Merge branch 'main' into file-share

client/internal/acl/dispatch_test.go

@@ -0,0 +1,190 @@
+package acl
+
+import (
+	"net/netip"
+	"sync"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.uber.org/mock/gomock"
+
+	"github.com/netbirdio/netbird/client/firewall"
+	fwmgr "github.com/netbirdio/netbird/client/firewall/manager"
+	"github.com/netbirdio/netbird/client/iface"
+	"github.com/netbirdio/netbird/client/iface/wgaddr"
+	"github.com/netbirdio/netbird/client/internal/acl/mocks"
+	mgmProto "github.com/netbirdio/netbird/shared/management/proto"
+)
+
+// TestNetworkZeroPrefixIsRoute guards the route-vs-peer dispatch
+// invariant: the backends classify a rule as a peer rule purely by the
+// absence of a destination (neither prefix nor set). A default route
+// (0.0.0.0/0 or ::/0) is a valid prefix and must therefore classify as
+// a route, not collapse into the peer path.
+func TestNetworkZeroPrefixIsRoute(t *testing.T) {
+	for _, p := range []string{"0.0.0.0/0", "::/0", "10.0.0.0/8"} {
+		n := fwmgr.Network{Prefix: netip.MustParsePrefix(p)}
+		assert.True(t, n.IsPrefix(), "%s must report IsPrefix", p)
+		assert.True(t, n.IsPrefix() || n.IsSet(), "%s must classify as a route", p)
+	}
+
+	// A zero-value Network is the only peer-rule shape.
+	var empty fwmgr.Network
+	assert.False(t, empty.IsPrefix(), "zero Network must not be a prefix")
+	assert.False(t, empty.IsSet(), "zero Network must not be a set")
+}
+
+// TestDetermineDestinationAlwaysRoute verifies determineDestination
+// never yields an empty Network for a valid route rule: every branch
+// (static prefix, default route, dynamic with/without domains, with and
+// without a local resolver) produces a destination that classifies as a
+// route. If this regresses, a route rule would be dispatched down the
+// peer path, which matches on source only.
+func TestDetermineDestinationAlwaysRoute(t *testing.T) {
+	v4 := []netip.Prefix{netip.MustParsePrefix("10.0.0.0/24")}
+	v6 := []netip.Prefix{netip.MustParsePrefix("2001:db8::/48")}
+
+	cases := []struct {
+		name     string
+		rule     *mgmProto.RouteFirewallRule
+		resolver bool
+		sources  []netip.Prefix
+	}{
+		{"static prefix", &mgmProto.RouteFirewallRule{Destination: "192.168.0.0/16"}, false, v4},
+		{"static default route", &mgmProto.RouteFirewallRule{Destination: "0.0.0.0/0"}, false, v4},
+		{"dynamic with domains + resolver", &mgmProto.RouteFirewallRule{IsDynamic: true, Domains: []string{"example.com"}}, true, v4},
+		{"dynamic no domains + resolver (v4)", &mgmProto.RouteFirewallRule{IsDynamic: true}, true, v4},
+		{"dynamic no domains + resolver (v6)", &mgmProto.RouteFirewallRule{IsDynamic: true}, true, v6},
+		{"dynamic + no local resolver (v4)", &mgmProto.RouteFirewallRule{IsDynamic: true}, false, v4},
+		{"dynamic + no local resolver (v6)", &mgmProto.RouteFirewallRule{IsDynamic: true}, false, v6},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			dest, err := determineDestination(tc.rule, tc.resolver, tc.sources)
+			require.NoError(t, err)
+			assert.True(t, dest.IsPrefix() || dest.IsSet(),
+				"destination must classify as a route, got empty Network")
+		})
+	}
+}
+
+// countingFirewall wraps a real firewall.Manager and counts filter-rule
+// add/delete calls so a test can assert how many backing rules the acl
+// manager actually creates and tears down.
+type countingFirewall struct {
+	fwmgr.Manager
+	mu       sync.Mutex
+	addCalls int
+	dels     int
+	ruleIDs  map[fwmgr.RuleID]struct{}
+}
+
+// distinctRules returns the number of distinct backing rules the
+// backend produced. Because the backend dedups identical content,
+// repeated AddFilterRule calls for the same rule resolve to one id.
+func (f *countingFirewall) distinctRules() int {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	return len(f.ruleIDs)
+}
+
+func (f *countingFirewall) AddFilterRule(id []byte, sources []netip.Prefix, destination fwmgr.Network, proto fwmgr.Protocol, sPort, dPort *fwmgr.Port, action fwmgr.Action) (fwmgr.Rule, error) {
+	rule, err := f.Manager.AddFilterRule(id, sources, destination, proto, sPort, dPort, action)
+	if err == nil {
+		f.mu.Lock()
+		f.addCalls++
+		if f.ruleIDs == nil {
+			f.ruleIDs = make(map[fwmgr.RuleID]struct{})
+		}
+		if rule != nil {
+			f.ruleIDs[rule.ID()] = struct{}{}
+		}
+		f.mu.Unlock()
+	}
+	return rule, err
+}
+
+func (f *countingFirewall) DeleteFilterRule(r fwmgr.Rule) error {
+	err := f.Manager.DeleteFilterRule(r)
+	if err == nil {
+		f.mu.Lock()
+		f.dels++
+		delete(f.ruleIDs, r.ID())
+		f.mu.Unlock()
+	}
+	return err
+}
+
+func newCountingACL(t *testing.T) (*DefaultManager, *countingFirewall, func()) {
+	t.Helper()
+	t.Setenv("NB_WG_KERNEL_DISABLED", "true")
+	t.Setenv(firewall.EnvForceUserspaceFirewall, "true")
+
+	ctrl := gomock.NewController(t)
+	ifaceMock := mocks.NewMockIFaceMapper(ctrl)
+	ifaceMock.EXPECT().IsUserspaceBind().Return(true).AnyTimes()
+	ifaceMock.EXPECT().SetFilter(gomock.Any())
+	network := netip.MustParsePrefix("172.0.0.1/32")
+	ifaceMock.EXPECT().Name().Return("lo").AnyTimes()
+	ifaceMock.EXPECT().Address().Return(wgaddr.Address{IP: network.Addr(), Network: network}).AnyTimes()
+	ifaceMock.EXPECT().GetWGDevice().Return(nil).AnyTimes()
+
+	realFW, err := firewall.NewFirewall(ifaceMock, nil, flowLogger, false, iface.DefaultMTU)
+	require.NoError(t, err)
+
+	fw := &countingFirewall{Manager: realFW}
+	cleanup := func() {
+		require.NoError(t, realFW.Close(nil))
+		ctrl.Finish()
+	}
+	return NewDefaultManager(fw), fw, cleanup
+}
+
+// TestDuplicateContentPoliciesShareOneRule verifies the dedup contract
+// the backends rely on: two policies that authorize an identical flow
+// (same selector and sources) collapse to a single backing firewall
+// rule, and that rule survives until BOTH policies are gone. This is
+// why the backend can dedup on add without refcounting on delete: the
+// acl manager's pair key matches the backend's content key, so add and
+// delete stay balanced per content key across full-state reapplies.
+func TestDuplicateContentPoliciesShareOneRule(t *testing.T) {
+	acl, fw, cleanup := newCountingACL(t)
+	defer cleanup()
+
+	ruleA := &mgmProto.FirewallRule{
+		PolicyID:  []byte("policy-A"),
+		PeerIP:    "10.0.0.1", //nolint:staticcheck
+		Direction: mgmProto.RuleDirection_IN,
+		Action:    mgmProto.RuleAction_ACCEPT,
+		Protocol:  mgmProto.RuleProtocol_TCP,
+		Port:      "443",
+	}
+	ruleB := &mgmProto.FirewallRule{
+		PolicyID:  []byte("policy-B"),
+		PeerIP:    "10.0.0.1", //nolint:staticcheck
+		Direction: mgmProto.RuleDirection_IN,
+		Action:    mgmProto.RuleAction_ACCEPT,
+		Protocol:  mgmProto.RuleProtocol_TCP,
+		Port:      "443",
+	}
+
+	// Both policies present: identical content collapses to one rule.
+	acl.ApplyFiltering(&mgmProto.NetworkMap{FirewallRules: []*mgmProto.FirewallRule{ruleA, ruleB}, FirewallRulesIsEmpty: false}, false)
+	assert.Equal(t, 1, fw.distinctRules(), "identical-content policies must produce one backing rule")
+	assert.Equal(t, 1, len(acl.peerRulesPairs), "one content key, one pair")
+
+	// Drop policy A only: the shared rule is still authorized by B, so
+	// nothing is deleted.
+	acl.ApplyFiltering(&mgmProto.NetworkMap{FirewallRules: []*mgmProto.FirewallRule{ruleB}, FirewallRulesIsEmpty: false}, false)
+	assert.Equal(t, 1, fw.distinctRules(), "no new backing rule on reapply")
+	assert.Equal(t, 0, fw.dels, "rule must survive while any policy still authorizes it")
+	assert.Equal(t, 1, len(acl.peerRulesPairs))
+
+	// Drop policy B too: now the content key has no authorizer and the
+	// single backing rule is removed exactly once.
+	acl.ApplyFiltering(&mgmProto.NetworkMap{FirewallRules: nil, FirewallRulesIsEmpty: true}, false)
+	assert.Equal(t, 1, fw.dels, "rule removed once when last policy is gone")
+	assert.Equal(t, 0, len(acl.peerRulesPairs))
+}

