latency=%v", peerState.Latency)
+	}
+
+	return statusInfo
+}
+
+// findPeerForIP finds which peer handles the given IP address
+func findPeerForIP(ip netip.Addr, statusRecorder *peer.Status) *peer.State {
+	if statusRecorder == nil {
+		return nil
+	}
+
+	fullStatus := statusRecorder.GetFullStatus()
+	var bestMatch *peer.State
+	var bestPrefixLen int
+
+	for _, peerState := range fullStatus.Peers {
+		routes := peerState.GetRoutes()
+		for route := range routes {
+			prefix, err := netip.ParsePrefix(route)
+			if err != nil {
+				continue
+			}
+
+			if prefix.Contains(ip) && prefix.Bits() > bestPrefixLen {
+				peerStateCopy := peerState
+				bestMatch = &peerStateCopy
+				bestPrefixLen = prefix.Bits()
+			}
+		}
+	}
+
+	return bestMatch
+}
+
+func (u *upstreamResolverBase) debugUpstreamTimeout(upstream netip.AddrPort) string {
+	if u.statusRecorder == nil {
+		return ""
+	}
+
+	peerInfo := findPeerForIP(upstream.Addr(), u.statusRecorder)
+	if peerInfo == nil {
+		return ""
+	}
+
+	return fmt.Sprintf("(routes through NetBird peer %s)", FormatPeerStatus(peerInfo))
+}

client/internal/dns/upstream_android.go

@@ -10,7 +10,7 @@ import (
 	"github.com/miekg/dns"
 
 	"github.com/netbirdio/netbird/client/internal/peer"
-	nbnet "github.com/netbirdio/netbird/util/net"
+	nbnet "github.com/netbirdio/netbird/client/net"
 )
 
 type upstreamResolver struct {
@@ -50,7 +50,9 @@ func (u *upstreamResolver) exchange(ctx context.Context, upstream string, r *dns
 }
 
 func (u *upstreamResolver) exchangeWithinVPN(ctx context.Context, upstream string, r *dns.Msg) (rm *dns.Msg, t time.Duration, err error) {
-	upstreamExchangeClient := &dns.Client{}
+	upstreamExchangeClient := &dns.Client{
+		Timeout: ClientTimeout,
+	}
 	return upstreamExchangeClient.ExchangeContext(ctx, r, upstream)
 }
 
@@ -72,10 +74,11 @@ func (u *upstreamResolver) exchangeWithoutVPN(ctx context.Context, upstream stri
 	}
 
 	upstreamExchangeClient := &dns.Client{
-		Dialer: dialer,
+		Dialer:  dialer,
+		Timeout: timeout,
 	}
 
-	return upstreamExchangeClient.Exchange(r, upstream)
+	return upstreamExchangeClient.ExchangeContext(ctx, r, upstream)
 }
 
 func (u *upstreamResolver) isLocalResolver(upstream string) bool {

client/internal/dns/upstream_general.go

@@ -34,7 +34,10 @@ func newUpstreamResolver(
 }
 
 func (u *upstreamResolver) exchange(ctx context.Context, upstream string, r *dns.Msg) (rm *dns.Msg, t time.Duration, err error) {
-	return ExchangeWithFallback(ctx, &dns.Client{}, r, upstream)
+	client := &dns.Client{
+		Timeout: ClientTimeout,
+	}
+	return ExchangeWithFallback(ctx, client, r, upstream)
 }
 
 func GetClientPrivate(ip netip.Addr, interfaceName string, dialTimeout time.Duration) (*dns.Client, error) {

client/internal/dns/upstream_ios.go

@@ -47,7 +47,9 @@ func newUpstreamResolver(
 }
 
 func (u *upstreamResolverIOS) exchange(ctx context.Context, upstream string, r *dns.Msg) (rm *dns.Msg, t time.Duration, err error) {
-	client := &dns.Client{}
+	client := &dns.Client{
+		Timeout: ClientTimeout,
+	}
 	upstreamHost, _, err := net.SplitHostPort(upstream)
 	if err != nil {
 		return nil, 0, fmt.Errorf("error while parsing upstream host: %s", err)
@@ -110,7 +112,8 @@ func GetClientPrivate(ip netip.Addr, interfaceName string, dialTimeout time.Dura
 		},
 	}
 	client := &dns.Client{
-		Dialer: dialer,
+		Dialer:  dialer,
+		Timeout: dialTimeout,
 	}
 	return client, nil
 }

client/internal/dns/upstream_test.go

@@ -124,29 +124,26 @@ func (c mockUpstreamResolver) exchange(_ context.Context, _ string, _ *dns.Msg)
 }
 
 func TestUpstreamResolver_DeactivationReactivation(t *testing.T) {
+	mockClient := &mockUpstreamResolver{
+		err: dns.ErrTime,
+		r:   new(dns.Msg),
+		rtt: time.Millisecond,
+	}
+
 	resolver := &upstreamResolverBase{
-		ctx: context.TODO(),
-		upstreamClient: &mockUpstreamResolver{
-			err: nil,
-			r:   new(dns.Msg),
-			rtt: time.Millisecond,
-		},
+		ctx:              context.TODO(),
+		upstreamClient:   mockClient,
 		upstreamTimeout:  UpstreamTimeout,
-		reactivatePeriod: reactivatePeriod,
-		failsTillDeact:   failsTillDeact,
+		reactivatePeriod: time.Microsecond * 100,
 	}
 	addrPort, _ := netip.ParseAddrPort("0.0.0.0:1") // Use valid port for parsing, test will still fail on connection
 	resolver.upstreamServers = []netip.AddrPort{netip.AddrPortFrom(addrPort.Addr().Unmap(), addrPort.Port())}
-	resolver.failsTillDeact = 0
-	resolver.reactivatePeriod = time.Microsecond * 100
-
-	responseWriter := &test.MockResponseWriter{
-		WriteMsgFunc: func(m *dns.Msg) error { return nil },
-	}
 
 	failed := false
 	resolver.deactivate = func(error) {
 		failed = true
+		// After deactivation, make the mock client work again
+		mockClient.err = nil
 	}
 
 	reactivated := false
@@ -154,7 +151,7 @@ func TestUpstreamResolver_DeactivationReactivation(t *testing.T) {
 		reactivated = true
 	}
 
-	resolver.ServeDNS(responseWriter, new(dns.Msg).SetQuestion("one.one.one.one.", dns.TypeA))
+	resolver.ProbeAvailability()
 
 	if !failed {
 		t.Errorf("expected that resolving was deactivated")
@@ -173,11 +170,6 @@ func TestUpstreamResolver_DeactivationReactivation(t *testing.T) {
 		return
 	}
 
-	if resolver.failsCount.Load() != 0 {
-		t.Errorf("fails count after reactivation should be 0")
-		return
-	}
-
 	if resolver.disabled {
 		t.Errorf("should be enabled")
 	}

client/internal/engine.go

@@ -7,6 +7,7 @@ import (
 	"math/rand"
 	"net"
 	"net/netip"
+	"net/url"
 	"os"
 	"reflect"
 	"runtime"
@@ -17,8 +18,8 @@ import (
 	"time"
 
 	"github.com/hashicorp/go-multierror"
-	"github.com/pion/ice/v3"
-	"github.com/pion/stun/v2"
+	"github.com/pion/ice/v4"
+	"github.com/pion/stun/v3"
 	log "github.com/sirupsen/logrus"
 	"golang.zx2c4.com/wireguard/tun/netstack"
 	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
@@ -28,11 +29,12 @@ import (
 	"github.com/netbirdio/netbird/client/firewall"
 	firewallManager "github.com/netbirdio/netbird/client/firewall/manager"
 	"github.com/netbirdio/netbird/client/iface"
-	"github.com/netbirdio/netbird/client/iface/bind"
 	"github.com/netbirdio/netbird/client/iface/device"
 	nbnetstack "github.com/netbirdio/netbird/client/iface/netstack"
+	"github.com/netbirdio/netbird/client/iface/udpmux"
 	"github.com/netbirdio/netbird/client/internal/acl"
 	"github.com/netbirdio/netbird/client/internal/dns"
+	dnsconfig "github.com/netbirdio/netbird/client/internal/dns/config"
 	"github.com/netbirdio/netbird/client/internal/dnsfwd"
 	"github.com/netbirdio/netbird/client/internal/ingressgw"
 	"github.com/netbirdio/netbird/client/internal/netflow"
@@ -125,6 +127,8 @@ type EngineConfig struct {
 	BlockInbound        bool
 
 	LazyConnectionEnabled bool
+
+	MTU uint16
 }
 
 // Engine is a mechanism responsible for reacting on Signal and Management stream events and managing connections to the remote peers.
@@ -162,7 +166,7 @@ type Engine struct {
 
 	wgInterface WGIface
 
-	udpMux *bind.UniversalUDPMuxDefault
+	udpMux *udpmux.UniversalUDPMuxDefault
 
 	// networkSerial is the latest CurrentSerial (state ID) of the network sent by the Management service
 	networkSerial uint64
@@ -194,6 +198,10 @@ type Engine struct {
 	latestSyncResponse  *mgmProto.SyncResponse
 	connSemaphore       *semaphoregroup.SemaphoreGroup
 	flowManager         nftypes.FlowManager
+
+	// WireGuard interface monitor
+	wgIfaceMonitor   *WGIfaceMonitor
+	wgIfaceMonitorWg sync.WaitGroup
 }
 
