## Describe your changes
`NB_LAZY_CONN_INACTIVITY_THRESHOLD` was parsed with `strconv.Atoi`, i.e.
as a bare
integer number of minutes. The documentation, however, states it takes a
Go duration
(e.g. `30m`, `1h`). As a result any documented value such as `30m` or
`5m` failed to
parse and **silently fell back to the 15m default**, so the setting
appeared to have
no effect.
`inactivityThresholdEnv()` now parses the value with
`time.ParseDuration`, matching
the docs. A bare integer is still accepted as a number of minutes for
backwards
compatibility, and an unparseable value logs a warning and falls back to
the default.
Added `TestInactivityThresholdEnv` covering Go-duration values
(`30m`/`1h`/`90s`), the
bare-integer minutes fallback, and zero/negative/garbage inputs.
## Issue ticket number and link
N/A
## Describe your changes
Under lazy connections, when a routing peer goes idle its WireGuard peer
is torn down and re-created with a wake endpoint by
the activity listener, carrying only the overlay /32
(`peerCfg.AllowedIPs`). The routed subnet prefixes are dropped from
the device on the Connected→Idle transition.
They are meant to be restored by the route watcher, which reacts to the
peer's status change and calls `recalculateRoutes` →
`AddAllowedIP`. Two things prevent that from healing the peer:
- `AddAllowedIP` uses `update_only`, which is a silent no-op (no error)
when the peer does not exist. While the peer is
being torn down and re-armed with its wake endpoint, it is briefly
absent, so a re-add that lands in that window is lost.
- The allowed-IP refcounter only calls its add function on a prefix's
0→1 transition. The routed prefix stays referenced
across the idle cycle, so once the device entry is gone the refcounter
does not re-push it on its own, and nothing retries.
As a result, traffic to the routed subnet is black-holed while the peer
is idle. Because the wake endpoint only fires when a
packet matches the peer's AllowedIPs, a packet to the subnet is dropped
before reaching the wake endpoint, so it cannot
wake the peer. The peer only recovers when woken by other means (e.g. a
ping to its overlay IP).
## Approach
This change keeps the existing Connected→Idle transition as-is and
reconciles the AllowedIPs afterwards, avoiding any
additional locking on the transition path. The peer is torn down and
re-armed with its wake endpoint as today; the routed
prefixes are then re-applied from the route manager's allowed-IP
refcounter once the wake endpoint has been (re)armed.
A single add-only method, `ReconcilePeerAllowedIPs(peerKey)`, re-applies
every routed prefix currently tracked for the peer
in the refcounter (the authoritative store; it already covers static,
dynamic and dnsinterceptor routes). It runs whenever
the peer's wake endpoint is (re)created in the lazy manager — every
point where the activity listener builds it with the
overlay /32 only:
- **initial registration** (`AddPeer`, cold start): the route manager
may have already pushed the peer's routes before the
wake endpoint existed, so those `AddAllowedIP` calls no-op'd; the
reconcile installs them on the freshly created wake
endpoint.
- **the two paths into idle** (`DeactivatePeer` on a remote GOAWAY,
`onPeerInactivityTimedOut` on local inactivity): the
peer is torn down and re-armed, so the routed prefixes must be
re-applied.
In every case the routed prefixes end up on the wake endpoint, so
traffic to a routed subnet can wake the peer. Arming the
wake endpoint and reconciling are wrapped in a single
`armActivityListener` helper so the two always happen together.
New helper: `refcounter.Counter.KeysMatching(pred)` to enumerate a
peer's prefixes under the counter lock.
Note on scope: the reconcile restores what the refcounter tracks. All
routed AllowedIPs currently go through it, so this
covers the routed-prefix case; it does not attempt to reconcile
AllowedIPs installed outside the refcounter. The
Idle→Connected (wake) path does not need this: the peer is not removed
there (the listener close leaves it in place and only
the endpoint is updated), so a concurrent `AddAllowedIP` lands normally.