client/internal/acl/grouping_test.go

@@ -0,0 +1,318 @@
+package acl
+
+import (
+	"errors"
+	"net/netip"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.uber.org/mock/gomock"
+
+	"github.com/netbirdio/netbird/client/firewall"
+	fwmgr "github.com/netbirdio/netbird/client/firewall/manager"
+	"github.com/netbirdio/netbird/client/iface"
+	"github.com/netbirdio/netbird/client/iface/wgaddr"
+	"github.com/netbirdio/netbird/client/internal/acl/mocks"
+	mgmProto "github.com/netbirdio/netbird/shared/management/proto"
+	"github.com/netbirdio/netbird/shared/netiputil"
+)
+
+// TestGroupPeerRulesPolicyIDSeparates verifies that two FirewallRules
+// with identical selectors but different PolicyIDs do NOT get merged
+// into one group, so each policy's sources merge under its own
+// attribution id. (Identical-content groups may still dedup to one
+// backing rule at the backend; see TestDuplicateContentPoliciesShareOneRule.)
+func TestGroupPeerRulesPolicyIDSeparates(t *testing.T) {
+	rules := []*mgmProto.FirewallRule{
+		{
+			PolicyID:  []byte("policy-A"),
+			PeerIP:    "10.0.0.1",
+			Direction: mgmProto.RuleDirection_IN,
+			Action:    mgmProto.RuleAction_ACCEPT,
+			Protocol:  mgmProto.RuleProtocol_TCP,
+			Port:      "443",
+		},
+		{
+			PolicyID:  []byte("policy-B"),
+			PeerIP:    "10.0.0.1",
+			Direction: mgmProto.RuleDirection_IN,
+			Action:    mgmProto.RuleAction_ACCEPT,
+			Protocol:  mgmProto.RuleProtocol_TCP,
+			Port:      "443",
+		},
+	}
+
+	groups, denyErr, err := groupPeerRules(rules)
+	require.NoError(t, denyErr)
+	require.NoError(t, err)
+	require.Len(t, groups, 2, "rules with different PolicyIDs must produce separate groups")
+}
+
+// TestGroupPeerRulesFamilySeparates verifies that v4 and v6 rules
+// belonging to the same policy don't merge.
+func TestGroupPeerRulesFamilySeparates(t *testing.T) {
+	rules := []*mgmProto.FirewallRule{
+		{
+			PolicyID:  []byte("policy-A"),
+			PeerIP:    "10.0.0.1",
+			Direction: mgmProto.RuleDirection_IN,
+			Action:    mgmProto.RuleAction_ACCEPT,
+			Protocol:  mgmProto.RuleProtocol_TCP,
+			Port:      "443",
+		},
+		{
+			PolicyID:  []byte("policy-A"),
+			PeerIP:    "2001:db8::1",
+			Direction: mgmProto.RuleDirection_IN,
+			Action:    mgmProto.RuleAction_ACCEPT,
+			Protocol:  mgmProto.RuleProtocol_TCP,
+			Port:      "443",
+		},
+	}
+
+	groups, denyErr, err := groupPeerRules(rules)
+	require.NoError(t, denyErr)
+	require.NoError(t, err)
+	require.Len(t, groups, 2, "rules of different families must produce separate groups")
+
+	var sawV4, sawV6 bool
+	for _, g := range groups {
+		require.Len(t, g.sources, 1)
+		if g.sources[0].Addr().Is4() {
+			sawV4 = true
+		}
+		if g.sources[0].Addr().Is6() {
+			sawV6 = true
+		}
+	}
+	assert.True(t, sawV4 && sawV6)
+}
+
+// TestGroupPeerRulesSplitsMixedFamilySingleRule verifies that a single
+// FirewallRule carrying both v4 and v6 source prefixes is split into one
+// group per family. Each backend keys a rule to a single family, so a
+// group whose sources span families would mismatch the other family's
+// sources. mgmt normally emits one rule per family; this guards against
+// a mixed-family rule slipping through.
+func TestGroupPeerRulesSplitsMixedFamilySingleRule(t *testing.T) {
+	srcs := [][]byte{
+		netiputil.EncodeAddr(netip.MustParseAddr("10.0.0.1")),
+		netiputil.EncodeAddr(netip.MustParseAddr("2001:db8::1")),
+		netiputil.EncodeAddr(netip.MustParseAddr("10.0.0.2")),
+		netiputil.EncodeAddr(netip.MustParseAddr("2001:db8::2")),
+	}
+	rules := []*mgmProto.FirewallRule{
+		{
+			PolicyID:       []byte("policy-A"),
+			SourcePrefixes: srcs,
+			Direction:      mgmProto.RuleDirection_IN,
+			Action:         mgmProto.RuleAction_ACCEPT,
+			Protocol:       mgmProto.RuleProtocol_TCP,
+			Port:           "443",
+		},
+	}
+
+	groups, denyErr, err := groupPeerRules(rules)
+	require.NoError(t, denyErr)
+	require.NoError(t, err)
+	require.Len(t, groups, 2, "mixed-family sources in one rule must split into two groups")
+
+	for _, g := range groups {
+		require.Len(t, g.sources, 2)
+		v6 := prefixIsV6(g.sources[0])
+		for _, s := range g.sources {
+			assert.Equal(t, v6, prefixIsV6(s), "every source in a group must share one family")
+		}
+	}
+}
+
+// TestGroupPeerRulesMergesSameSelector verifies that rules sharing
+// every distinguishing field (policy, family, direction, action,
+// proto, port) collapse into a single multi-source group.
+func TestGroupPeerRulesMergesSameSelector(t *testing.T) {
+	mk := func(peerIP string) *mgmProto.FirewallRule {
+		return &mgmProto.FirewallRule{
+			PolicyID:  []byte("policy-A"),
+			PeerIP:    peerIP, //nolint:staticcheck
+			Direction: mgmProto.RuleDirection_IN,
+			Action:    mgmProto.RuleAction_ACCEPT,
+			Protocol:  mgmProto.RuleProtocol_TCP,
+			Port:      "443",
+		}
+	}
+	rules := []*mgmProto.FirewallRule{mk("10.0.0.1"), mk("10.0.0.2"), mk("10.0.0.3")}
+
+	groups, denyErr, err := groupPeerRules(rules)
+	require.NoError(t, denyErr)
+	require.NoError(t, err)
+	require.Len(t, groups, 1)
+	require.Len(t, groups[0].sources, 3)
+}
+
+// TestGroupPeerRulesPortSeparates verifies that PortInfo is part of the
+// selector key: rules differing only in port must not merge, and a
+// single port must not merge with a range. A regression dropping the
+// port from the key would collapse rules for different ports into one.
+func TestGroupPeerRulesPortSeparates(t *testing.T) {
+	mkPort := func(peerIP string, port uint32) *mgmProto.FirewallRule {
+		return &mgmProto.FirewallRule{
+			PolicyID:  []byte("policy-A"),
+			PeerIP:    peerIP, //nolint:staticcheck
+			Direction: mgmProto.RuleDirection_IN,
+			Action:    mgmProto.RuleAction_ACCEPT,
+			Protocol:  mgmProto.RuleProtocol_TCP,
+			PortInfo:  &mgmProto.PortInfo{PortSelection: &mgmProto.PortInfo_Port{Port: port}},
+		}
+	}
+
+	groups, denyErr, err := groupPeerRules([]*mgmProto.FirewallRule{
+		mkPort("10.0.0.1", 80), mkPort("10.0.0.2", 80), mkPort("10.0.0.3", 443),
+	})
+	require.NoError(t, denyErr)
+	require.NoError(t, err)
+	require.Len(t, groups, 2, "rules on different ports must not merge")
+
+	rangeRule := &mgmProto.FirewallRule{
+		PolicyID:  []byte("policy-A"),
+		PeerIP:    "10.0.0.4", //nolint:staticcheck
+		Direction: mgmProto.RuleDirection_IN,
+		Action:    mgmProto.RuleAction_ACCEPT,
+		Protocol:  mgmProto.RuleProtocol_TCP,
+		PortInfo:  &mgmProto.PortInfo{PortSelection: &mgmProto.PortInfo_Range_{Range: &mgmProto.PortInfo_Range{Start: 80, End: 90}}},
+	}
+	groups, denyErr, err = groupPeerRules([]*mgmProto.FirewallRule{mkPort("10.0.0.1", 80), rangeRule})
+	require.NoError(t, denyErr)
+	require.NoError(t, err)
+	require.Len(t, groups, 2, "a single port and a range must not merge")
+}
+
+// TestGroupPeerRulesUsesSourcePrefixesWhenPresent verifies that the
+// new sourcePrefixes wire field is consumed and produces a
+// multi-source group in one shot (no client-side merging needed).
+func TestGroupPeerRulesUsesSourcePrefixesWhenPresent(t *testing.T) {
+	srcs := [][]byte{
+		netiputil.EncodeAddr(netip.MustParseAddr("10.0.0.1")),
+		netiputil.EncodeAddr(netip.MustParseAddr("10.0.0.2")),
+		netiputil.EncodeAddr(netip.MustParseAddr("10.0.0.3")),
+	}
+	rules := []*mgmProto.FirewallRule{
+		{
+			PolicyID:       []byte("policy-A"),
+			SourcePrefixes: srcs,
+			Direction:      mgmProto.RuleDirection_IN,
+			Action:         mgmProto.RuleAction_ACCEPT,
+			Protocol:       mgmProto.RuleProtocol_TCP,
+			Port:           "443",
+		},
+	}
+
+	groups, denyErr, err := groupPeerRules(rules)
+	require.NoError(t, denyErr)
+	require.NoError(t, err)
+	require.Len(t, groups, 1)
+	require.Len(t, groups[0].sources, 3)
+}
+
+// TestGroupPeerRulesActionSeparates verifies the obvious: accept
+// and drop rules with the same selector don't merge.
+func TestGroupPeerRulesActionSeparates(t *testing.T) {
+	rules := []*mgmProto.FirewallRule{
+		{
+			PolicyID:  []byte("policy-A"),
+			PeerIP:    "10.0.0.1",
+			Direction: mgmProto.RuleDirection_IN,
+			Action:    mgmProto.RuleAction_ACCEPT,
+			Protocol:  mgmProto.RuleProtocol_TCP,
+			Port:      "443",
+		},
+		{
+			PolicyID:  []byte("policy-A"),
+			PeerIP:    "10.0.0.1",
+			Direction: mgmProto.RuleDirection_IN,
+			Action:    mgmProto.RuleAction_DROP,
+			Protocol:  mgmProto.RuleProtocol_TCP,
+			Port:      "443",
+		},
+	}
+
+	groups, denyErr, err := groupPeerRules(rules)
+	require.NoError(t, denyErr)
+	require.NoError(t, err)
+	require.Len(t, groups, 2)
+}
+
+// failingDeleteFirewall wraps a real firewall.Manager and forces the
+// next N DeleteFilterRule calls to fail. Used to verify that the acl
+// manager retains rules whose deletion was rejected by the backend,
+// so they get retried on the next ApplyFiltering pass instead of
+// becoming orphans.
+type failingDeleteFirewall struct {
+	fwmgr.Manager
+	failCount int
+}
+
+func (f *failingDeleteFirewall) DeleteFilterRule(r fwmgr.Rule) error {
+	if f.failCount > 0 {
+		f.failCount--
+		return errors.New("simulated delete failure")
+	}
+	return f.Manager.DeleteFilterRule(r)
+}
+
+// TestApplyFilteringRetainsRulesOnDeleteFailure verifies that a
+// transient DeleteFilterRule error doesn't make the acl manager
+// forget about a rule. The rule must remain in peerRulesPairs so the
+// next ApplyFiltering pass attempts the delete again.
+func TestApplyFilteringRetainsRulesOnDeleteFailure(t *testing.T) {
+	t.Setenv("NB_WG_KERNEL_DISABLED", "true")
+	t.Setenv(firewall.EnvForceUserspaceFirewall, "true")
+
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+
+	ifaceMock := mocks.NewMockIFaceMapper(ctrl)
+	ifaceMock.EXPECT().IsUserspaceBind().Return(true).AnyTimes()
+	ifaceMock.EXPECT().SetFilter(gomock.Any())
+	network := netip.MustParsePrefix("172.0.0.1/32")
+	ifaceMock.EXPECT().Name().Return("lo").AnyTimes()
+	ifaceMock.EXPECT().Address().Return(wgaddr.Address{IP: network.Addr(), Network: network}).AnyTimes()
+	ifaceMock.EXPECT().GetWGDevice().Return(nil).AnyTimes()
+
+	realFW, err := firewall.NewFirewall(ifaceMock, nil, flowLogger, false, iface.DefaultMTU)
+	require.NoError(t, err)
+	defer func() { require.NoError(t, realFW.Close(nil)) }()
+
+	fw := &failingDeleteFirewall{Manager: realFW}
+	acl := NewDefaultManager(fw)
+
+	// First pass: install a rule.
+	netmap1 := &mgmProto.NetworkMap{
+		FirewallRules: []*mgmProto.FirewallRule{
+			{
+				PolicyID:  []byte("policy-A"),
+				PeerIP:    "10.0.0.1",
+				Direction: mgmProto.RuleDirection_IN,
+				Action:    mgmProto.RuleAction_DROP,
+				Protocol:  mgmProto.RuleProtocol_TCP,
+				Port:      "22",
+			},
+		},
+		FirewallRulesIsEmpty: false,
+	}
+	acl.ApplyFiltering(netmap1, false)
+	require.Equal(t, 1, len(acl.peerRulesPairs), "rule should be installed")
+
+	// Second pass: remove the rule from the map. The backend will
+	// fail the delete; the acl manager must retain the rule.
+	fw.failCount = 1
+	netmap2 := &mgmProto.NetworkMap{FirewallRules: nil, FirewallRulesIsEmpty: true}
+	acl.ApplyFiltering(netmap2, false)
+	require.Equal(t, 1, len(acl.peerRulesPairs),
+		"rule must be retained when DeleteFilterRule fails so it gets retried")
+
+	// Third pass: same map, backend no longer fails. The rule
+	// should now succeed in being removed.
+	acl.ApplyFiltering(netmap2, false)
+	require.Equal(t, 0, len(acl.peerRulesPairs), "retry should succeed")
+}

client/internal/acl/id/id.go

@@ -5,18 +5,18 @@ import (
 	"encoding/hex"
 	"fmt"
 	"net/netip"
+	"slices"
 	"strconv"
 