 // Peer is an instance of the Connection Peer
@@ -337,16 +345,23 @@ func (e *Engine) Stop() error {
 		log.Errorf("failed to persist state: %v", err)
 	}
 
+	// Stop WireGuard interface monitor and wait for it to exit
+	e.wgIfaceMonitorWg.Wait()
+
 	return nil
 }
 
 // Start creates a new WireGuard tunnel interface and listens to events from Signal and Management services
 // Connections to remote peers are not established here.
 // However, they will be established once an event with a list of peers to connect to will be received from Management Service
-func (e *Engine) Start() error {
+func (e *Engine) Start(netbirdConfig *mgmProto.NetbirdConfig, mgmtURL *url.URL) error {
 	e.syncMsgMux.Lock()
 	defer e.syncMsgMux.Unlock()
 
+	if err := iface.ValidateMTU(e.config.MTU); err != nil {
+		return fmt.Errorf("invalid MTU configuration: %w", err)
+	}
+
 	if e.cancel != nil {
 		e.cancel()
 	}
@@ -395,6 +410,11 @@ func (e *Engine) Start() error {
 	}
 	e.dnsServer = dnsServer
 
+	// Populate DNS cache with NetbirdConfig and management URL for early resolution
+	if err := e.PopulateNetbirdConfig(netbirdConfig, mgmtURL); err != nil {
+		log.Warnf("failed to populate DNS cache: %v", err)
+	}
+
 	e.routeManager = routemanager.NewManager(routemanager.ManagerConfig{
 		Context:             e.ctx,
 		PublicKey:           e.config.WgPrivateKey.PublicKey().String(),
@@ -433,6 +453,8 @@ func (e *Engine) Start() error {
 		return fmt.Errorf("up wg interface: %w", err)
 	}
 
+
+
 	// if inbound conns are blocked there is no need to create the ACL manager
 	if e.firewall != nil && !e.config.BlockInbound {
 		e.acl = acl.NewDefaultManager(e.firewall)
@@ -448,7 +470,7 @@ func (e *Engine) Start() error {
 		StunTurn:             &e.stunTurn,
 		InterfaceBlackList:   e.config.IFaceBlackList,
 		DisableIPv6Discovery: e.config.DisableIPv6Discovery,
-		UDPMux:               e.udpMux.UDPMuxDefault,
+		UDPMux:               e.udpMux.SingleSocketUDPMux,
 		UDPMuxSrflx:          e.udpMux,
 		NATExternalIPs:       e.parseNATExternalIPMappings(),
 	}
@@ -464,6 +486,22 @@ func (e *Engine) Start() error {
 
 	// starting network monitor at the very last to avoid disruptions
 	e.startNetworkMonitor()
+
+	// monitor WireGuard interface lifecycle and restart engine on changes
+	e.wgIfaceMonitor = NewWGIfaceMonitor()
+	e.wgIfaceMonitorWg.Add(1)
+
+	go func() {
+		defer e.wgIfaceMonitorWg.Done()
+
+		if shouldRestart, err := e.wgIfaceMonitor.Start(e.ctx, e.wgInterface.Name()); shouldRestart {
+			log.Infof("WireGuard interface monitor: %s, restarting engine", err)
+			e.restartEngine()
+		} else if err != nil {
+			log.Warnf("WireGuard interface monitor: %s", err)
+		}
+	}()
+
 	return nil
 }
 
@@ -655,6 +693,30 @@ func (e *Engine) removePeer(peerKey string) error {
 	return nil
 }
 
+// PopulateNetbirdConfig populates the DNS cache with infrastructure domains from login response
+func (e *Engine) PopulateNetbirdConfig(netbirdConfig *mgmProto.NetbirdConfig, mgmtURL *url.URL) error {
+	if e.dnsServer == nil {
+		return nil
+	}
+
+	// Populate management URL if provided
+	if mgmtURL != nil {
+		if err := e.dnsServer.PopulateManagementDomain(mgmtURL); err != nil {
+			log.Warnf("failed to populate DNS cache with management URL: %v", err)
+		}
+	}
+
+	// Populate NetbirdConfig domains if provided
+	if netbirdConfig != nil {
+		serverDomains := dnsconfig.ExtractFromNetbirdConfig(netbirdConfig)
+		if err := e.dnsServer.UpdateServerConfig(serverDomains); err != nil {
+			return fmt.Errorf("update DNS server config from NetbirdConfig: %w", err)
+		}
+	}
+
+	return nil
+}
+
 func (e *Engine) handleSync(update *mgmProto.SyncResponse) error {
 	e.syncMsgMux.Lock()
 	defer e.syncMsgMux.Unlock()
@@ -686,6 +748,10 @@ func (e *Engine) handleSync(update *mgmProto.SyncResponse) error {
 			return fmt.Errorf("handle the flow configuration: %w", err)
 		}
 
+		if err := e.PopulateNetbirdConfig(wCfg, nil); err != nil {
+			log.Warnf("Failed to update DNS server config: %v", err)
+		}
+
 		// todo update signal
 	}
 
@@ -908,7 +974,6 @@ func (e *Engine) receiveManagementEvents() {
 			e.config.LazyConnectionEnabled,
 		)
 
-		// err = e.mgmClient.Sync(info, e.handleSync)
 		err = e.mgmClient.Sync(e.ctx, info, e.handleSync)
 		if err != nil {
 			// happens if management is unavailable for a long time.
@@ -919,7 +984,7 @@ func (e *Engine) receiveManagementEvents() {
 		}
 		log.Debugf("stopped receiving updates from Management Service")
 	}()
-	log.Debugf("connecting to Management Service updates stream")
+	log.Infof("connecting to Management Service updates stream")
 }
 
 func (e *Engine) updateSTUNs(stuns []*mgmProto.HostConfig) error {
@@ -1111,15 +1176,16 @@ func toRoutes(protoRoutes []*mgmProto.Route) []*route.Route {
 		}
 
 		convertedRoute := &route.Route{
-			ID:          route.ID(protoRoute.ID),
-			Network:     prefix.Masked(),
-			Domains:     domain.FromPunycodeList(protoRoute.Domains),
-			NetID:       route.NetID(protoRoute.NetID),
-			NetworkType: route.NetworkType(protoRoute.NetworkType),
-			Peer:        protoRoute.Peer,
-			Metric:      int(protoRoute.Metric),
-			Masquerade:  protoRoute.Masquerade,
-			KeepRoute:   protoRoute.KeepRoute,
+			ID:            route.ID(protoRoute.ID),
+			Network:       prefix.Masked(),
+			Domains:       domain.FromPunycodeList(protoRoute.Domains),
+			NetID:         route.NetID(protoRoute.NetID),
+			NetworkType:   route.NetworkType(protoRoute.NetworkType),
+			Peer:          protoRoute.Peer,
+			Metric:        int(protoRoute.Metric),
+			Masquerade:    protoRoute.Masquerade,
+			KeepRoute:     protoRoute.KeepRoute,
+			SkipAutoApply: protoRoute.SkipAutoApply,
 		}
 		routes = append(routes, convertedRoute)
 	}
@@ -1285,7 +1351,7 @@ func (e *Engine) createPeerConn(pubKey string, allowedIPs []netip.Prefix, agentV
 			StunTurn:             &e.stunTurn,
 			InterfaceBlackList:   e.config.IFaceBlackList,
 			DisableIPv6Discovery: e.config.DisableIPv6Discovery,
-			UDPMux:               e.udpMux.UDPMuxDefault,
+			UDPMux:               e.udpMux.SingleSocketUDPMux,
 			UDPMuxSrflx:          e.udpMux,
 			NATExternalIPs:       e.parseNATExternalIPMappings(),
 		},
@@ -1491,7 +1557,7 @@ func (e *Engine) newWgIface() (*iface.WGIface, error) {
 		Address:      e.config.WgAddr,
 		WGPort:       e.config.WgPort,
 		WGPrivKey:    e.config.WgPrivateKey.String(),
-		MTU:          iface.DefaultMTU,
+		MTU:          e.config.MTU,
 		TransportNet: transportNet,
 		FilterFn:     e.addrViaRoutes,
 		DisableDNS:   e.config.DisableDNS,
@@ -1550,7 +1616,14 @@ func (e *Engine) newDnsServer(dnsConfig *nbdns.Config) (dns.Server, error) {
 		return dnsServer, nil
 
 	default:
-		dnsServer, err := dns.NewDefaultServer(e.ctx, e.wgInterface, e.config.CustomDNSAddress, e.statusRecorder, e.stateManager, e.config.DisableDNS)
+
+		dnsServer, err := dns.NewDefaultServer(e.ctx, dns.DefaultServerConfig{
+			WgInterface:    e.wgInterface,
+			CustomAddress:  e.config.CustomDNSAddress,
+			StatusRecorder: e.statusRecorder,
+			StateManager:   e.stateManager,
+			DisableSys:     e.config.DisableDNS,
+		})
 		if err != nil {
 			return nil, err
 		}

client/internal/engine_test.go

@@ -19,21 +19,18 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"go.opentelemetry.io/otel"
+	wgdevice "golang.zx2c4.com/wireguard/device"
+	"golang.zx2c4.com/wireguard/tun/netstack"
 	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/keepalive"
 