## Testing
Reproduced deterministically in a local dev setup (userspace client,
`NB_WG_KERNEL_DISABLED=true`, `B_LAZY_CONN_INACTIVITY_THRESHOLD=1`
inactivity threshold 1
min). A temporary 30s sleep in the tear-down → re-arm window widens the
race so the route watcher's async `AddAllowedIP`
reliably lands while the peer is absent and no-ops (the sleep is a test
aid, not part of the change):
- **without the reconcile:** after the peer goes idle, a ping to any
routed IP — both a pre-existing route and one added
during the window — black-holes; the peer never wakes.
- **with the reconcile:** the same ping wakes the peer and passes.
Added unit tests: `ReconcilePeerAllowedIPs` (re-applies all of a peer's
tracked prefixes, scoped to that peer) and
`refcounter.Counter.KeysMatching`.
Note: `netbird status -d` is not a reliable signal for this —
`AddPeerStateRoute` records the route regardless of whether
the underlying `AddAllowedIP` no-op'd, so it reflects the route
manager's intent rather than device state. The reliable
signal is functional (ping the subnet from idle).
## Checklist
- [x] Is it a bug fix
- [ ] Is a typo/documentation fix
- [ ] Is a feature enhancement
- [ ] It is a refactor
- [x] Created tests that fail without the change (unit tests for the
reconcile + `KeysMatching`)
## Documentation
- [x] Documentation is **not needed** for this change (internal client
behavior, no API / gRPC / CLI / flag change)
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<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **Bug Fixes**
* Routed IP assignments are automatically reconciled and restored
whenever a peer’s lazy wake endpoint is armed or re-armed.
* Routed allowed IPs are re-applied after inactivity transitions and
monitoring re-initialization.
* If reconciliation can’t be performed, the client safely skips it; if
reconciliation encounters issues, failures are logged without stopping
connection monitoring.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
## Describe your changes
Supersedes #6767 (same change, moved to an unprefixed branch; review
feedback from there is addressed here).
With lazy connections enabled, a peer is not dialed until on-demand
traffic arrives, so the first request to a peer resolved by name (e.g.
the agent-network reverse-proxy) races — or loses to — the WireGuard
handshake. Activation was previously reactive only: a data-path packet
or an inbound signal.
This adds a proactive, DNS-time trigger. When the local resolver answers
for an overlay name, it now warms the lazy connection to the peer(s) the
answer points at and waits briefly for one to connect before returning
the response — so by the time the client sends its first packet the
tunnel is already up.
- `dns/local`: new `PeerActivator` capability + `SetPeerActivator`
setter (mirrors the existing `PeerConnectivity`/`SetPeerConnectivity`
injection). `ServeDNS` warms on the pre-filter answer, so activating a
lazily-idle peer also lets it survive the disconnected-peer filter.
Warm-up is scoped to match-only (non-authoritative) zones — the
synthesized private-service zones and user-created zones — so plain
peer-name lookups in the account's authoritative peer zone never wake
idle peers. No-op when no activator is wired (lazy off) or the answer
carries no peer IPs. Budget is `NB_DNS_LAZY_WARMUP_TIMEOUT` (default 2s,
parsed once at construction, invalid values logged); on timeout the
answer is returned anyway (never SERVFAIL).
- The resolver-facing interfaces (`PeerActivator`, `PeerConnectivity`)
take `netip.Addr` instead of string IPs; record addresses are extracted
as `netip.Addr` (v4-mapped forms unmapped) and converted to string only
at the `peer.Status` boundary.
- `SetPeerActivator` is part of the `dns.Server` interface (no-op on the
mock), so the engine wires it without a type assertion.
- `client/internal`: a small engine-side adapter (`dnsPeerActivator`)
resolves answer IPs to peers via `Status.PeerStateByIP`, activates them
through `ConnMgr.ActivatePeer` (HA fan-out included), and polls
`PeerStateByIP` until one is connected. The activation dial is tied to
the engine's long-lived context so a handshake that outlasts the
per-query wait still completes in the background. `ConnMgr.ActivatePeer`
is safe for concurrent use (the lazy manager pointer is guarded by a
dedicated RWMutex and the manager is internally synchronized), so the
DNS path never contends with network-map processing on `syncMsgMux`.
Scope is overlay-only for free: the trigger lives in the local resolver,
which only answers for NetBird-managed names; public/upstream DNS is
unaffected. Already-connected peers short-circuit, so steady-state DNS
latency is unchanged.