 	"github.com/netbirdio/netbird/client/firewall/manager"
 )
 
-type RuleID string
+// RuleID aliases manager.RuleID so existing nbid.RuleID references
+// keep working while the canonical type lives in the firewall package.
+type RuleID = manager.RuleID
 
-func (r RuleID) ID() string {
-	return string(r)
-}
-
-func GenerateRouteRuleKey(
+// GenerateRuleID returns a deterministic content hash identifying a filter rule.
+func GenerateRuleID(
 	sources []netip.Prefix,
 	destination manager.Network,
 	proto manager.Protocol,
@@ -24,6 +24,7 @@ func GenerateRouteRuleKey(
 	dPort *manager.Port,
 	action manager.Action,
 ) RuleID {
+	sources = slices.Clone(sources)
 	manager.SortPrefixes(sources)
 
 	h := sha256.New()

client/internal/acl/legacy_fallback_test.go

@@ -0,0 +1,75 @@
+package acl
+
+import (
+	"net/netip"
+	"sync"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.uber.org/mock/gomock"
+
+	"github.com/netbirdio/netbird/client/firewall"
+	fwmgr "github.com/netbirdio/netbird/client/firewall/manager"
+	"github.com/netbirdio/netbird/client/iface"
+	"github.com/netbirdio/netbird/client/iface/wgaddr"
+	"github.com/netbirdio/netbird/client/internal/acl/mocks"
+	mgmProto "github.com/netbirdio/netbird/shared/management/proto"
+)
+
+// sourcesRecordingFirewall wraps a real firewall.Manager and records
+// the source prefixes of every AddFilterRule call.
+type sourcesRecordingFirewall struct {
+	fwmgr.Manager
+	mu      sync.Mutex
+	sources [][]netip.Prefix
+}
+
+func (f *sourcesRecordingFirewall) AddFilterRule(id []byte, sources []netip.Prefix, destination fwmgr.Network, proto fwmgr.Protocol, sPort, dPort *fwmgr.Port, action fwmgr.Action) (fwmgr.Rule, error) {
+	f.mu.Lock()
+	f.sources = append(f.sources, sources)
+	f.mu.Unlock()
+	return f.Manager.AddFilterRule(id, sources, destination, proto, sPort, dPort, action)
+}
+
+// TestLegacyManagementFallbackUsesMatchAnySources verifies the
+// allow-all fallback for old management servers (empty FirewallRules
+// without the FirewallRulesIsEmpty flag) reaches the firewall as /0
+// match-any sources. The fallback rule carries PeerIP 0.0.0.0; if that
+// were converted to a host prefix (0.0.0.0/32) it would match nothing
+// and all peer traffic would be dropped.
+func TestLegacyManagementFallbackUsesMatchAnySources(t *testing.T) {
+	t.Setenv("NB_WG_KERNEL_DISABLED", "true")
+	t.Setenv(firewall.EnvForceUserspaceFirewall, "true")
+
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+
+	ifaceMock := mocks.NewMockIFaceMapper(ctrl)
+	ifaceMock.EXPECT().IsUserspaceBind().Return(true).AnyTimes()
+	ifaceMock.EXPECT().SetFilter(gomock.Any())
+	network := netip.MustParsePrefix("172.0.0.1/32")
+	ifaceMock.EXPECT().Name().Return("lo").AnyTimes()
+	ifaceMock.EXPECT().Address().Return(wgaddr.Address{IP: network.Addr(), Network: network}).AnyTimes()
+	ifaceMock.EXPECT().GetWGDevice().Return(nil).AnyTimes()
+
+	realFW, err := firewall.NewFirewall(ifaceMock, nil, flowLogger, false, iface.DefaultMTU)
+	require.NoError(t, err)
+	defer func() { require.NoError(t, realFW.Close(nil)) }()
+
+	fw := &sourcesRecordingFirewall{Manager: realFW}
+	acl := NewDefaultManager(fw)
+
+	// Old management: no rules and no FirewallRulesIsEmpty flag.
+	acl.ApplyFiltering(&mgmProto.NetworkMap{FirewallRules: nil, FirewallRulesIsEmpty: false}, false)
+
+	fw.mu.Lock()
+	defer fw.mu.Unlock()
+	require.NotEmpty(t, fw.sources, "legacy fallback must install at least one allow-all rule")
+	for _, sources := range fw.sources {
+		require.NotEmpty(t, sources)
+		for _, p := range sources {
+			assert.Equal(t, 0, p.Bits(), "legacy fallback source %s must be a /0 match-any prefix", p)
+		}
+	}
+}

client/internal/acl/manager.go

@@ -1,8 +1,6 @@
 package acl
 
 import (
-	"crypto/md5"
-	"encoding/hex"
 	"errors"
 	"fmt"
 	"net/netip"
@@ -24,6 +22,10 @@ import (
 
 var ErrSourceRangesEmpty = errors.New("sources range is empty")
 
+// ErrNoRuleReturned is returned when the firewall backend reports success
+// from AddFilterRule but yields no rule to track.
+var ErrNoRuleReturned = errors.New("backend returned no rule")
+
 // Manager is a ACL rules manager
 type Manager interface {
 	ApplyFiltering(networkMap *mgmProto.NetworkMap, dnsRouteFeatureFlag bool)
@@ -32,19 +34,48 @@ type Manager interface {
 // DefaultManager uses firewall manager to handle
 type DefaultManager struct {
 	firewall           firewall.Manager
-	ipsetCounter       int
 	peerRulesPairs     map[id.RuleID][]firewall.Rule
-	routeRules         map[id.RuleID]struct{}
+	routeRules         map[id.RuleID]firewall.Rule
 	previousConfigHash uint64
 	hasAppliedConfig   bool
 	mutex              sync.Mutex
 }
 
+// peerRuleGroup collapses a set of single-source FirewallRules sharing
+// the same selector into one multi-source rule to push to the backend.
+type peerRuleGroup struct {
+	direction mgmProto.RuleDirection
+	action    mgmProto.RuleAction
+	protocol  mgmProto.RuleProtocol
+	port      *mgmProto.PortInfo
+	// legacyPort is used only when PortInfo is empty (old management).
+	legacyPort string
+	policyID   []byte
+	sources    []netip.Prefix
+}
+
+// peerRuleKey is the comparable selector that decides which single-source
+// rules merge into one group. Rules with an equal key collapse into one
+// multi-source backend rule. PortInfo is flattened into its scalar fields
+// so the key compares by value; policyID keeps policies separate so two
+// policies authorizing different peers don't merge under one attribution.
+type peerRuleKey struct {
+	v6         bool
+	policyID   string
+	direction  mgmProto.RuleDirection
+	action     mgmProto.RuleAction
+	protocol   mgmProto.RuleProtocol
+	legacyPort string
+	port       uint16
+	rangeStart uint16
+	rangeEnd   uint16
+}
+
 func NewDefaultManager(fm firewall.Manager) *DefaultManager {
 	return &DefaultManager{
 		firewall:       fm,
 		peerRulesPairs: make(map[id.RuleID][]firewall.Rule),
-		routeRules:     make(map[id.RuleID]struct{}),
+		routeRules:     make(map[id.RuleID]firewall.Rule),
 	}
 }
 
@@ -88,11 +119,14 @@ func (d *DefaultManager) ApplyFiltering(networkMap *mgmProto.NetworkMap, dnsRout
 			time.Since(start), total)
 	}()
 
-	d.applyPeerACLs(networkMap)
+	peerErr := d.applyPeerACLs(networkMap)
+	if peerErr != nil {
+		log.Errorf("apply peer ACLs: %v", peerErr)
+	}
 
 	routeErr := d.applyRouteACLs(networkMap.RoutesFirewallRules, dnsRouteFeatureFlag)
 	if routeErr != nil {
-		log.Errorf("Failed to apply route ACLs: %v", routeErr)
+		log.Errorf("apply route ACLs: %v", routeErr)
 	}
 
 	flushErr := d.firewall.Flush()
@@ -104,7 +138,7 @@ func (d *DefaultManager) ApplyFiltering(networkMap *mgmProto.NetworkMap, dnsRout
 	// If applying or flushing failed, leave the previous hash untouched so the
 	// next (possibly identical) update is not skipped and gets a chance to
 	// reconcile the firewall state.
-	if err == nil && routeErr == nil && flushErr == nil {
+	if err == nil && peerErr == nil && routeErr == nil && flushErr == nil {
 		d.previousConfigHash = hash
 		d.hasAppliedConfig = true
 	} else {
@@ -135,7 +169,7 @@ func (d *DefaultManager) firewallConfigHash(networkMap *mgmProto.NetworkMap, dns
 	})
 }
 
-func (d *DefaultManager) applyPeerACLs(networkMap *mgmProto.NetworkMap) {
+func (d *DefaultManager) applyPeerACLs(networkMap *mgmProto.NetworkMap) error {
 	rules := networkMap.FirewallRules
 
 	// if we got empty rules list but management not set networkMap.FirewallRulesIsEmpty flag
@@ -158,59 +192,167 @@ func (d *DefaultManager) applyPeerACLs(networkMap *mgmProto.NetworkMap) {
 		)
 	}
 
-	newRulePairs := make(map[id.RuleID][]firewall.Rule)
-	ipsetByRuleSelectors := make(map[string]string)
+	// Group incoming single-source rules from management by their
+	// (direction, action, proto, port) selector and merge sources.
+	// One call to the firewall backend per merged rule.
+	// A deny we cannot decode would leave its traffic unblocked, so skip
+	// the whole pass and keep existing rules until the next sync.
+	groups, denyErr, err := groupPeerRules(rules)
+	if denyErr != nil {
+		return fmt.Errorf("decode deny rule sources: %w", denyErr)
+	}
 