-	wgdevice "golang.zx2c4.com/wireguard/device"
-	"golang.zx2c4.com/wireguard/tun/netstack"
-
 	"github.com/netbirdio/management-integrations/integrations"
-	"github.com/netbirdio/netbird/management/internals/server/config"
-	"github.com/netbirdio/netbird/management/server/groups"
 
 	"github.com/netbirdio/netbird/client/iface"
-	"github.com/netbirdio/netbird/client/iface/bind"
 	"github.com/netbirdio/netbird/client/iface/configurer"
 	"github.com/netbirdio/netbird/client/iface/device"
+	"github.com/netbirdio/netbird/client/iface/udpmux"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
 	"github.com/netbirdio/netbird/client/iface/wgproxy"
 	"github.com/netbirdio/netbird/client/internal/dns"
@@ -45,9 +42,12 @@ import (
 	"github.com/netbirdio/netbird/client/ssh"
 	"github.com/netbirdio/netbird/client/system"
 	nbdns "github.com/netbirdio/netbird/dns"
+	"github.com/netbirdio/netbird/management/internals/server/config"
 	"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/permissions"
 	"github.com/netbirdio/netbird/management/server/settings"
 	"github.com/netbirdio/netbird/management/server/store"
@@ -85,7 +85,7 @@ type MockWGIface struct {
 	NameFunc                   func() string
 	AddressFunc                func() wgaddr.Address
 	ToInterfaceFunc            func() *net.Interface
-	UpFunc                     func() (*bind.UniversalUDPMuxDefault, error)
+	UpFunc                     func() (*udpmux.UniversalUDPMuxDefault, error)
 	UpdateAddrFunc             func(newAddr string) error
 	UpdatePeerFunc             func(peerKey string, allowedIps []netip.Prefix, keepAlive time.Duration, endpoint *net.UDPAddr, preSharedKey *wgtypes.Key) error
 	RemovePeerFunc             func(peerKey string) error
@@ -135,7 +135,7 @@ func (m *MockWGIface) ToInterface() *net.Interface {
 	return m.ToInterfaceFunc()
 }
 
-func (m *MockWGIface) Up() (*bind.UniversalUDPMuxDefault, error) {
+func (m *MockWGIface) Up() (*udpmux.UniversalUDPMuxDefault, error) {
 	return m.UpFunc()
 }
 
@@ -218,7 +218,7 @@ func TestEngine_SSH(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	relayMgr := relayClient.NewManager(ctx, nil, key.PublicKey().String())
+	relayMgr := relayClient.NewManager(ctx, nil, key.PublicKey().String(), iface.DefaultMTU)
 	engine := NewEngine(
 		ctx, cancel,
 		&signal.MockClient{},
@@ -230,6 +230,7 @@ func TestEngine_SSH(t *testing.T) {
 			WgPrivateKey:     key,
 			WgPort:           33100,
 			ServerSSHAllowed: true,
+			MTU:              iface.DefaultMTU,
 		},
 		MobileDependency{},
 		peer.NewRecorder("https://mgm"),
@@ -265,7 +266,7 @@ func TestEngine_SSH(t *testing.T) {
 			},
 		}, nil
 	}
-	err = engine.Start()
+	err = engine.Start(nil, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -363,7 +364,7 @@ func TestEngine_UpdateNetworkMap(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	relayMgr := relayClient.NewManager(ctx, nil, key.PublicKey().String())
+	relayMgr := relayClient.NewManager(ctx, nil, key.PublicKey().String(), iface.DefaultMTU)
 	engine := NewEngine(
 		ctx, cancel,
 		&signal.MockClient{},
@@ -374,6 +375,7 @@ func TestEngine_UpdateNetworkMap(t *testing.T) {
 			WgAddr:       "100.64.0.1/24",
 			WgPrivateKey: key,
 			WgPort:       33100,
+			MTU:          iface.DefaultMTU,
 		},
 		MobileDependency{},
 		peer.NewRecorder("https://mgm"),
@@ -412,7 +414,7 @@ func TestEngine_UpdateNetworkMap(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	engine.udpMux = bind.NewUniversalUDPMuxDefault(bind.UniversalUDPMuxParams{UDPConn: conn})
+	engine.udpMux = udpmux.NewUniversalUDPMuxDefault(udpmux.UniversalUDPMuxParams{UDPConn: conn, MTU: 1280})
 	engine.ctx = ctx
 	engine.srWatcher = guard.NewSRWatcher(nil, nil, nil, icemaker.Config{})
 	engine.connMgr = NewConnMgr(engine.config, engine.statusRecorder, engine.peerStore, wgIface)
@@ -589,12 +591,13 @@ func TestEngine_Sync(t *testing.T) {
 		}
 		return nil
 	}
-	relayMgr := relayClient.NewManager(ctx, nil, key.PublicKey().String())
+	relayMgr := relayClient.NewManager(ctx, nil, key.PublicKey().String(), iface.DefaultMTU)
 	engine := NewEngine(ctx, cancel, &signal.MockClient{}, &mgmt.MockClient{SyncFunc: syncFunc}, relayMgr, &EngineConfig{
 		WgIfaceName:  "utun103",
 		WgAddr:       "100.64.0.1/24",
 		WgPrivateKey: key,
 		WgPort:       33100,
+		MTU:          iface.DefaultMTU,
 	}, MobileDependency{}, peer.NewRecorder("https://mgm"), nil)
 	engine.ctx = ctx
 
@@ -609,7 +612,7 @@ func TestEngine_Sync(t *testing.T) {
 		}
 	}()
 
-	err = engine.Start()
+	err = engine.Start(nil, nil)
 	if err != nil {
 		t.Fatal(err)
 		return
@@ -753,12 +756,13 @@ func TestEngine_UpdateNetworkMapWithRoutes(t *testing.T) {
 			wgIfaceName := fmt.Sprintf("utun%d", 104+n)
 			wgAddr := fmt.Sprintf("100.66.%d.1/24", n)
 
-			relayMgr := relayClient.NewManager(ctx, nil, key.PublicKey().String())
+			relayMgr := relayClient.NewManager(ctx, nil, key.PublicKey().String(), iface.DefaultMTU)
 			engine := NewEngine(ctx, cancel, &signal.MockClient{}, &mgmt.MockClient{}, relayMgr, &EngineConfig{
 				WgIfaceName:  wgIfaceName,
 				WgAddr:       wgAddr,
 				WgPrivateKey: key,
 				WgPort:       33100,
+				MTU:          iface.DefaultMTU,
 			}, MobileDependency{}, peer.NewRecorder("https://mgm"), nil)
 			engine.ctx = ctx
 			newNet, err := stdnet.NewNet()
@@ -954,12 +958,13 @@ func TestEngine_UpdateNetworkMapWithDNSUpdate(t *testing.T) {
 			wgIfaceName := fmt.Sprintf("utun%d", 104+n)
 			wgAddr := fmt.Sprintf("100.66.%d.1/24", n)
 
-			relayMgr := relayClient.NewManager(ctx, nil, key.PublicKey().String())
+			relayMgr := relayClient.NewManager(ctx, nil, key.PublicKey().String(), iface.DefaultMTU)
 			engine := NewEngine(ctx, cancel, &signal.MockClient{}, &mgmt.MockClient{}, relayMgr, &EngineConfig{
 				WgIfaceName:  wgIfaceName,
 				WgAddr:       wgAddr,
 				WgPrivateKey: key,
 				WgPort:       33100,
+				MTU:          iface.DefaultMTU,
 			}, MobileDependency{}, peer.NewRecorder("https://mgm"), nil)
 			engine.ctx = ctx
 
@@ -1064,7 +1069,7 @@ func TestEngine_MultiplePeers(t *testing.T) {
 			defer mu.Unlock()
 			guid := fmt.Sprintf("{%s}", uuid.New().String())
 			device.CustomWindowsGUIDString = strings.ToLower(guid)
-			err = engine.Start()
+			err = engine.Start(nil, nil)
 			if err != nil {
 				t.Errorf("unable to start engine for peer %d with error %v", j, err)
 				wg.Done()
@@ -1181,6 +1186,7 @@ func Test_ParseNATExternalIPMappings(t *testing.T) {
 				config: &EngineConfig{
 					IFaceBlackList: testCase.inputBlacklistInterface,
 					NATExternalIPs: testCase.inputMapList,
+					MTU:            iface.DefaultMTU,
 				},
 			}
 			parsedList := engine.parseNATExternalIPMappings()
@@ -1481,9 +1487,10 @@ func createEngine(ctx context.Context, cancel context.CancelFunc, setupKey strin
 		WgAddr:       resp.PeerConfig.Address,
 		WgPrivateKey: key,
 		WgPort:       wgPort,
+		MTU:          iface.DefaultMTU,
 	}
 