## Issue ticket number and link
N/A — follow-up to the lazy-connection rollout; fixes the agent-network
cold-start observed in the e2e (proxy peer stuck disconnected until
traffic).
### Checklist
- [x] Is it a bug fix
- [ ] Is a typo/documentation fix
- [ ] Is a feature enhancement
- [ ] It is a refactor
- [x] Created tests that fail without the change (if possible)
- [x] This change does **not** modify the public API, gRPC protocols,
functionality behavior, CLI / service flags, or introduce a new feature
— **OR** I have discussed it with the NetBird team beforehand (link the
issue / Slack thread in the description). See
[CONTRIBUTING.md](https://github.com/netbirdio/netbird/blob/main/CONTRIBUTING.md#discuss-changes-with-the-netbird-team-first).
> By submitting this pull request, you confirm that you have read and
agree to the terms of the [Contributor License
Agreement](https://github.com/netbirdio/netbird/blob/main/CONTRIBUTOR_LICENSE_AGREEMENT.md).
## Documentation
Select exactly one:
- [ ] I added/updated documentation for this change
- [x] Documentation is **not needed** for this change (explain why)
Internal client behavior; the only knob is the optional
`NB_DNS_LAZY_WARMUP_TIMEOUT` tuning env var with a safe default.
### Docs PR URL (required if "docs added" is checked)
Paste the PR link from https://github.com/netbirdio/docs here:
https://github.com/netbirdio/docs/pull/__
## Tests
- `dns/local`: warm-up invokes the activator with the answer's peer
address in match-only zones; authoritative-zone answers never trigger
warm-up; no-activator path unchanged; no-answer queries don't invoke the
activator; `NB_DNS_LAZY_WARMUP_TIMEOUT` parsing
(valid/invalid/non-positive); `extractRecordAddr` unmaps v4-mapped
record data.
- `client/internal`: `dnsPeerActivator` skips
connected/unknown/conn-less peers with no wait, returns as soon as a
pending peer connects, and releases the DNS response at the budget when
the peer stays idle; `ConnMgr.ActivatePeer` races the manager lifecycle
cleanly under `-race`.
- Agent-network e2e green on this change (with lazy connections
enabled): https://github.com/netbirdio/netbird/actions/runs/29891467544
This PR introduces a new inactivity package responsible for monitoring peer activity and notifying when peers become inactive.
Introduces a new Signal message type to close the peer connection after the idle timeout is reached.
Periodically checks the last activity of registered peers via a Bind interface.
Notifies via a channel when peers exceed a configurable inactivity threshold.
Default settings
DefaultInactivityThreshold is set to 15 minutes, with a minimum allowed threshold of 1 minute.
Limitations
This inactivity check does not support kernel WireGuard integration. In kernel–user space communication, the user space side will always be responsible for closing the connection.
In the conn_mgr we must distinguish two contexts. One is relevant for lazy-manager, and one (engine context) is relevant for peer creation. If we use the incorrect context, then when we disable the lazy connection feature, we cancel the peer connections too, instead of just the lazy manager.
With the lazy connection feature, the peer will connect to target peers on-demand. The trigger can be any IP traffic.
This feature can be enabled with the NB_ENABLE_EXPERIMENTAL_LAZY_CONN environment variable.
When the engine receives a network map, it binds a free UDP port for every remote peer, and the system configures WireGuard endpoints for these ports. When traffic appears on a UDP socket, the system removes this listener and starts the peer connection procedure immediately.
Key changes
Fix slow netbird status -d command
Move from engine.go file to conn_mgr.go the peer connection related code
Refactor the iface interface usage and moved interface file next to the engine code
Add new command line flag and UI option to enable feature
The peer.Conn struct is reusable after it has been closed.
Change connection states
Connection states
Idle: The peer is not attempting to establish a connection. This typically means it's in a lazy state or the remote peer is expired.
Connecting: The peer is actively trying to establish a connection. This occurs when the peer has entered an active state and is continuously attempting to reach the remote peer.
Connected: A successful peer-to-peer connection has been established and communication is active.