-	// TODO: deny rules should be fatal: if a deny rule fails to apply, we must
-	// roll back all allow rules to avoid a fail-open where allowed traffic bypasses
-	// the missing deny. Currently we accumulate errors and continue.
+	newRulePairs := make(map[id.RuleID][]firewall.Rule)
 	var merr *multierror.Error
-	for _, r := range rules {
-		// if this rule is member of rule selection with more than DefaultIPsCountForSet
-		// it's IP address can be used in the ipset for firewall manager which supports it
-		selector := d.getRuleGroupingSelector(r)
-		ipsetName, ok := ipsetByRuleSelectors[selector]
-		if !ok {
-			d.ipsetCounter++
-			ipsetName = fmt.Sprintf("nb%07d", d.ipsetCounter)
-			ipsetByRuleSelectors[selector] = ipsetName
-		}
-		pairID, rulePair, err := d.protoRuleToFirewallRule(r, ipsetName)
-		if err != nil {
-			merr = multierror.Append(merr, fmt.Errorf("apply firewall rule: %w", err))
+	if err != nil {
+		merr = multierror.Append(merr, err)
+	}
+
+	// Apply denies first. A deny that fails to install is a security
+	// failure (fail-open), so if any deny errors we roll back the
+	// denies we already installed in this pass and bail out without
+	// installing any accept. Pre-existing rules stay untouched until
+	// the next successful pass clears them.
+	denies, accepts := splitDenyAccept(groups)
+	if err := d.installPeerGroups(denies, newRulePairs, true); err != nil {
+		return fmt.Errorf("install deny rules: %w", err)
+	}
+
+	if err := d.installPeerGroups(accepts, newRulePairs, false); err != nil {
+		merr = multierror.Append(merr, err)
+	}
+
+	// Tear down rules that disappeared from the networkmap. Any rule
+	// the backend refuses to delete stays in our tracking so it gets
+	// retried on the next ApplyFiltering. Otherwise a transient
+	// delete failure would leak the rule in the firewall until the
+	// process exits.
+	for pairID, rules := range d.peerRulesPairs {
+		if _, ok := newRulePairs[pairID]; ok {
 			continue
 		}
-		if len(rulePair) > 0 {
-			d.peerRulesPairs[pairID] = rulePair
-			newRulePairs[pairID] = rulePair
-		}
-	}
-
-	if merr != nil {
-		log.Errorf("failed to apply %d peer ACL rule(s): %v", merr.Len(), nberrors.FormatErrorOrNil(merr))
-	}
-
-	for pairID, rules := range d.peerRulesPairs {
-		if _, ok := newRulePairs[pairID]; !ok {
-			for _, rule := range rules {
-				if err := d.firewall.DeletePeerRule(rule); err != nil {
-					log.Errorf("failed to delete peer firewall rule: %v", err)
-					continue
-				}
+		var remaining []firewall.Rule
+		for _, rule := range rules {
+			if err := d.firewall.DeleteFilterRule(rule); err != nil {
+				merr = multierror.Append(merr, fmt.Errorf("delete peer rule, will retry: %w", err))
+				remaining = append(remaining, rule)
 			}
-			delete(d.peerRulesPairs, pairID)
+		}
+		if len(remaining) > 0 {
+			newRulePairs[pairID] = remaining
 		}
 	}
 	d.peerRulesPairs = newRulePairs
+
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+// installPeerGroups applies each group and records the resulting rule
+// pairs in newRulePairs. With atomic set (deny rules), a single failure
+// rolls back every rule installed in this call and returns, leaving the
+// firewall exactly as before: denies are fail-closed and must be applied
+// all-or-nothing. With atomic unset (accept rules), failures are
+// accumulated and the remaining groups still install, so one malformed
+// allow cannot drop every other legitimate allow in the pass.
+func (d *DefaultManager) installPeerGroups(groups []*peerRuleGroup, newRulePairs map[id.RuleID][]firewall.Rule, atomic bool) error {
+	var freshlyInstalled []id.RuleID
+	var merr *multierror.Error
+	for _, g := range groups {
+		pairID, rulePair, err := d.applyPeerGroup(g)
+		if err != nil {
+			if atomic {
+				d.rollbackInstalled(freshlyInstalled)
+				return fmt.Errorf("apply firewall rule: %w", err)
+			}
+			merr = multierror.Append(merr, fmt.Errorf("apply firewall rule: %w", err))
+			continue
+		}
+		if len(rulePair) == 0 {
+			continue
+		}
+		if _, existed := d.peerRulesPairs[pairID]; !existed {
+			freshlyInstalled = append(freshlyInstalled, pairID)
+		}
+		d.peerRulesPairs[pairID] = rulePair
+		newRulePairs[pairID] = rulePair
+	}
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+func (d *DefaultManager) rollbackInstalled(pairIDs []id.RuleID) {
+	var merr *multierror.Error
+	for _, pairID := range pairIDs {
+		// Keep any rule the backend refuses to delete tracked so it is
+		// retried on the next ApplyFiltering instead of leaking in the
+		// firewall with no tracking left to remove it.
+		var remaining []firewall.Rule
+		for _, rule := range d.peerRulesPairs[pairID] {
+			if err := d.firewall.DeleteFilterRule(rule); err != nil {
+				merr = multierror.Append(merr, fmt.Errorf("rule %s: %w", pairID, err))
+				remaining = append(remaining, rule)
+			}
+		}
+		if len(remaining) > 0 {
+			d.peerRulesPairs[pairID] = remaining
+		} else {
+			delete(d.peerRulesPairs, pairID)
+		}
+	}
+	if err := nberrors.FormatErrorOrNil(merr); err != nil {
+		log.Errorf("rollback peer rules: %v", err)
+	}
+}
+
+func (d *DefaultManager) applyPeerGroup(g *peerRuleGroup) (id.RuleID, []firewall.Rule, error) {
+	protocol, err := ConvertToFirewallProtocol(g.protocol)
+	if err != nil {
+		return "", nil, fmt.Errorf("skipping firewall rule: %w", err)
+	}
+	action, err := convertFirewallAction(g.action)
+	if err != nil {
+		return "", nil, fmt.Errorf("skipping firewall rule: %w", err)
+	}
+	port, err := resolveGroupPort(g)
+	if err != nil {
+		return "", nil, err
+	}
+
+	var fwRule firewall.Rule
+	switch g.direction {
+	case mgmProto.RuleDirection_IN:
+		fwRule, err = d.firewall.AddFilterRule(g.policyID, g.sources, firewall.Network{}, protocol, nil, port, action)
+	case mgmProto.RuleDirection_OUT:
+		if d.firewall.IsStateful() {
+			return "", nil, nil
+		}
+		if shouldSkipInvertedRule(protocol, port) {
+			return "", nil, nil
+		}
+		fwRule, err = d.firewall.AddFilterRule(g.policyID, g.sources, firewall.Network{}, protocol, port, nil, action)
+	default:
+		return "", nil, errors.New("invalid direction")
+	}
+
+	if err != nil {
+		return "", nil, fmt.Errorf("add firewall rule: %w", err)
+	}
+	if fwRule == nil {
+		return "", nil, fmt.Errorf("add firewall rule: %w", ErrNoRuleReturned)
+	}
+
+	// Derive the pair id from the backend rule, like the route path:
+	// the backend dedups identical content, so two policies authorizing
+	// the same flow resolve to the same id and a single backing rule.
+	return fwRule.ID(), []firewall.Rule{fwRule}, nil
 }
 
 func (d *DefaultManager) applyRouteACLs(rules []*mgmProto.RouteFirewallRule, dynamicResolver bool) error {
-	newRouteRules := make(map[id.RuleID]struct{}, len(rules))
+	newRouteRules := make(map[id.RuleID]firewall.Rule, len(rules))
 	var merr *multierror.Error
 
-	// Apply new rules - firewall manager will return existing rule ID if already present
+	// Apply new rules - firewall manager will return the existing rule if already present
 	for _, rule := range rules {
-		id, err := d.applyRouteACL(rule, dynamicResolver)
+		addedRule, err := d.applyRouteACL(rule, dynamicResolver)
 		if err != nil {
 			if errors.Is(err, ErrSourceRangesEmpty) {
 				log.Debugf("skipping empty sources rule with destination %s: %v", rule.Destination, err)
@@ -219,16 +361,18 @@ func (d *DefaultManager) applyRouteACLs(rules []*mgmProto.RouteFirewallRule, dyn
 			}
 			continue
 		}
-		newRouteRules[id] = struct{}{}
+		newRouteRules[addedRule.ID()] = addedRule
 	}
 
-	// Clean up old firewall rules
-	for id := range d.routeRules {
-		if _, exists := newRouteRules[id]; !exists {
-			if err := d.firewall.DeleteRouteRule(id); err != nil {
-				merr = multierror.Append(merr, fmt.Errorf("delete route rule: %w", err))
-			}
-			// implicitly deleted from the map
+	// Tear down old route rules; retain ones the backend refused so a
+	// transient failure doesn't leave orphaned rules in the firewall.
+	for ruleID, rule := range d.routeRules {
+		if _, exists := newRouteRules[ruleID]; exists {
+			continue
+		}
+		if err := d.firewall.DeleteFilterRule(rule); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("delete route rule, will retry: %w", err))
+			newRouteRules[ruleID] = rule
 		}
 	}
 
@@ -236,102 +380,202 @@ func (d *DefaultManager) applyRouteACLs(rules []*mgmProto.RouteFirewallRule, dyn
 	return nberrors.FormatErrorOrNil(merr)
 }
 
-func (d *DefaultManager) applyRouteACL(rule *mgmProto.RouteFirewallRule, dynamicResolver bool) (id.RuleID, error) {
+func (d *DefaultManager) applyRouteACL(rule *mgmProto.RouteFirewallRule, dynamicResolver bool) (firewall.Rule, error) {
 	if len(rule.SourceRanges) == 0 {
-		return "", ErrSourceRangesEmpty
+		return nil, ErrSourceRangesEmpty
 	}
 
 	var sources []netip.Prefix
 	for _, sourceRange := range rule.SourceRanges {
 		source, err := netip.ParsePrefix(sourceRange)
 		if err != nil {
-			return "", fmt.Errorf("parse source range: %w", err)
+			return nil, fmt.Errorf("parse source range: %w", err)
 		}
-		sources = append(sources, source)
+		sources = append(sources, firewall.UnmapPrefix(source))
 	}
 
 	destination, err := determineDestination(rule, dynamicResolver, sources)
 	if err != nil {
-		return "", fmt.Errorf("determine destination: %w", err)
+		return nil, fmt.Errorf("determine destination: %w", err)
 	}
 
-	protocol, err := convertToFirewallProtocol(rule.Protocol)
+	protocol, err := ConvertToFirewallProtocol(rule.Protocol)
 	if err != nil {
-		return "", fmt.Errorf("invalid protocol: %w", err)
+		return nil, fmt.Errorf("invalid protocol: %w", err)
 	}
 
 	action, err := convertFirewallAction(rule.Action)
 	if err != nil {
-		return "", fmt.Errorf("invalid action: %w", err)
+		return nil, fmt.Errorf("invalid action: %w", err)
 	}
 
 	dPorts := convertPortInfo(rule.PortInfo)
 
-	addedRule, err := d.firewall.AddRouteFiltering(rule.PolicyID, sources, destination, protocol, nil, dPorts, action)
+	addedRule, err := d.firewall.AddFilterRule(rule.PolicyID, sources, destination, protocol, nil, dPorts, action)
 	if err != nil {
-		return "", fmt.Errorf("add route rule: %w", err)
+		return nil, fmt.Errorf("add route rule: %w", err)
+	}
+	if addedRule == nil {
+		return nil, fmt.Errorf("add route rule: %w", ErrNoRuleReturned)
 	}
 