-	relayMgr := relayClient.NewManager(ctx, nil, key.PublicKey().String())
+	relayMgr := relayClient.NewManager(ctx, nil, key.PublicKey().String(), iface.DefaultMTU)
 	e, err := NewEngine(ctx, cancel, signalClient, mgmtClient, relayMgr, conf, MobileDependency{}, peer.NewRecorder("https://mgm"), nil), nil
 	e.ctx = ctx
 	return e, err
@@ -1548,7 +1555,11 @@ func startManagement(t *testing.T, dataDir, testFile string) (*grpc.Server, stri
 	if err != nil {
 		return nil, "", err
 	}
-	ia, _ := integrations.NewIntegratedValidator(context.Background(), eventStore)
+
+	permissionsManager := permissions.NewManager(store)
+	peersManager := peers.NewManager(store, permissionsManager)
+
+	ia, _ := integrations.NewIntegratedValidator(context.Background(), peersManager, nil, eventStore)
 
 	metrics, err := telemetry.NewDefaultAppMetrics(context.Background())
 	require.NoError(t, err)
@@ -1565,7 +1576,6 @@ func startManagement(t *testing.T, dataDir, testFile string) (*grpc.Server, stri
 		Return(&types.ExtraSettings{}, nil).
 		AnyTimes()
 
-	permissionsManager := permissions.NewManager(store)
 	groupsManager := groups.NewManagerMock()
 
 	accountManager, err := server.BuildManager(context.Background(), store, peersUpdateManager, nil, "", "netbird.selfhosted", eventStore, nil, false, ia, metrics, port_forwarding.NewControllerMock(), settingsMockManager, permissionsManager, false)

client/internal/iface_common.go

@@ -9,9 +9,9 @@ import (
 	"golang.zx2c4.com/wireguard/tun/netstack"
 	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
 
-	"github.com/netbirdio/netbird/client/iface/bind"
 	"github.com/netbirdio/netbird/client/iface/configurer"
 	"github.com/netbirdio/netbird/client/iface/device"
+	"github.com/netbirdio/netbird/client/iface/udpmux"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
 	"github.com/netbirdio/netbird/client/iface/wgproxy"
 	"github.com/netbirdio/netbird/monotime"
@@ -24,7 +24,7 @@ type wgIfaceBase interface {
 	Name() string
 	Address() wgaddr.Address
 	ToInterface() *net.Interface
-	Up() (*bind.UniversalUDPMuxDefault, error)
+	Up() (*udpmux.UniversalUDPMuxDefault, error)
 	UpdateAddr(newAddr string) error
 	GetProxy() wgproxy.Proxy
 	UpdatePeer(peerKey string, allowedIps []netip.Prefix, keepAlive time.Duration, endpoint *net.UDPAddr, preSharedKey *wgtypes.Key) error

client/internal/login.go

@@ -40,7 +40,7 @@ func IsLoginRequired(ctx context.Context, config *profilemanager.Config) (bool,
 		return false, err
 	}
 
-	_, err = doMgmLogin(ctx, mgmClient, pubSSHKey, config)
+	_, _, err = doMgmLogin(ctx, mgmClient, pubSSHKey, config)
 	if isLoginNeeded(err) {
 		return true, nil
 	}
@@ -69,14 +69,18 @@ func Login(ctx context.Context, config *profilemanager.Config, setupKey string,
 		return err
 	}
 
-	serverKey, err := doMgmLogin(ctx, mgmClient, pubSSHKey, config)
+	serverKey, _, err := doMgmLogin(ctx, mgmClient, pubSSHKey, config)
 	if serverKey != nil && isRegistrationNeeded(err) {
 		log.Debugf("peer registration required")
 		_, err = registerPeer(ctx, *serverKey, mgmClient, setupKey, jwtToken, pubSSHKey, config)
+		if err != nil {
+			return err
+		}
+	} else if err != nil {
 		return err
 	}
 
-	return err
+	return nil
 }
 
 func getMgmClient(ctx context.Context, privateKey string, mgmURL *url.URL) (*mgm.GrpcClient, error) {
@@ -101,11 +105,11 @@ func getMgmClient(ctx context.Context, privateKey string, mgmURL *url.URL) (*mgm
 	return mgmClient, err
 }
 
-func doMgmLogin(ctx context.Context, mgmClient *mgm.GrpcClient, pubSSHKey []byte, config *profilemanager.Config) (*wgtypes.Key, error) {
+func doMgmLogin(ctx context.Context, mgmClient *mgm.GrpcClient, pubSSHKey []byte, config *profilemanager.Config) (*wgtypes.Key, *mgmProto.LoginResponse, error) {
 	serverKey, err := mgmClient.GetServerPublicKey()
 	if err != nil {
 		log.Errorf("failed while getting Management Service public key: %v", err)
-		return nil, err
+		return nil, nil, err
 	}
 
 	sysInfo := system.GetInfo(ctx)
@@ -121,8 +125,8 @@ func doMgmLogin(ctx context.Context, mgmClient *mgm.GrpcClient, pubSSHKey []byte
 		config.BlockInbound,
 		config.LazyConnectionEnabled,
 	)
-	_, err = mgmClient.Login(*serverKey, sysInfo, pubSSHKey, config.DNSLabels)
-	return serverKey, err
+	loginResp, err := mgmClient.Login(*serverKey, sysInfo, pubSSHKey, config.DNSLabels)
+	return serverKey, loginResp, err
 }
 
 // registerPeer checks whether setupKey was provided via cmd line and if not then it prompts user to enter a key.

client/internal/netflow/conntrack/conntrack.go

@@ -14,7 +14,7 @@ import (
 	"github.com/ti-mo/netfilter"
 
 	nftypes "github.com/netbirdio/netbird/client/internal/netflow/types"
-	nbnet "github.com/netbirdio/netbird/util/net"
+	nbnet "github.com/netbirdio/netbird/client/net"
 )
 
 const defaultChannelSize = 100

client/internal/peer/conn.go

@@ -6,12 +6,11 @@ import (
 	"math/rand"
 	"net"
 	"net/netip"
-	"os"
 	"runtime"
 	"sync"
 	"time"
 
-	"github.com/pion/ice/v3"
+	"github.com/pion/ice/v4"
 	log "github.com/sirupsen/logrus"
 	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
 
@@ -174,7 +173,7 @@ func (conn *Conn) Open(engineCtx context.Context) error {
 	conn.handshaker = NewHandshaker(conn.Log, conn.config, conn.signaler, conn.workerICE, conn.workerRelay)
 
 	conn.handshaker.AddOnNewOfferListener(conn.workerRelay.OnNewOffer)
-	if os.Getenv("NB_FORCE_RELAY") != "true" {
+	if !isForceRelayed() {
 		conn.handshaker.AddOnNewOfferListener(conn.workerICE.OnNewOffer)
 	}
 

client/internal/peer/env.go

@@ -0,0 +1,14 @@
+package peer
+
+import (
+	"os"
+	"strings"
+)
+
+const (
+	EnvKeyNBForceRelay = "NB_FORCE_RELAY"
+)
+
+func isForceRelayed() bool {
+	return strings.EqualFold(os.Getenv(EnvKeyNBForceRelay), "true")
+}

client/internal/peer/guard/ice_monitor.go

@@ -6,7 +6,7 @@ import (
 	"sync"
 	"time"
 
-	"github.com/pion/ice/v3"
+	"github.com/pion/ice/v4"
 	log "github.com/sirupsen/logrus"
 
 	icemaker "github.com/netbirdio/netbird/client/internal/peer/ice"

client/internal/peer/handshaker.go

@@ -43,13 +43,6 @@ type OfferAnswer struct {
 	SessionID *ICESessionID
 }
 
-func (oa *OfferAnswer) SessionIDString() string {
-	if oa.SessionID == nil {
-		return "unknown"
-	}
-	return oa.SessionID.String()
-}
-
 type Handshaker struct {
 	mu                  sync.Mutex
 	log                 *log.Entry
@@ -57,7 +50,7 @@ type Handshaker struct {
 	signaler            *Signaler
 	ice                 *WorkerICE
 	relay               *WorkerRelay
-	onNewOfferListeners []func(*OfferAnswer)
+	onNewOfferListeners []*OfferListener
 