-	return id.RuleID(addedRule.ID()), nil
+	return addedRule, nil
 }
 
-func (d *DefaultManager) protoRuleToFirewallRule(
-	r *mgmProto.FirewallRule,
-	ipsetName string,
-) (id.RuleID, []firewall.Rule, error) {
-	ip, err := extractRuleIP(r)
-	if err != nil {
-		return "", nil, err
+// splitDenyAccept partitions groups by action so denies can be
+// applied before accepts. Order within each bucket is preserved.
+func splitDenyAccept(groups []*peerRuleGroup) (denies, accepts []*peerRuleGroup) {
+	for _, g := range groups {
+		if g.action == mgmProto.RuleAction_DROP {
+			denies = append(denies, g)
+		} else {
+			accepts = append(accepts, g)
+		}
+	}
+	return denies, accepts
+}
+
+// groupPeerRules merges single-source rules sharing a selector into
+// multi-source groups. It splits source-decode failures by action:
+// denyErr is non-nil when a deny rule could not be decoded, which is a
+// fail-open risk the caller must treat as fatal for the pass; err
+// carries the tolerable accept-rule failures the caller can log and
+// continue past.
+func groupPeerRules(rules []*mgmProto.FirewallRule) (groups []*peerRuleGroup, denyErr error, err error) {
+	var denyMerr, acceptMerr *multierror.Error
+	byKey := make(map[peerRuleKey]*peerRuleGroup)
+	order := make([]peerRuleKey, 0)
+
+	for _, r := range rules {
+		srcs, decErr := extractRuleSources(r)
+		if decErr != nil {
+			if r.Action == mgmProto.RuleAction_DROP {
+				denyMerr = multierror.Append(denyMerr, decErr)
+			} else {
+				acceptMerr = multierror.Append(acceptMerr, decErr)
+			}
+			continue
+		}
+		// A single FirewallRule normally carries one address family, but
+		// split by family defensively: each backend keys a rule to one
+		// family and would mismatch sources of the other, so a group's
+		// sources must never span families.
+		v4, v6 := splitPrefixesByFamily(srcs)
+		for _, sub := range []struct {
+			isV6    bool
+			sources []netip.Prefix
+		}{{false, v4}, {true, v6}} {
+			if len(sub.sources) == 0 {
+				continue
+			}
+			key := ruleGroupKey(r, sub.isV6)
+			g, ok := byKey[key]
+			if !ok {
+				g = &peerRuleGroup{
+					direction:  r.Direction,
+					action:     r.Action,
+					protocol:   r.Protocol,
+					port:       r.PortInfo,
+					legacyPort: r.Port,
+					policyID:   r.PolicyID,
+				}
+				byKey[key] = g
+				order = append(order, key)
+			}
+			g.sources = append(g.sources, sub.sources...)
+		}
 	}
 
-	protocol, err := convertToFirewallProtocol(r.Protocol)
-	if err != nil {
-		return "", nil, fmt.Errorf("skipping firewall rule: %s", err)
+	out := make([]*peerRuleGroup, 0, len(order))
+	for _, k := range order {
+		out = append(out, byKey[k])
+	}
+	return out, nberrors.FormatErrorOrNil(denyMerr), nberrors.FormatErrorOrNil(acceptMerr)
+}
+
+func prefixIsV6(p netip.Prefix) bool {
+	return p.Addr().Is6() && !p.Addr().Is4In6()
+}
+
+// splitPrefixesByFamily partitions prefixes into IPv4 and IPv6 groups.
+func splitPrefixesByFamily(prefixes []netip.Prefix) (v4, v6 []netip.Prefix) {
+	for _, p := range prefixes {
+		if prefixIsV6(p) {
+			v6 = append(v6, p)
+		} else {
+			v4 = append(v4, p)
+		}
+	}
+	return v4, v6
+}
+
+// ruleGroupKey builds the selector key for a rule. v6 must reflect the
+// rule's source family: mgmt emits one rule per family and mixing them
+// would break ICMP-variant selection in uspfilter.
+func ruleGroupKey(r *mgmProto.FirewallRule, v6 bool) peerRuleKey {
+	k := peerRuleKey{
+		v6:         v6,
+		policyID:   string(r.PolicyID),
+		direction:  r.Direction,
+		action:     r.Action,
+		protocol:   r.Protocol,
+		legacyPort: r.Port,
+	}
+	if pi := r.PortInfo; pi != nil {
+		k.port = uint16(pi.GetPort())
+		if rng := pi.GetRange(); rng != nil {
+			k.rangeStart = uint16(rng.GetStart())
+			k.rangeEnd = uint16(rng.GetEnd())
+		}
+	}
+	return k
+}
+
+// extractRuleSources returns all source prefixes the rule applies to.
+// New management populates sourcePrefixes; older management sets PeerIP.
+func extractRuleSources(r *mgmProto.FirewallRule) ([]netip.Prefix, error) {
+	if len(r.SourcePrefixes) > 0 {
+		out := make([]netip.Prefix, 0, len(r.SourcePrefixes))
+		for _, raw := range r.SourcePrefixes {
+			addr, err := netiputil.DecodeAddr(raw)
+			if err != nil {
+				return nil, fmt.Errorf("decode source prefix: %w", err)
+			}
+			out = append(out, netip.PrefixFrom(addr.Unmap(), addr.Unmap().BitLen()))
+		}
+		return out, nil
 	}
 
-	action, err := convertFirewallAction(r.Action)
+	peerIP := r.PeerIP //nolint:staticcheck // PeerIP is the legacy source field for old management servers
+	addr, err := netip.ParseAddr(peerIP)
 	if err != nil {
-		return "", nil, fmt.Errorf("skipping firewall rule: %s", err)
+		return nil, fmt.Errorf("parse peer IP %q: %w", peerIP, err)
 	}
+	addr = addr.Unmap()
+	// An unspecified PeerIP means "any peer" (legacy management
+	// allow-all fallback); only a /0 prefix matches any source in the
+	// backends, a full-length prefix would match nothing.
+	if addr.IsUnspecified() {
+		return []netip.Prefix{netip.PrefixFrom(addr, 0)}, nil
+	}
+	return []netip.Prefix{netip.PrefixFrom(addr, addr.BitLen())}, nil
+}
 
-	var port *firewall.Port
-	if !portInfoEmpty(r.PortInfo) {
-		port = convertPortInfo(r.PortInfo)
-	} else if r.Port != "" {
-		// old version of management, single port
-		value, err := strconv.Atoi(r.Port)
+func resolveGroupPort(g *peerRuleGroup) (*firewall.Port, error) {
+	if !portInfoEmpty(g.port) {
+		return convertPortInfo(g.port), nil
+	}
+	if g.legacyPort != "" {
+		value, err := strconv.ParseUint(g.legacyPort, 10, 16)
 		if err != nil {
-			return "", nil, fmt.Errorf("invalid port: %w", err)
+			return nil, fmt.Errorf("invalid port: %w", err)
 		}
-		port = &firewall.Port{
+		return &firewall.Port{
 			Values: []uint16{uint16(value)},
-		}
+		}, nil
 	}
-
-	ruleID := d.getPeerRuleID(ip, protocol, int(r.Direction), port, action)
-	if rulesPair, ok := d.peerRulesPairs[ruleID]; ok {
-		return ruleID, rulesPair, nil
-	}
-
-	var rules []firewall.Rule
-	switch r.Direction {
-	case mgmProto.RuleDirection_IN:
-		rules, err = d.addInRules(r.PolicyID, ip, protocol, port, action, ipsetName)
-	case mgmProto.RuleDirection_OUT:
-		if d.firewall.IsStateful() {
-			return "", nil, nil
-		}
-		// return traffic for outbound connections if firewall is stateless
-		rules, err = d.addOutRules(r.PolicyID, ip, protocol, port, action, ipsetName)
-	default:
-		return "", nil, fmt.Errorf("invalid direction, skipping firewall rule")
-	}
-
-	if err != nil {
-		return "", nil, err
-	}
-
-	return ruleID, rules, nil
+	// nolint:nilnil // a nil port legitimately means "no port restriction"
+	return nil, nil
 }
 
 func portInfoEmpty(portInfo *mgmProto.PortInfo) bool {
@@ -350,84 +594,9 @@ func portInfoEmpty(portInfo *mgmProto.PortInfo) bool {
 	}
 }
 
-func (d *DefaultManager) addInRules(
-	id []byte,
-	ip netip.Addr,
-	protocol firewall.Protocol,
-	port *firewall.Port,
-	action firewall.Action,
-	ipsetName string,
-) ([]firewall.Rule, error) {
-	rule, err := d.firewall.AddPeerFiltering(id, ip.AsSlice(), protocol, nil, port, action, ipsetName)
-	if err != nil {
-		return nil, fmt.Errorf("add firewall rule: %w", err)
-	}
-
-	return rule, nil
-}
-
-func (d *DefaultManager) addOutRules(
-	id []byte,
-	ip netip.Addr,
-	protocol firewall.Protocol,
-	port *firewall.Port,
-	action firewall.Action,
-	ipsetName string,
-) ([]firewall.Rule, error) {
-	if shouldSkipInvertedRule(protocol, port) {
-		return nil, nil
-	}
-
-	rule, err := d.firewall.AddPeerFiltering(id, ip.AsSlice(), protocol, port, nil, action, ipsetName)
-	if err != nil {
-		return nil, fmt.Errorf("add firewall rule: %w", err)
-	}
-
-	return rule, nil
-}
-
-// getPeerRuleID returns unique ID for the rule based on its parameters.
-func (d *DefaultManager) getPeerRuleID(
-	ip netip.Addr,
-	proto firewall.Protocol,
-	direction int,
-	port *firewall.Port,
-	action firewall.Action,
-) id.RuleID {
-	idStr := ip.String() + string(proto) + strconv.Itoa(direction) + strconv.Itoa(int(action))
-	if port != nil {
-		idStr += port.String()
-	}
-
-	return id.RuleID(hex.EncodeToString(md5.New().Sum([]byte(idStr))))
-}
-
-// getRuleGroupingSelector takes all rule properties except IP address to build selector
-func (d *DefaultManager) getRuleGroupingSelector(rule *mgmProto.FirewallRule) string {
-	return fmt.Sprintf("%v:%v:%v:%s:%v", strconv.Itoa(int(rule.Direction)), rule.Action, rule.Protocol, rule.Port, rule.PortInfo)
-}
-
-// extractRuleIP extracts the peer IP from a firewall rule.
-// If sourcePrefixes is populated (new management), decode the first entry and use its address.
-// Otherwise fall back to the deprecated PeerIP string field (old management).
-func extractRuleIP(r *mgmProto.FirewallRule) (netip.Addr, error) {
-	if len(r.SourcePrefixes) > 0 {
-		addr, err := netiputil.DecodeAddr(r.SourcePrefixes[0])
-		if err != nil {
-			return netip.Addr{}, fmt.Errorf("decode source prefix: %w", err)
-		}
-		return addr.Unmap(), nil
-	}
-
-	//nolint:staticcheck // PeerIP used for backward compatibility with old management
-	addr, err := netip.ParseAddr(r.PeerIP)
-	if err != nil {
-		return netip.Addr{}, fmt.Errorf("invalid IP address, skipping firewall rule")
-	}
-	return addr.Unmap(), nil
-}
-
-func convertToFirewallProtocol(protocol mgmProto.RuleProtocol) (firewall.Protocol, error) {
+// ConvertToFirewallProtocol maps a management rule protocol to the
+// firewall protocol type.
+func ConvertToFirewallProtocol(protocol mgmProto.RuleProtocol) (firewall.Protocol, error) {
 	switch protocol {
 	case mgmProto.RuleProtocol_TCP:
 		return firewall.ProtocolTCP, nil

client/internal/acl/manager_test.go

@@ -10,6 +10,7 @@ import (
 	"go.uber.org/mock/gomock"
 