 	// remoteOffersCh is a channel used to wait for remote credentials to proceed with the connection
 	remoteOffersCh chan OfferAnswer
@@ -78,7 +71,8 @@ func NewHandshaker(log *log.Entry, config ConnConfig, signaler *Signaler, ice *W
 }
 
 func (h *Handshaker) AddOnNewOfferListener(offer func(remoteOfferAnswer *OfferAnswer)) {
-	h.onNewOfferListeners = append(h.onNewOfferListeners, offer)
+	l := NewOfferListener(offer)
+	h.onNewOfferListeners = append(h.onNewOfferListeners, l)
 }
 
 func (h *Handshaker) Listen(ctx context.Context) {
@@ -91,13 +85,13 @@ func (h *Handshaker) Listen(ctx context.Context) {
 				continue
 			}
 			for _, listener := range h.onNewOfferListeners {
-				listener(&remoteOfferAnswer)
+				listener.Notify(&remoteOfferAnswer)
 			}
 			h.log.Infof("received offer, running version %s, remote WireGuard listen port %d, session id: %s", remoteOfferAnswer.Version, remoteOfferAnswer.WgListenPort, remoteOfferAnswer.SessionIDString())
 		case remoteOfferAnswer := <-h.remoteAnswerCh:
 			h.log.Infof("received answer, running version %s, remote WireGuard listen port %d, session id: %s", remoteOfferAnswer.Version, remoteOfferAnswer.WgListenPort, remoteOfferAnswer.SessionIDString())
 			for _, listener := range h.onNewOfferListeners {
-				listener(&remoteOfferAnswer)
+				listener.Notify(&remoteOfferAnswer)
 			}
 		case <-ctx.Done():
 			h.log.Infof("stop listening for remote offers and answers")

client/internal/peer/handshaker_listener.go

@@ -0,0 +1,62 @@
+package peer
+
+import (
+	"sync"
+)
+
+type callbackFunc func(remoteOfferAnswer *OfferAnswer)
+
+func (oa *OfferAnswer) SessionIDString() string {
+	if oa.SessionID == nil {
+		return "unknown"
+	}
+	return oa.SessionID.String()
+}
+
+type OfferListener struct {
+	fn      callbackFunc
+	running bool
+	latest  *OfferAnswer
+	mu      sync.Mutex
+}
+
+func NewOfferListener(fn callbackFunc) *OfferListener {
+	return &OfferListener{
+		fn: fn,
+	}
+}
+
+func (o *OfferListener) Notify(remoteOfferAnswer *OfferAnswer) {
+	o.mu.Lock()
+	defer o.mu.Unlock()
+
+	// Store the latest offer
+	o.latest = remoteOfferAnswer
+
+	// If already running, the running goroutine will pick up this latest value
+	if o.running {
+		return
+	}
+
+	// Start processing
+	o.running = true
+
+	// Process in a goroutine to avoid blocking the caller
+	go func(remoteOfferAnswer *OfferAnswer) {
+		for {
+			o.fn(remoteOfferAnswer)
+
+			o.mu.Lock()
+			if o.latest == nil {
+				// No more work to do
+				o.running = false
+				o.mu.Unlock()
+				return
+			}
+			remoteOfferAnswer = o.latest
+			// Clear the latest to mark it as being processed
+			o.latest = nil
+			o.mu.Unlock()
+		}
+	}(remoteOfferAnswer)
+}

client/internal/peer/handshaker_listener_test.go

@@ -0,0 +1,39 @@
+package peer
+
+import (
+	"testing"
+	"time"
+)
+
+func Test_newOfferListener(t *testing.T) {
+	dummyOfferAnswer := &OfferAnswer{}
+	runChan := make(chan struct{}, 10)
+
+	longRunningFn := func(remoteOfferAnswer *OfferAnswer) {
+		time.Sleep(1 * time.Second)
+		runChan <- struct{}{}
+	}
+
+	hl := NewOfferListener(longRunningFn)
+
+	hl.Notify(dummyOfferAnswer)
+	hl.Notify(dummyOfferAnswer)
+	hl.Notify(dummyOfferAnswer)
+
+	// Wait for exactly 2 callbacks
+	for i := 0; i < 2; i++ {
+		select {
+		case <-runChan:
+		case <-time.After(3 * time.Second):
+			t.Fatal("Timeout waiting for callback")
+		}
+	}
+
+	// Verify no additional callbacks happen
+	select {
+	case <-runChan:
+		t.Fatal("Unexpected additional callback")
+	case <-time.After(100 * time.Millisecond):
+		t.Log("Correctly received exactly 2 callbacks")
+	}
+}

client/internal/peer/ice/StunTurn.go

@@ -3,7 +3,7 @@ package ice
 import (
 	"sync/atomic"
 
-	"github.com/pion/stun/v2"
+	"github.com/pion/stun/v3"
 )
 
 type StunTurn atomic.Value

client/internal/peer/ice/agent.go

@@ -1,9 +1,10 @@
 package ice
 
 import (
+	"sync"
 	"time"
 
-	"github.com/pion/ice/v3"
+	"github.com/pion/ice/v4"
 	"github.com/pion/logging"
 	"github.com/pion/randutil"
 	log "github.com/sirupsen/logrus"
@@ -23,7 +24,20 @@ const (
 	iceRelayAcceptanceMinWaitDefault = 2 * time.Second
 )
 
-func NewAgent(iFaceDiscover stdnet.ExternalIFaceDiscover, config Config, candidateTypes []ice.CandidateType, ufrag string, pwd string) (*ice.Agent, error) {
+type ThreadSafeAgent struct {
+	*ice.Agent
+	once sync.Once
+}
+
+func (a *ThreadSafeAgent) Close() error {
+	var err error
+	a.once.Do(func() {
+		err = a.Agent.Close()
+	})
+	return err
+}
+
+func NewAgent(iFaceDiscover stdnet.ExternalIFaceDiscover, config Config, candidateTypes []ice.CandidateType, ufrag string, pwd string) (*ThreadSafeAgent, error) {
 	iceKeepAlive := iceKeepAlive()
 	iceDisconnectedTimeout := iceDisconnectedTimeout()
 	iceFailedTimeout := iceFailedTimeout()
@@ -61,7 +75,12 @@ func NewAgent(iFaceDiscover stdnet.ExternalIFaceDiscover, config Config, candida
 		agentConfig.NetworkTypes = []ice.NetworkType{ice.NetworkTypeUDP4}
 	}
 
-	return ice.NewAgent(agentConfig)
+	agent, err := ice.NewAgent(agentConfig)
+	if err != nil {
+		return nil, err
+	}
+
+	return &ThreadSafeAgent{Agent: agent}, nil
 }
 
 func GenerateICECredentials() (string, string, error) {

client/internal/peer/ice/config.go

@@ -1,7 +1,7 @@
 package ice
 
 import (
-	"github.com/pion/ice/v3"
+	"github.com/pion/ice/v4"
 )
 
 type Config struct {

client/internal/peer/signaler.go

@@ -1,7 +1,7 @@
 package peer
 
 import (
-	"github.com/pion/ice/v3"
+	"github.com/pion/ice/v4"
 	log "github.com/sirupsen/logrus"
 	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
 

client/internal/peer/wg_watcher.go

@@ -30,9 +30,10 @@ type WGWatcher struct {
 	peerKey       string
 	stateDump     *stateDump
 
-	ctx       context.Context
-	ctxCancel context.CancelFunc
-	ctxLock   sync.Mutex
+	ctx         context.Context
+	ctxCancel   context.CancelFunc
+	ctxLock     sync.Mutex
+	enabledTime time.Time
 }
 
 func NewWGWatcher(log *log.Entry, wgIfaceStater WGInterfaceStater, peerKey string, stateDump *stateDump) *WGWatcher {
@@ -48,6 +49,7 @@ func NewWGWatcher(log *log.Entry, wgIfaceStater WGInterfaceStater, peerKey strin
 func (w *WGWatcher) EnableWgWatcher(parentCtx context.Context, onDisconnectedFn func()) {
 	w.log.Debugf("enable WireGuard watcher")
 	w.ctxLock.Lock()
+	w.enabledTime = time.Now()
 
 	if w.ctx != nil && w.ctx.Err() == nil {
 		w.log.Errorf("WireGuard watcher already enabled")
@@ -101,6 +103,11 @@ func (w *WGWatcher) periodicHandshakeCheck(ctx context.Context, ctxCancel contex
 				onDisconnectedFn()
 				return
 			}
+			if lastHandshake.IsZero() {
+				elapsed := handshake.Sub(w.enabledTime).Seconds()
+				w.log.Infof("first wg handshake detected within: %.2fsec, (%s)", elapsed, handshake)
+			}
+
 			lastHandshake = *handshake
 
 			resetTime := time.Until(handshake.Add(checkPeriod))

client/internal/peer/worker_ice.go

@@ -8,12 +8,11 @@ import (
 	"sync"
 	"time"
 
-	"github.com/pion/ice/v3"
-	"github.com/pion/stun/v2"
+	"github.com/pion/ice/v4"
 	log "github.com/sirupsen/logrus"
 
 	"github.com/netbirdio/netbird/client/iface"
-	"github.com/netbirdio/netbird/client/iface/bind"
+	"github.com/netbirdio/netbird/client/iface/udpmux"
 	"github.com/netbirdio/netbird/client/internal/peer/conntype"
 	icemaker "github.com/netbirdio/netbird/client/internal/peer/ice"
 	"github.com/netbirdio/netbird/client/internal/stdnet"
@@ -42,7 +41,7 @@ type WorkerICE struct {
 	statusRecorder    *Status
 	hasRelayOnLocally bool
 
-	agent             *ice.Agent
+	agent             *icemaker.ThreadSafeAgent
 	agentDialerCancel context.CancelFunc
 	agentConnecting   bool      // while it is true, drop all incoming offers
 	lastSuccess       time.Time // with this avoid the too frequent ICE agent recreation
@@ -55,10 +54,6 @@ type WorkerICE struct {
 	sessionID ICESessionID
 	muxAgent  sync.Mutex
 
-	StunTurn []*stun.URI
-
-	sentExtraSrflx bool
-
 	localUfrag string
 	localPwd   string
 
@@ -121,7 +116,7 @@ func (w *WorkerICE) OnNewOffer(remoteOfferAnswer *OfferAnswer) {
 		if err := w.agent.Close(); err != nil {
 			w.log.Warnf("failed to close ICE agent: %s", err)
 		}
-		// todo consider to switch to Relay connection while establishing a new ICE connection
+		w.agent = nil
 	}
 
 	var preferredCandidateTypes []ice.CandidateType
@@ -139,7 +134,6 @@ func (w *WorkerICE) OnNewOffer(remoteOfferAnswer *OfferAnswer) {
 		w.muxAgent.Unlock()
 		return
 	}
-	w.sentExtraSrflx = false
 	w.agent = agent
 	w.agentDialerCancel = dialerCancel
 	w.agentConnecting = true
@@ -166,6 +160,21 @@ func (w *WorkerICE) OnRemoteCandidate(candidate ice.Candidate, haRoutes route.HA
 		w.log.Errorf("error while handling remote candidate")
 		return
 	}
+
+	if shouldAddExtraCandidate(candidate) {
+		// sends an extra server reflexive candidate to the remote peer with our related port (usually the wireguard port)
+		// this is useful when network has an existing port forwarding rule for the wireguard port and this peer
+		extraSrflx, err := extraSrflxCandidate(candidate)
+		if err != nil {
+			w.log.Errorf("failed creating extra server reflexive candidate %s", err)
+			return
+		}
+
+		if err := w.agent.AddRemoteCandidate(extraSrflx); err != nil {
+			w.log.Errorf("error while handling remote candidate")
+			return
+		}
+	}
 }
 
 func (w *WorkerICE) GetLocalUserCredentials() (frag string, pwd string) {
@@ -195,7 +204,7 @@ func (w *WorkerICE) Close() {
 	w.agent = nil
 }
 
-func (w *WorkerICE) reCreateAgent(dialerCancel context.CancelFunc, candidates []ice.CandidateType) (*ice.Agent, error) {
+func (w *WorkerICE) reCreateAgent(dialerCancel context.CancelFunc, candidates []ice.CandidateType) (*icemaker.ThreadSafeAgent, error) {
 	agent, err := icemaker.NewAgent(w.iFaceDiscover, w.config.ICEConfig, candidates, w.localUfrag, w.localPwd)
 	if err != nil {
 		return nil, fmt.Errorf("create agent: %w", err)
@@ -209,14 +218,12 @@ func (w *WorkerICE) reCreateAgent(dialerCancel context.CancelFunc, candidates []
 		return nil, err
 	}
 
-	if err := agent.OnSelectedCandidatePairChange(w.onICESelectedCandidatePair); err != nil {
+	if err := agent.OnSelectedCandidatePairChange(func(c1, c2 ice.Candidate) {
+		w.onICESelectedCandidatePair(agent, c1, c2)
+	}); err != nil {
 		return nil, err
 	}
 
-	if err := agent.OnSuccessfulSelectedPairBindingResponse(w.onSuccessfulSelectedPairBindingResponse); err != nil {
-		return nil, fmt.Errorf("failed setting binding response callback: %w", err)
-	}
-
 	return agent, nil
 }
 
@@ -230,7 +237,7 @@ func (w *WorkerICE) SessionID() ICESessionID {
 // will block until connection succeeded
 // but it won't release if ICE Agent went into Disconnected or Failed state,
 // so we have to cancel it with the provided context once agent detected a broken connection
-func (w *WorkerICE) connect(ctx context.Context, agent *ice.Agent, remoteOfferAnswer *OfferAnswer) {
+func (w *WorkerICE) connect(ctx context.Context, agent *icemaker.ThreadSafeAgent, remoteOfferAnswer *OfferAnswer) {
 	w.log.Debugf("gather candidates")
 	if err := agent.GatherCandidates(); err != nil {
 		w.log.Warnf("failed to gather candidates: %s", err)
@@ -239,7 +246,7 @@ func (w *WorkerICE) connect(ctx context.Context, agent *ice.Agent, remoteOfferAn
 	}
 
 	w.log.Debugf("turn agent dial")
-	remoteConn, err := w.turnAgentDial(ctx, remoteOfferAnswer)
+	remoteConn, err := w.turnAgentDial(ctx, agent, remoteOfferAnswer)
 	if err != nil {
 		w.log.Debugf("failed to dial the remote peer: %s", err)
 		w.closeAgent(agent, w.agentDialerCancel)
@@ -252,6 +259,11 @@ func (w *WorkerICE) connect(ctx context.Context, agent *ice.Agent, remoteOfferAn
 		w.closeAgent(agent, w.agentDialerCancel)
 		return
 	}
+	if pair == nil {
+		w.log.Warnf("selected candidate pair is nil, cannot proceed")
+		w.closeAgent(agent, w.agentDialerCancel)
+		return
+	}
 
 	if !isRelayCandidate(pair.Local) {
 		// dynamically set remote WireGuard port if other side specified a different one from the default one
@@ -290,13 +302,14 @@ func (w *WorkerICE) connect(ctx context.Context, agent *ice.Agent, remoteOfferAn
 	w.conn.onICEConnectionIsReady(selectedPriority(pair), ci)
 }
 
-func (w *WorkerICE) closeAgent(agent *ice.Agent, cancel context.CancelFunc) {
+func (w *WorkerICE) closeAgent(agent *icemaker.ThreadSafeAgent, cancel context.CancelFunc) {
 	cancel()
 	if err := agent.Close(); err != nil {
 		w.log.Warnf("failed to close ICE agent: %s", err)
 	}
 
 	w.muxAgent.Lock()
+	// todo review does it make sense to generate new session ID all the time when w.agent==agent
 	sessionID, err := NewICESessionID()
 	if err != nil {
 		w.log.Errorf("failed to create new session ID: %s", err)
@@ -325,7 +338,7 @@ func (w *WorkerICE) punchRemoteWGPort(pair *ice.CandidatePair, remoteWgPort int)
 		return
 	}
 
-	mux, ok := w.config.ICEConfig.UDPMuxSrflx.(*bind.UniversalUDPMuxDefault)
+	mux, ok := w.config.ICEConfig.UDPMuxSrflx.(*udpmux.UniversalUDPMuxDefault)
 	if !ok {
 		w.log.Warn("invalid udp mux conversion")
 		return
@@ -352,41 +365,36 @@ func (w *WorkerICE) onICECandidate(candidate ice.Candidate) {
 			w.log.Errorf("failed signaling candidate to the remote peer %s %s", w.config.Key, err)
 		}
 	}()
-
-	if !w.shouldSendExtraSrflxCandidate(candidate) {
-		return
-	}
-
-	// sends an extra server reflexive candidate to the remote peer with our related port (usually the wireguard port)
-	// this is useful when network has an existing port forwarding rule for the wireguard port and this peer
-	extraSrflx, err := extraSrflxCandidate(candidate)
-	if err != nil {
-		w.log.Errorf("failed creating extra server reflexive candidate %s", err)
-		return
-	}
-	w.sentExtraSrflx = true
-
-	go func() {
-		err = w.signaler.SignalICECandidate(extraSrflx, w.config.Key)
-		if err != nil {
-			w.log.Errorf("failed signaling the extra server reflexive candidate: %s", err)
-		}
-	}()
 }
 
-func (w *WorkerICE) onICESelectedCandidatePair(c1 ice.Candidate, c2 ice.Candidate) {
+func (w *WorkerICE) onICESelectedCandidatePair(agent *icemaker.ThreadSafeAgent, c1, c2 ice.Candidate) {
 	w.log.Debugf("selected candidate pair [local <-> remote] -> [%s <-> %s], peer %s", c1.String(), c2.String(),
 		w.config.Key)
+
+	pairStat, ok := agent.GetSelectedCandidatePairStats()
+	if !ok {
+		w.log.Warnf("failed to get selected candidate pair stats")
+		return
+	}
+
+	duration := time.Duration(pairStat.CurrentRoundTripTime * float64(time.Second))
+	if err := w.statusRecorder.UpdateLatency(w.config.Key, duration); err != nil {
+		w.log.Debugf("failed to update latency for peer: %s", err)
+		return
+	}
 }
 