 	"github.com/netbirdio/netbird/client/firewall"
+	fwmanager "github.com/netbirdio/netbird/client/firewall/manager"
 	"github.com/netbirdio/netbird/client/iface"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
 	"github.com/netbirdio/netbird/client/internal/acl/mocks"
@@ -77,9 +78,9 @@ func TestDefaultManager(t *testing.T) {
 	})
 
 	t.Run("add extra rules", func(t *testing.T) {
-		existedPairs := map[string]struct{}{}
+		existedPairs := map[fwmanager.RuleID]struct{}{}
 		for id := range acl.peerRulesPairs {
-			existedPairs[id.ID()] = struct{}{}
+			existedPairs[id] = struct{}{}
 		}
 
 		// remove first rule
@@ -106,7 +107,7 @@ func TestDefaultManager(t *testing.T) {
 		// check that old rule was removed
 		previousCount := 0
 		for id := range acl.peerRulesPairs {
-			if _, ok := existedPairs[id.ID()]; ok {
+			if _, ok := existedPairs[id]; ok {
 				previousCount++
 			}
 		}

client/internal/connect_test.go

@@ -5,65 +5,78 @@ import (
 	"testing"
 )
 
-func Test_freePort(t *testing.T) {
-	tests := []struct {
-		name        string
-		port        int
-		want        int
-		shouldMatch bool
-	}{
-		{
-			name:        "when port is 0 use random port",
-			port:        0,
-			want:        0,
-			shouldMatch: false,
-		},
-		{
-			name:        "provided and available",
-			port:        51821,
-			want:        51821,
-			shouldMatch: true,
-		},
-		{
-			name:        "provided and not available",
-			port:        51830,
-			want:        51830,
-			shouldMatch: false,
-		},
-	}
-	c1, err := net.ListenUDP("udp", &net.UDPAddr{Port: 0})
+// probeFreePort asks the OS for a free UDP port and immediately releases it.
+// The returned number is only a hint: nothing stops another process from
+// grabbing the same port before the caller gets a chance to bind it.
+//
+// A hardcoded port number is not an option here: any fixed number can fall
+// inside the ephemeral range and be held by an unrelated process on the test
+// runner.
+func probeFreePort(t *testing.T) int {
+	t.Helper()
+
+	conn, err := net.ListenUDP("udp", &net.UDPAddr{Port: 0})
 	if err != nil {
-		t.Errorf("freePort error = %v", err)
+		t.Fatalf("failed to bind probe port: %v", err)
 	}
-	defer func(c1 *net.UDPConn) {
-		_ = c1.Close()
-	}(c1)
-
-	if tests[1].port == c1.LocalAddr().(*net.UDPAddr).Port {
-		tests[1].port++
-		tests[1].want++
-	}
-
-	tests[2].port = c1.LocalAddr().(*net.UDPAddr).Port
-	tests[2].want = c1.LocalAddr().(*net.UDPAddr).Port
-
-	for _, tt := range tests {
-
-		t.Run(tt.name, func(t *testing.T) {
-			got, err := freePort(tt.port)
-
-			if err != nil {
-				t.Errorf("got an error while getting free port: %v", err)
-			}
-
-			if tt.shouldMatch && got != tt.want {
-				t.Errorf("got a different port %v, want %v", got, tt.want)
-			}
-
-			if !tt.shouldMatch && got == tt.want {
-				t.Errorf("got the same port %v, want a different port", tt.want)
-			}
-		})
-
+	port := conn.LocalAddr().(*net.UDPAddr).Port
+	if err := conn.Close(); err != nil {
+		t.Fatalf("failed to close probe port: %v", err)
 	}
+	return port
+}
+
+func Test_freePort(t *testing.T) {
+	t.Run("when port is 0 use random port", func(t *testing.T) {
+		got, err := freePort(0)
+		if err != nil {
+			t.Fatalf("got an error while getting free port: %v", err)
+		}
+		if got == 0 {
+			t.Errorf("got port 0, want a non-zero random port")
+		}
+	})
+
+	t.Run("provided and available", func(t *testing.T) {
+		const maxAttempts = 5
+
+		// The probed port is released before freePort binds it, so an
+		// unrelated process on the test runner can grab it in between,
+		// making freePort fall back to a different port. Retry with a
+		// freshly probed port instead of failing on a lost race.
+		for attempt := 1; attempt <= maxAttempts; attempt++ {
+			candidate := probeFreePort(t)
+
+			got, err := freePort(candidate)
+			if err != nil {
+				t.Fatalf("got an error while getting free port: %v", err)
+			}
+
+			if got == candidate {
+				return
+			}
+			t.Logf("attempt %d: freePort returned %d instead of the requested %d, retrying", attempt, got, candidate)
+		}
+
+		t.Fatalf("freePort did not return the requested free port after %d attempts", maxAttempts)
+	})
+
+	t.Run("provided and not available", func(t *testing.T) {
+		busy, err := net.ListenUDP("udp", &net.UDPAddr{Port: 0})
+		if err != nil {
+			t.Fatalf("failed to bind busy port: %v", err)
+		}
+		t.Cleanup(func() {
+			_ = busy.Close()
+		})
+		busyPort := busy.LocalAddr().(*net.UDPAddr).Port
+
+		got, err := freePort(busyPort)
+		if err != nil {
+			t.Fatalf("got an error while getting free port: %v", err)
+		}
+		if got == busyPort {
+			t.Errorf("got the same port %v, want a different port", busyPort)
+		}
+	})
 }

client/internal/dns/server_test.go

@@ -423,7 +423,7 @@ func createWgInterfaceWithBind(t *testing.T) (*iface.WGIface, error) {
 		return nil, err
 	}
 
-	pf, err := uspfilter.Create(wgIface, false, flowLogger, iface.DefaultMTU)
+	pf, err := uspfilter.Create(uspfilter.Config{IFace: wgIface, FlowLogger: flowLogger, MTU: iface.DefaultMTU})
 	if err != nil {
 		t.Fatalf("failed to create uspfilter: %v", err)
 		return nil, err

client/internal/dnsfwd/forwarder.go

@@ -54,12 +54,20 @@ type DNSForwarder struct {
 	ttl            uint32
 	statusRecorder *peer.Status
 
-	dnsServer *dns.Server
-	mux       *dns.ServeMux
-	tcpServer *dns.Server
-	tcpMux    *dns.ServeMux
+	mux    *dns.ServeMux
+	tcpMux *dns.ServeMux
 
-	mutex      sync.RWMutex
+	mutex sync.RWMutex
+	// closed records that Close has run, so a Listen still in flight does not
+	// go on to serve sockets nobody will shut down.
+	closed bool
+	// The sockets are kept alongside the servers because closing them is the
+	// only stop that always works: a server whose ActivateAndServe has not run
+	// yet refuses to shut down, and would otherwise start serving afterwards.
+	udpConn    net.PacketConn
+	tcpLn      net.Listener
+	dnsServer  *dns.Server
+	tcpServer  *dns.Server
 	fwdEntries []*ForwarderEntry
 	firewall   firewaller
 	resolver   resolver
@@ -106,7 +114,7 @@ func (f *DNSForwarder) Listen(entries []*ForwarderEntry) error {
 	mux := dns.NewServeMux()
 	f.mux = mux
 	mux.HandleFunc(".", f.handleDNSQueryUDP)
-	f.dnsServer = &dns.Server{
+	dnsServer := &dns.Server{
 		PacketConn: udpLn,
 		Handler:    mux,
 	}
@@ -114,22 +122,32 @@ func (f *DNSForwarder) Listen(entries []*ForwarderEntry) error {
 	tcpMux := dns.NewServeMux()
 	f.tcpMux = tcpMux
 	tcpMux.HandleFunc(".", f.handleDNSQueryTCP)
-	f.tcpServer = &dns.Server{
+	tcpServer := &dns.Server{
 		Listener: tcpLn,
 		Handler:  tcpMux,
 	}
 
-	f.UpdateDomains(entries)
+	if !f.publish(udpLn, tcpLn, dnsServer, tcpServer, entries) {
+		log.Infof("DNS forwarder on %s was closed before it started serving", addrDesc)
+		if err := udpLn.Close(); err != nil {
+			log.Debugf("close UDP listener of a closed forwarder: %v", err)
+		}
+		if err := tcpLn.Close(); err != nil {
+			log.Debugf("close TCP listener of a closed forwarder: %v", err)
+		}
+		return nil
+	}
+	log.Debugf("DNS forwarder serving %d domains", len(entries))
 
 	errCh := make(chan error, 2)
 
 	go func() {
 		log.Infof("DNS UDP listener running on %s", addrDesc)
-		errCh <- f.dnsServer.ActivateAndServe()
+		errCh <- dnsServer.ActivateAndServe()
 	}()
 	go func() {
 		log.Infof("DNS TCP listener running on %s", addrDesc)
-		errCh <- f.tcpServer.ActivateAndServe()
+		errCh <- tcpServer.ActivateAndServe()
 	}()
 
 	return <-errCh
@@ -151,6 +169,46 @@ func (f *DNSForwarder) createTCPListener(netstackNet *netstack.Net) (net.Listene
 	return net.ListenTCP("tcp", net.TCPAddrFromAddrPort(f.listenAddress))
 }
 
+// publish hands the sockets, servers and entries to the forwarder so Close can
+// reach them and Domains can report them, and says whether serving may begin.
+// Listen runs on its own goroutine, so a Close can arrive before it gets this
+// far; false means the caller must close what it created instead of serving on
+// it.
+//
+// The entries go in under the same lock rather than afterwards. Anything that
+// reads them in between would otherwise see a forwarder that is listening and
+// serves no domain, which for a caller rebuilding one means it comes back
+// refusing every routed query.
+func (f *DNSForwarder) publish(
+	udpConn net.PacketConn,
+	tcpLn net.Listener,
+	dnsServer, tcpServer *dns.Server,
+	entries []*ForwarderEntry,
+) bool {
+	f.mutex.Lock()
+	defer f.mutex.Unlock()
+
+	if f.closed {
+		return false
+	}
+
+	f.udpConn = udpConn
+	f.tcpLn = tcpLn
+	f.dnsServer = dnsServer
+	f.tcpServer = tcpServer
+	f.fwdEntries = entries
+	return true
+}
+
+// Domains returns the entries currently being served. The slice is replaced
+// wholesale by UpdateDomains rather than mutated, so the caller may read it but
+// must not write to it.
+func (f *DNSForwarder) Domains() []*ForwarderEntry {
+	f.mutex.RLock()
+	defer f.mutex.RUnlock()
+	return f.fwdEntries
+}
+
 func (f *DNSForwarder) UpdateDomains(entries []*ForwarderEntry) {
 	f.mutex.Lock()
 	defer f.mutex.Unlock()
@@ -189,19 +247,45 @@ func (f *DNSForwarder) removeStaleCacheEntries(oldEntries, newEntries []*Forward
 }
 
 func (f *DNSForwarder) Close(ctx context.Context) error {
+	// Marked closed under the lock so a Listen that has not published its
+	// servers yet gives up instead of racing this shutdown. The shutdowns
+	// themselves block, so they run outside it.
+	f.mutex.Lock()
+	f.closed = true
+	dnsServer, tcpServer := f.dnsServer, f.tcpServer
+	udpConn, tcpLn := f.udpConn, f.tcpLn
+	f.mutex.Unlock()
+
 	var result *multierror.Error
 