-func (w *WorkerICE) onConnectionStateChange(agent *ice.Agent, dialerCancel context.CancelFunc) func(ice.ConnectionState) {
+func (w *WorkerICE) onConnectionStateChange(agent *icemaker.ThreadSafeAgent, dialerCancel context.CancelFunc) func(ice.ConnectionState) {
 	return func(state ice.ConnectionState) {
 		w.log.Debugf("ICE ConnectionState has changed to %s", state.String())
 		switch state {
 		case ice.ConnectionStateConnected:
 			w.lastKnownState = ice.ConnectionStateConnected
 			return
-		case ice.ConnectionStateFailed, ice.ConnectionStateDisconnected:
+		case ice.ConnectionStateFailed, ice.ConnectionStateDisconnected, ice.ConnectionStateClosed:
+			// ice.ConnectionStateClosed happens when we recreate the agent. For the P2P to TURN switch important to
+			// notify the conn.onICEStateDisconnected changes to update the current used priority
+
 			if w.lastKnownState == ice.ConnectionStateConnected {
 				w.lastKnownState = ice.ConnectionStateDisconnected
 				w.conn.onICEStateDisconnected()
@@ -398,32 +406,34 @@ func (w *WorkerICE) onConnectionStateChange(agent *ice.Agent, dialerCancel conte
 	}
 }
 
-func (w *WorkerICE) onSuccessfulSelectedPairBindingResponse(pair *ice.CandidatePair) {
-	if err := w.statusRecorder.UpdateLatency(w.config.Key, pair.Latency()); err != nil {
-		w.log.Debugf("failed to update latency for peer: %s", err)
-		return
-	}
-}
-
-func (w *WorkerICE) shouldSendExtraSrflxCandidate(candidate ice.Candidate) bool {
-	if !w.sentExtraSrflx && candidate.Type() == ice.CandidateTypeServerReflexive && candidate.Port() != candidate.RelatedAddress().Port {
-		return true
-	}
-	return false
-}
-
-func (w *WorkerICE) turnAgentDial(ctx context.Context, remoteOfferAnswer *OfferAnswer) (*ice.Conn, error) {
-	isControlling := w.config.LocalKey > w.config.Key
-	if isControlling {
+func (w *WorkerICE) turnAgentDial(ctx context.Context, agent *icemaker.ThreadSafeAgent, remoteOfferAnswer *OfferAnswer) (*ice.Conn, error) {
+	if isController(w.config) {
 		return w.agent.Dial(ctx, remoteOfferAnswer.IceCredentials.UFrag, remoteOfferAnswer.IceCredentials.Pwd)
 	} else {
-		return w.agent.Accept(ctx, remoteOfferAnswer.IceCredentials.UFrag, remoteOfferAnswer.IceCredentials.Pwd)
+		return agent.Accept(ctx, remoteOfferAnswer.IceCredentials.UFrag, remoteOfferAnswer.IceCredentials.Pwd)
 	}
 }
 
+func shouldAddExtraCandidate(candidate ice.Candidate) bool {
+	if candidate.Type() != ice.CandidateTypeServerReflexive {
+		return false
+	}
+
+	if candidate.Port() == candidate.RelatedAddress().Port {
+		return false
+	}
+
+	// in the older version when we didn't set candidate ID extension the remote peer sent the extra candidates
+	// in newer version we generate locally the extra candidate
+	if _, ok := candidate.GetExtension(ice.ExtensionKeyCandidateID); !ok {
+		return false
+	}
+	return true
+}
+
 func extraSrflxCandidate(candidate ice.Candidate) (*ice.CandidateServerReflexive, error) {
 	relatedAdd := candidate.RelatedAddress()
-	return ice.NewCandidateServerReflexive(&ice.CandidateServerReflexiveConfig{
+	ec, err := ice.NewCandidateServerReflexive(&ice.CandidateServerReflexiveConfig{
 		Network:   candidate.NetworkType().String(),
 		Address:   candidate.Address(),
 		Port:      relatedAdd.Port,
@@ -431,6 +441,21 @@ func extraSrflxCandidate(candidate ice.Candidate) (*ice.CandidateServerReflexive
 		RelAddr:   relatedAdd.Address,
 		RelPort:   relatedAdd.Port,
 	})
+	if err != nil {
+		return nil, err
+	}
+
+	for _, e := range candidate.Extensions() {
+		// overwrite the original candidate ID with the new one to avoid candidate duplication
+		if e.Key == ice.ExtensionKeyCandidateID {
+			e.Value = candidate.ID()
+		}
+		if err := ec.AddExtension(e); err != nil {
+			return nil, err
+		}
+	}
+
+	return ec, nil
 }
 
 func candidateViaRoutes(candidate ice.Candidate, clientRoutes route.HAMap) bool {

client/internal/profilemanager/config.go

@@ -75,6 +75,8 @@ type ConfigInput struct {
 	DNSLabels domain.List
 
 	LazyConnectionEnabled *bool
+
+	MTU *uint16
 }
 
 // Config Configuration type
@@ -141,6 +143,8 @@ type Config struct {
 	ClientCertKeyPair *tls.Certificate `json:"-"`
 
 	LazyConnectionEnabled bool
+
+	MTU uint16
 }
 
 var ConfigDirOverride string
@@ -493,6 +497,16 @@ func (config *Config) apply(input ConfigInput) (updated bool, err error) {
 		updated = true
 	}
 
+	if input.MTU != nil && *input.MTU != config.MTU {
+		log.Infof("updating MTU to %d (old value %d)", *input.MTU, config.MTU)
+		config.MTU = *input.MTU
+		updated = true
+	} else if config.MTU == 0 {
+		config.MTU = iface.DefaultMTU
+		log.Infof("using default MTU %d", config.MTU)
+		updated = true
+	}
+
 	return updated, nil
 }
 

client/internal/relay/relay.go

@@ -7,12 +7,12 @@ import (
 	"sync"
 	"time"
 
-	"github.com/pion/stun/v2"
+	"github.com/pion/stun/v3"
 	"github.com/pion/turn/v3"
 	log "github.com/sirupsen/logrus"
 
 	"github.com/netbirdio/netbird/client/internal/stdnet"
-	nbnet "github.com/netbirdio/netbird/util/net"
+	nbnet "github.com/netbirdio/netbird/client/net"
 )
 
 // ProbeResult holds the info about the result of a relay probe request

client/internal/routemanager/dnsinterceptor/handler.go

@@ -2,11 +2,13 @@ package dnsinterceptor
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"net/netip"
 	"runtime"
 	"strings"
 	"sync"
+	"time"
 
 	"github.com/hashicorp/go-multierror"
 	"github.com/miekg/dns"
@@ -26,6 +28,8 @@ import (
 	"github.com/netbirdio/netbird/route"
 )
 
+const dnsTimeout = 8 * time.Second
+
 type domainMap map[domain.Domain][]netip.Prefix
 
 type internalDNATer interface {
@@ -243,7 +247,7 @@ func (d *DnsInterceptor) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
 		return
 	}
 
-	client, err := nbdns.GetClientPrivate(d.wgInterface.Address().IP, d.wgInterface.Name(), nbdns.UpstreamTimeout)
+	client, err := nbdns.GetClientPrivate(d.wgInterface.Address().IP, d.wgInterface.Name(), dnsTimeout)
 	if err != nil {
 		d.writeDNSError(w, r, logger, fmt.Sprintf("create DNS client: %v", err))
 		return
@@ -254,9 +258,20 @@ func (d *DnsInterceptor) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
 	}
 
 	upstream := fmt.Sprintf("%s:%d", upstreamIP.String(), dnsfwd.ListenPort)
-	reply, _, err := nbdns.ExchangeWithFallback(context.TODO(), client, r, upstream)
+	ctx, cancel := context.WithTimeout(context.Background(), dnsTimeout)
+	defer cancel()
+
+	startTime := time.Now()
+	reply, _, err := nbdns.ExchangeWithFallback(ctx, client, r, upstream)
 	if err != nil {
-		logger.Errorf("failed to exchange DNS request with %s (%s) for domain=%s: %v", upstreamIP.String(), peerKey, r.Question[0].Name, err)
+		if errors.Is(err, context.DeadlineExceeded) {
+			elapsed := time.Since(startTime)
+			peerInfo := d.debugPeerTimeout(upstreamIP, peerKey)
+			logger.Errorf("peer DNS timeout after %v (timeout=%v) for domain=%s to peer %s (%s)%s - error: %v",
+				elapsed.Truncate(time.Millisecond), dnsTimeout, r.Question[0].Name, upstreamIP.String(), peerKey, peerInfo, err)
+		} else {
+			logger.Errorf("failed to exchange DNS request with %s (%s) for domain=%s: %v", upstreamIP.String(), peerKey, r.Question[0].Name, err)
+		}
 		if err := w.WriteMsg(&dns.Msg{MsgHdr: dns.MsgHdr{Rcode: dns.RcodeServerFailure, Id: r.Id}}); err != nil {
 			logger.Errorf("failed writing DNS response: %v", err)
 		}
@@ -568,3 +583,16 @@ func determinePrefixChanges(oldPrefixes, newPrefixes []netip.Prefix) (toAdd, toR
 	}
 	return
 }
+
+func (d *DnsInterceptor) debugPeerTimeout(peerIP netip.Addr, peerKey string) string {
+	if d.statusRecorder == nil {
+		return ""
+	}
+
+	peerState, err := d.statusRecorder.GetPeer(peerKey)
+	if err != nil {
+		return fmt.Sprintf(" (peer %s state error: %v)", peerKey[:8], err)
+	}
+
+	return fmt.Sprintf(" (peer %s)", nbdns.FormatPeerStatus(&peerState))
+}

client/internal/routemanager/manager.go

@@ -36,9 +36,9 @@ import (
 	"github.com/netbirdio/netbird/client/internal/routemanager/vars"
 	"github.com/netbirdio/netbird/client/internal/routeselector"
 	"github.com/netbirdio/netbird/client/internal/statemanager"
-	relayClient "github.com/netbirdio/netbird/shared/relay/client"
+	nbnet "github.com/netbirdio/netbird/client/net"
 	"github.com/netbirdio/netbird/route"
-	nbnet "github.com/netbirdio/netbird/util/net"
+	relayClient "github.com/netbirdio/netbird/shared/relay/client"
 	"github.com/netbirdio/netbird/version"
 )
 