-	if f.dnsServer != nil {
-		if err := f.dnsServer.ShutdownContext(ctx); err != nil {
+	if dnsServer != nil {
+		if err := shutdownServer(ctx, dnsServer); err != nil {
 			result = multierror.Append(result, fmt.Errorf("UDP shutdown: %w", err))
 		}
 	}
-	if f.tcpServer != nil {
-		if err := f.tcpServer.ShutdownContext(ctx); err != nil {
+	if tcpServer != nil {
+		if err := shutdownServer(ctx, tcpServer); err != nil {
 			result = multierror.Append(result, fmt.Errorf("TCP shutdown: %w", err))
 		}
 	}
 
+	// The sockets are closed even when the shutdowns above reported nothing to
+	// do. A server that has been published but has not reached
+	// ActivateAndServe refuses to shut down, and closing what it was about to
+	// serve on is what stops it: the alternative is a listener still answering
+	// on an interface that has gone away. A shutdown that did run has already
+	// closed these, so the second close is expected to fail.
+	if udpConn != nil {
+		if err := udpConn.Close(); err != nil {
+			log.Debugf("close UDP socket of the DNS forwarder: %v", err)
+		}
+	}
+	if tcpLn != nil {
+		if err := tcpLn.Close(); err != nil {
+			log.Debugf("close TCP socket of the DNS forwarder: %v", err)
+		}
+	}
+
 	return nberrors.FormatErrorOrNil(result)
 }
 
@@ -514,3 +598,16 @@ func attachEDE(resp *dns.Msg, code uint16, text string) {
 	}
 	opt.Option = append(opt.Option, &dns.EDNS0_EDE{InfoCode: code, ExtraText: text})
 }
+
+// shutdownServer shuts a server down gracefully, treating "never started" as
+// success. A server that was published but has not reached ActivateAndServe
+// has nothing to wind down, and the caller closes its socket regardless, which
+// is what actually stops it. dns exports no sentinel for this, so the message
+// is all there is to match on.
+func shutdownServer(ctx context.Context, server *dns.Server) error {
+	err := server.ShutdownContext(ctx)
+	if err == nil || strings.Contains(err.Error(), "server not started") {
+		return nil
+	}
+	return err
+}

client/internal/dnsfwd/forwarder_test.go

@@ -1238,3 +1238,55 @@ func TestDNSForwarder_EmptyQuery(t *testing.T) {
 
 	assert.Nil(t, mockWriter.GetLastResponse(), "Should not write response for empty query")
 }
+
+// TestDNSForwarder_ClosedBeforeItServes covers Listen reaching the point of
+// serving after the forwarder has already been closed. Listen runs on its own
+// goroutine, so it can get there late, and a socket it starts serving then is
+// one nothing will ever close: on Android it keeps answering on an interface
+// that has been replaced. The close is sequenced first here rather than raced,
+// which pins the same state deterministically.
+func TestDNSForwarder_ClosedBeforeItServes(t *testing.T) {
+	f := NewDNSForwarder(netip.MustParseAddrPort("127.0.0.1:0"), 60, nil, nil, nil)
+
+	require.NoError(t, f.Close(context.Background()), "closing a forwarder that never started")
+
+	done := make(chan error, 1)
+	go func() { done <- f.Listen(nil) }()
+
+	select {
+	case err := <-done:
+		assert.NoError(t, err, "a closed forwarder should give up quietly, not serve")
+	case <-time.After(5 * time.Second):
+		t.Fatal("Listen went on to serve after the forwarder was closed")
+	}
+}
+
+// TestDNSForwarder_CloseStopsUnactivatedServers covers the window between
+// Listen publishing its servers and reaching ActivateAndServe. A server that
+// has not been activated refuses to shut down, so Close has to close the
+// sockets itself or they are left serving.
+func TestDNSForwarder_CloseStopsUnactivatedServers(t *testing.T) {
+	f := NewDNSForwarder(netip.MustParseAddrPort("127.0.0.1:0"), 60, nil, nil, nil)
+
+	udpConn, err := f.createUDPListener(nil)
+	require.NoError(t, err, "create UDP listener")
+	tcpLn, err := f.createTCPListener(nil)
+	require.NoError(t, err, "create TCP listener")
+
+	// Published but deliberately never activated, which is the state Listen is
+	// in for the moment before it starts serving.
+	require.True(t, f.publish(udpConn, tcpLn, &dns.Server{PacketConn: udpConn}, &dns.Server{Listener: tcpLn}, nil),
+		"publishing to an open forwarder")
+
+	tcpAddr := tcpLn.Addr().String()
+	require.NoError(t, f.Close(context.Background()), "close should report no error for servers it could not shut down")
+
+	_, err = tcpLn.Accept()
+	assert.Error(t, err, "the TCP socket should be closed after Close")
+
+	conn, err := net.DialTimeout("tcp", tcpAddr, time.Second)
+	if err == nil {
+		_ = conn.Close()
+		t.Fatal("the forwarder is still accepting connections after Close")
+	}
+}

client/internal/dnsfwd/manager.go

@@ -3,7 +3,6 @@ package dnsfwd
 import (
 	"context"
 	"fmt"
-	"net"
 	"net/netip"
 	"os"
 	"strconv"
@@ -118,6 +117,16 @@ func (m *Manager) UpdateDomains(entries []*ForwarderEntry) {
 	m.dnsForwarder.UpdateDomains(entries)
 }
 
+// Domains returns the entries currently being served, or nil when the
+// forwarder is not running.
+func (m *Manager) Domains() []*ForwarderEntry {
+	if m.dnsForwarder == nil {
+		return nil
+	}
+
+	return m.dnsForwarder.Domains()
+}
+
 func (m *Manager) Stop(ctx context.Context) error {
 	if m.dnsForwarder == nil {
 		return nil
@@ -160,12 +169,13 @@ func (m *Manager) allowDNSFirewall() error {
 		return nil
 	}
 
-	dnsRules, err := m.firewall.AddPeerFiltering(nil, net.IP{0, 0, 0, 0}, firewall.ProtocolUDP, nil, dport, firewall.ActionAccept, "")
+	anyV4 := []netip.Prefix{netip.PrefixFrom(netip.IPv4Unspecified(), 0)}
+	dnsRule, err := m.firewall.AddFilterRule(nil, anyV4, firewall.Network{}, firewall.ProtocolUDP, nil, dport, firewall.ActionAccept)
 	if err != nil {
 		return fmt.Errorf("add udp firewall rule: %w", err)
 	}
 
-	tcpRules, err := m.firewall.AddPeerFiltering(nil, net.IP{0, 0, 0, 0}, firewall.ProtocolTCP, nil, dport, firewall.ActionAccept, "")
+	tcpRule, err := m.firewall.AddFilterRule(nil, anyV4, firewall.Network{}, firewall.ProtocolTCP, nil, dport, firewall.ActionAccept)
 	if err != nil {
 		return fmt.Errorf("add tcp firewall rule: %w", err)
 	}
@@ -174,8 +184,12 @@ func (m *Manager) allowDNSFirewall() error {
 		return fmt.Errorf("flush: %w", err)
 	}
 
-	m.fwRules = dnsRules
-	m.tcpRules = tcpRules
+	if dnsRule != nil {
+		m.fwRules = []firewall.Rule{dnsRule}
+	}
+	if tcpRule != nil {
+		m.tcpRules = []firewall.Rule{tcpRule}
+	}
 
 	m.registerNetstackServices()
 
@@ -209,12 +223,12 @@ func (m *Manager) unregisterNetstackServices() {
 func (m *Manager) dropDNSFirewall() error {
 	var mErr *multierror.Error
 	for _, rule := range m.fwRules {
-		if err := m.firewall.DeletePeerRule(rule); err != nil {
+		if err := m.firewall.DeleteFilterRule(rule); err != nil {
 			mErr = multierror.Append(mErr, fmt.Errorf("failed to delete DNS router rules, err: %v", err))
 		}
 	}
 	for _, rule := range m.tcpRules {
-		if err := m.firewall.DeletePeerRule(rule); err != nil {
+		if err := m.firewall.DeleteFilterRule(rule); err != nil {
 			mErr = multierror.Append(mErr, fmt.Errorf("failed to delete DNS router rules, err: %v", err))
 		}
 	}

client/internal/engine.go

@@ -95,6 +95,13 @@ const (
 	// exec, os.Stat); without this bound a single stuck call freezes handleSync, and
 	// thus syncMsgMux, for as long as the call hangs (observed multi-minute freezes).
 	systemInfoTimeout = 15 * time.Second
+
+	// dnsForwarderStopTimeout bounds how long stopping the DNS forwarder waits
+	// for the queries still in flight. One waiting on an unresponsive upstream
+	// would otherwise hold the stop for the whole upstream timeout, and the
+	// stop runs with syncMsgMux held. The sockets are closed either way, so
+	// giving up costs a query that was already failing.
+	dnsForwarderStopTimeout = 2 * time.Second
 )
 
 var ErrResetConnection = fmt.Errorf("reset connection")
@@ -264,6 +271,8 @@ type Engine struct {
 	// checks are the client-applied posture checks that need to be evaluated on the client
 	checks []*mgmProto.Checks
 
+	infoSource system.InfoSource
+
 	relayManager       *relayClient.Manager
 	stateManager       *statemanager.Manager
 	portForwardManager *portforward.Manager
@@ -327,6 +336,10 @@ type localIpUpdater interface {
 	UpdateLocalIPs() error
 }
 
+// overlayRebind rebuilds one subsystem's sockets on the current interface. The
+// error it returns names its own subsystem, since the caller can only log it.
+type overlayRebind func() error
+
 // NewEngine creates a new Connection Engine with probes attached
 func NewEngine(
 	clientCtx context.Context,
@@ -754,6 +767,11 @@ func (e *Engine) initFirewall() error {
 		return fmt.Errorf("set firewall: %w", err)
 	}
 
+	// TODO: the firewall backends dedup filter rules by content, so a
+	// management route ACL with identical content would collapse onto the
+	// untracked drop rules installed here, and a later management delete
+	// could remove them. Needs backend refcounting or per-consumer key
+	// namespacing.
 	if e.config.BlockLANAccess {
 		e.blockLanAccess()
 	}
@@ -766,14 +784,14 @@ func (e *Engine) initFirewall() error {
 	port := firewallManager.Port{Values: []uint16{uint16(rosenpassPort)}}
 