@@ -108,6 +108,10 @@ func NewManager(config ManagerConfig) *DefaultManager {
 	notifier := notifier.NewNotifier()
 	sysOps := systemops.NewSysOps(config.WGInterface, notifier)
 
+	if runtime.GOOS == "windows" && config.WGInterface != nil {
+		nbnet.SetVPNInterfaceName(config.WGInterface.Name())
+	}
+
 	dm := &DefaultManager{
 		ctx:                 mCTX,
 		stop:                cancel,
@@ -208,7 +212,7 @@ func (m *DefaultManager) Init() error {
 		return nil
 	}
 
-	if err := m.sysOps.CleanupRouting(nil); err != nil {
+	if err := m.sysOps.CleanupRouting(nil, nbnet.AdvancedRouting()); err != nil {
 		log.Warnf("Failed cleaning up routing: %v", err)
 	}
 
@@ -219,7 +223,7 @@ func (m *DefaultManager) Init() error {
 
 	ips := resolveURLsToIPs(initialAddresses)
 
-	if err := m.sysOps.SetupRouting(ips, m.stateManager); err != nil {
+	if err := m.sysOps.SetupRouting(ips, m.stateManager, nbnet.AdvancedRouting()); err != nil {
 		return fmt.Errorf("setup routing: %w", err)
 	}
 
@@ -285,11 +289,15 @@ func (m *DefaultManager) Stop(stateManager *statemanager.Manager) {
 	}
 
 	if !nbnet.CustomRoutingDisabled() && !m.disableClientRoutes {
-		if err := m.sysOps.CleanupRouting(stateManager); err != nil {
+		if err := m.sysOps.CleanupRouting(stateManager, nbnet.AdvancedRouting()); err != nil {
 			log.Errorf("Error cleaning up routing: %v", err)
 		} else {
 			log.Info("Routing cleanup complete")
 		}
+
+		if runtime.GOOS == "windows" {
+			nbnet.SetVPNInterfaceName("")
+		}
 	}
 
 	m.mux.Lock()
@@ -368,7 +376,11 @@ func (m *DefaultManager) UpdateRoutes(
 
 	var merr *multierror.Error
 	if !m.disableClientRoutes {
-		filteredClientRoutes := m.routeSelector.FilterSelected(clientRoutes)
+
+		// Update route selector based on management server's isSelected status
+		m.updateRouteSelectorFromManagement(clientRoutes)
+
+		filteredClientRoutes := m.routeSelector.FilterSelectedExitNodes(clientRoutes)
 
 		if err := m.updateSystemRoutes(filteredClientRoutes); err != nil {
 			merr = multierror.Append(merr, fmt.Errorf("update system routes: %w", err))
@@ -430,7 +442,7 @@ func (m *DefaultManager) TriggerSelection(networks route.HAMap) {
 	m.mux.Lock()
 	defer m.mux.Unlock()
 
-	networks = m.routeSelector.FilterSelected(networks)
+	networks = m.routeSelector.FilterSelectedExitNodes(networks)
 
 	m.notifier.OnNewRoutes(networks)
 
@@ -583,3 +595,106 @@ func resolveURLsToIPs(urls []string) []net.IP {
 	}
 	return ips
 }
+
+// updateRouteSelectorFromManagement updates the route selector based on the isSelected status from the management server
+func (m *DefaultManager) updateRouteSelectorFromManagement(clientRoutes route.HAMap) {
+	exitNodeInfo := m.collectExitNodeInfo(clientRoutes)
+	if len(exitNodeInfo.allIDs) == 0 {
+		return
+	}
+
+	m.updateExitNodeSelections(exitNodeInfo)
+	m.logExitNodeUpdate(exitNodeInfo)
+}
+
+type exitNodeInfo struct {
+	allIDs               []route.NetID
+	selectedByManagement []route.NetID
+	userSelected         []route.NetID
+	userDeselected       []route.NetID
+}
+
+func (m *DefaultManager) collectExitNodeInfo(clientRoutes route.HAMap) exitNodeInfo {
+	var info exitNodeInfo
+
+	for haID, routes := range clientRoutes {
+		if !m.isExitNodeRoute(routes) {
+			continue
+		}
+
+		netID := haID.NetID()
+		info.allIDs = append(info.allIDs, netID)
+
+		if m.routeSelector.HasUserSelectionForRoute(netID) {
+			m.categorizeUserSelection(netID, &info)
+		} else {
+			m.checkManagementSelection(routes, netID, &info)
+		}
+	}
+
+	return info
+}
+
+func (m *DefaultManager) isExitNodeRoute(routes []*route.Route) bool {
+	return len(routes) > 0 && routes[0].Network.String() == vars.ExitNodeCIDR
+}
+
+func (m *DefaultManager) categorizeUserSelection(netID route.NetID, info *exitNodeInfo) {
+	if m.routeSelector.IsSelected(netID) {
+		info.userSelected = append(info.userSelected, netID)
+	} else {
+		info.userDeselected = append(info.userDeselected, netID)
+	}
+}
+
+func (m *DefaultManager) checkManagementSelection(routes []*route.Route, netID route.NetID, info *exitNodeInfo) {
+	for _, route := range routes {
+		if !route.SkipAutoApply {
+			info.selectedByManagement = append(info.selectedByManagement, netID)
+			break
+		}
+	}
+}
+
+func (m *DefaultManager) updateExitNodeSelections(info exitNodeInfo) {
+	routesToDeselect := m.getRoutesToDeselect(info.allIDs)
+	m.deselectExitNodes(routesToDeselect)
+	m.selectExitNodesByManagement(info.selectedByManagement, info.allIDs)
+}
+
+func (m *DefaultManager) getRoutesToDeselect(allIDs []route.NetID) []route.NetID {
+	var routesToDeselect []route.NetID
+	for _, netID := range allIDs {
+		if !m.routeSelector.HasUserSelectionForRoute(netID) {
+			routesToDeselect = append(routesToDeselect, netID)
+		}
+	}
+	return routesToDeselect
+}
+
+func (m *DefaultManager) deselectExitNodes(routesToDeselect []route.NetID) {
+	if len(routesToDeselect) == 0 {
+		return
+	}
+
+	err := m.routeSelector.DeselectRoutes(routesToDeselect, routesToDeselect)
+	if err != nil {
+		log.Warnf("Failed to deselect exit nodes: %v", err)
+	}
+}
+
+func (m *DefaultManager) selectExitNodesByManagement(selectedByManagement []route.NetID, allIDs []route.NetID) {
+	if len(selectedByManagement) == 0 {
+		return
+	}
+
+	err := m.routeSelector.SelectRoutes(selectedByManagement, true, allIDs)
+	if err != nil {
+		log.Warnf("Failed to select exit nodes: %v", err)
+	}
+}
+
+func (m *DefaultManager) logExitNodeUpdate(info exitNodeInfo) {
+	log.Debugf("Updated route selector: %d exit nodes available, %d selected by management, %d user-selected, %d user-deselected",
+		len(info.allIDs), len(info.selectedByManagement), len(info.userSelected), len(info.userDeselected))
+}

client/internal/routemanager/manager_test.go

@@ -190,14 +190,15 @@ func TestManagerUpdateRoutes(t *testing.T) {
 			name: "No Small Client Route Should Be Added",
 			inputRoutes: []*route.Route{
 				{
-					ID:          "a",
-					NetID:       "routeA",
-					Peer:        remotePeerKey1,
-					Network:     netip.MustParsePrefix("0.0.0.0/0"),
-					NetworkType: route.IPv4Network,
-					Metric:      9999,
-					Masquerade:  false,
-					Enabled:     true,
+					ID:            "a",
+					NetID:         "routeA",
+					Peer:          remotePeerKey1,
+					Network:       netip.MustParsePrefix("0.0.0.0/0"),
+					NetworkType:   route.IPv4Network,
+					Metric:        9999,
+					Masquerade:    false,
+					Enabled:       true,
+					SkipAutoApply: false,
 				},
 			},
 			inputSerial:                          1,