 	// IPv4-only: rosenpass peers connect via AllowedIps[0] which is always v4.
-	if _, err := e.firewall.AddPeerFiltering(
+	if _, err := e.firewall.AddFilterRule(
 		nil,
-		net.IP{0, 0, 0, 0},
+		[]netip.Prefix{netip.PrefixFrom(netip.IPv4Unspecified(), 0)},
+		firewallManager.Network{},
 		firewallManager.ProtocolUDP,
 		nil,
 		&port,
 		firewallManager.ActionAccept,
-		"",
 	); err != nil {
 		log.Errorf("failed to allow rosenpass interface traffic: %v", err)
 		return nil
@@ -823,7 +841,7 @@ func (e *Engine) blockLanAccess() {
 		if network.Addr().Is6() {
 			source = v6
 		}
-		if _, err := e.firewall.AddRouteFiltering(
+		if _, err := e.firewall.AddFilterRule(
 			nil,
 			[]netip.Prefix{source},
 			firewallManager.Network{Prefix: network},
@@ -1234,9 +1252,7 @@ func (e *Engine) updateChecksIfNew(checks []*mgmProto.Checks) error {
 	if isChecksEqual(e.checks, checks) {
 		return nil
 	}
-	e.checks = checks
-
-	info, ok := system.GetInfoWithChecksTimeout(e.ctx, systemInfoTimeout, checks, e.overlayAddresses()...)
+	info, ok := e.infoSource.Refresh(e.ctx, systemInfoTimeout, checks, e.overlayAddresses()...)
 	if !ok {
 		// Gathering timed out; skip the meta sync this cycle rather than blocking the
 		// sync loop (and syncMsgMux) on a stuck system call. A later sync will retry.
@@ -1247,6 +1263,7 @@ func (e *Engine) updateChecksIfNew(checks []*mgmProto.Checks) error {
 	if err := e.mgmClient.SyncMeta(info); err != nil {
 		return fmt.Errorf("could not sync meta: error %s", err)
 	}
+	e.checks = checks
 	return nil
 }
 
@@ -1273,6 +1290,28 @@ func (e *Engine) applyInfoFlags(info *system.Info) {
 	)
 }
 
+func (e *Engine) currentSystemInfo(ctx context.Context) *system.Info {
+	info := e.infoSource.Current(ctx, e.overlayAddresses()...)
+	e.applyInfoFlags(info)
+	return info
+}
+
+// syncInfoFunc returns the info callback for the management sync stream. The
+// first connect sends the info refreshed right before it instead of gathering
+// again; every reconnect gathers a fresh one. The stream retry loop calls the
+// callback sequentially, so the handoff needs no synchronization.
+func (e *Engine) syncInfoFunc(refreshed *system.Info) func(ctx context.Context) *system.Info {
+	return func(ctx context.Context) *system.Info {
+		if refreshed == nil {
+			return e.currentSystemInfo(ctx)
+		}
+		info := refreshed
+		refreshed = nil
+		e.applyInfoFlags(info)
+		return info
+	}
+}
+
 // overlayAddresses returns our own WireGuard overlay address (v4 and v6) so it
 // can be excluded from the reported network addresses; the interface coming and
 // going otherwise churns the peer meta on the management server.
@@ -1468,15 +1507,11 @@ func (e *Engine) receiveManagementEvents() {
 	e.shutdownWg.Add(1)
 	go func() {
 		defer e.shutdownWg.Done()
-		info, ok := system.GetInfoWithChecksTimeout(e.ctx, systemInfoTimeout, e.checks, e.overlayAddresses()...)
+		info, ok := e.infoSource.Refresh(e.ctx, systemInfoTimeout, e.checks, e.overlayAddresses()...)
 		if !ok {
-			// Gathering timed out; connect the stream with base info so management
-			// connectivity still comes up rather than blocking here.
-			info = system.GetInfo(e.ctx)
+			log.Warnf("posture checks not refreshed before the sync connect, sending the previous results")
 		}
-		e.applyInfoFlags(info)
-
-		err := e.mgmClient.Sync(e.ctx, info, e.handleSync)
+		err := e.mgmClient.Sync(e.ctx, e.syncInfoFunc(info), e.handleSync)
 		if err != nil {
 			// happens if management is unavailable for a long time.
 			// We want to cancel the operation of the whole client
@@ -2514,7 +2549,68 @@ func (e *Engine) RenewTun(fd int) error {
 		return err
 	}
 
-	e.restartFileDrop()
+	e.rebindOverlayListeners()
+	return nil
+}
+
+// rebindOverlayListeners gives the servers that listen on an overlay address
+// sockets on the interface as it is now.
+//
+// A socket belongs to the interface generation it was created on. Renewing the
+// TUN builds a new interface and moves the overlay addresses to it, which
+// leaves the old sockets in LISTEN with the uspfilter still logging packets
+// arriving for them, while every accept fails with EINVAL for the life of the
+// socket: from the outside the server looks alive and answers nothing. On
+// Android this happens during a normal startup, where the first TUN is
+// established before the routes are known and replaced once they arrive.
+//
+// Rebinding costs whatever those sockets were carrying, which the renewal has
+// already broken. Errors are logged rather than returned: the renewal itself
+// succeeded, and failing it would hand the caller a working interface and an
+// error.
+func (e *Engine) rebindOverlayListeners() {
+	e.syncMsgMux.Lock()
+	defer e.syncMsgMux.Unlock()
+
+	for _, rebind := range e.overlayRebinds() {
+		if err := rebind(); err != nil {
+			log.Errorf("after TUN renewal: %v", err)
+		}
+	}
+}
+
+// overlayRebinds is every subsystem of this engine that holds sockets bound to
+// an overlay address, and how to rebuild each one's.
+//
+// A subsystem that starts listening on an overlay address belongs in this list.
+// Leaving it out costs nothing that review would notice and produces a listener
+// that stays in LISTEN, is logged as receiving packets, and refuses every
+// connection for the life of the process.
+func (e *Engine) overlayRebinds() []overlayRebind {
+	return []overlayRebind{
+		e.restartSSHListeners,
+		e.restartDNSForwarder,
+		e.restartFileDrop,
+	}
+}
+
+// restartDNSForwarder rebuilds the DNS forwarder serving the same domains.
+// No-op when it is not running. See Engine.rebindOverlayListeners.
+func (e *Engine) restartDNSForwarder() error {
+	if e.dnsForwardMgr == nil {
+		return nil
+	}
+	// Read from the forwarder before it goes away, so the replacement serves
+	// the domains in force now rather than a copy kept somewhere else.
+	entries := e.dnsForwardMgr.Domains()
+	e.stopDNSForwarder()
+	// Both halves log their own failures, so the only thing left to report is
+	// the outcome: a start that failed left the manager nil, and the forwarder
+	// is now down rather than merely rebound.
+	e.startDNSForwarder(entries)
+	if e.dnsForwardMgr == nil {
+		return errors.New("rebind DNS forwarder: it did not come back up")
+	}
 	return nil
 }
 
@@ -2561,7 +2657,14 @@ func (e *Engine) stopDNSForwarder() {
 		return
 	}
 
-	if err := e.dnsForwardMgr.Stop(context.Background()); err != nil {
+	// Bounded because the shutdown waits for queries still in flight, and one
+	// waiting on an unresponsive upstream holds it for as long as that lookup
+	// is allowed to take. This runs with syncMsgMux held, so that wait is one
+	// the whole engine spends.
+	ctx, cancel := context.WithTimeout(context.Background(), dnsForwarderStopTimeout)
+	defer cancel()
+
+	if err := e.dnsForwardMgr.Stop(ctx); err != nil {
 		log.Errorf("failed to stop DNS forward: %v", err)
 	}
 
@@ -2676,7 +2779,7 @@ func (e *Engine) updateForwardRules(rules []*mgmProto.ForwardingRule) ([]firewal
 	var merr *multierror.Error
 	forwardingRules := make([]firewallManager.ForwardRule, 0, len(rules))
 	for _, rule := range rules {
-		proto, err := convertToFirewallProtocol(rule.GetProtocol())
+		proto, err := acl.ConvertToFirewallProtocol(rule.GetProtocol())
 		if err != nil {
 			merr = multierror.Append(merr, fmt.Errorf("failed to convert protocol '%s': %w", rule.GetProtocol(), err))
 			continue

client/internal/engine_filedrop.go

@@ -141,16 +141,15 @@ func (e *Engine) setFileDropTunnel() {
 // device. The listeners are bound to the overlay address of the interface being
 // swapped out and do not survive it: Android renews the tun on every route
 // change, which leaves the IPv4 listener dead with accept4: invalid argument.
-func (e *Engine) restartFileDrop() {
-	e.syncMsgMux.Lock()
-	defer e.syncMsgMux.Unlock()
-
+// No-op when it is not running. See Engine.rebindOverlayListeners.
+func (e *Engine) restartFileDrop() error {
 	if e.fileDrop == nil || !e.fileDropRunning || e.wgInterface == nil {
-		return
+		return nil
 	}
 
 	e.stopFileDrop()
 	e.startFileDrop()
+	return nil
 }
 
 func (e *Engine) stopFileDrop() {

client/internal/engine_privileged_test.go

@@ -193,7 +193,7 @@ func TestEngine_Sync(t *testing.T) {
 	// feed updates to Engine via mocked Management client
 	updates := make(chan *mgmtProto.SyncResponse)
 	defer close(updates)
-	syncFunc := func(ctx context.Context, info *system.Info, msgHandler func(msg *mgmtProto.SyncResponse) error) error {
+	syncFunc := func(ctx context.Context, _ func(context.Context) *system.Info, msgHandler func(msg *mgmtProto.SyncResponse) error) error {
 		for msg := range updates {
 			err := msgHandler(msg)
 			if err != nil {

client/internal/engine_ssh.go

@@ -24,6 +24,8 @@ type sshServer interface {
 	Stop() error
 	GetStatus() (bool, []sshserver.SessionInfo)
 	UpdateSSHAuth(config *sshauth.Config)
+	JWTConfig() *sshserver.JWTConfig
+	AuthConfig() *sshauth.Config
 }
 
 func (e *Engine) setupSSHPortRedirection() error {
@@ -77,7 +79,7 @@ func (e *Engine) updateSSH(sshConf *mgmProto.SSHConfig) error {
 
 	if e.config.DisableSSHAuth != nil && *e.config.DisableSSHAuth {
 		log.Info("starting SSH server without JWT authentication (authentication disabled by config)")
-		return e.startSSHServer(nil)
+		return e.startSSHServer(nil, nil)
 	}
 
 	if protoJWT := sshConf.GetJwtConfig(); protoJWT != nil {
@@ -95,7 +97,7 @@ func (e *Engine) updateSSH(sshConf *mgmProto.SSHConfig) error {
 			MaxTokenAge:  protoJWT.GetMaxTokenAge(),
 		}
 
-		return e.startSSHServer(jwtConfig)
+		return e.startSSHServer(jwtConfig, nil)
 	}
 
 	return errors.New("SSH server requires valid JWT configuration")
@@ -231,8 +233,33 @@ func (e *Engine) cleanupSSHConfig() {
 	}
 }
 
-// startSSHServer initializes and starts the SSH server with proper configuration.
-func (e *Engine) startSSHServer(jwtConfig *sshserver.JWTConfig) error {
+// restartSSHListeners rebuilds the SSH server so it listens on new sockets, on
+// the same terms it was started with. No-op when it is not running. See
+// Engine.rebindOverlayListeners for why this is needed.
+func (e *Engine) restartSSHListeners() error {
+	if e.sshServer == nil {
+		return nil
+	}
+	// Read from the server before it goes away. A rebuilt one starts with an
+	// empty authorizer, which fails closed, so without carrying the
+	// authorization over every JWT login is refused until the next network map
+	// happens to bring one.
+	jwtConfig, authConfig := e.sshServer.JWTConfig(), e.sshServer.AuthConfig()
+	if err := e.stopSSHServer(); err != nil {
+		return fmt.Errorf("rebind SSH listeners: %w", err)
+	}
+	if err := e.startSSHServer(jwtConfig, authConfig); err != nil {
+		return fmt.Errorf("rebind SSH listeners: %w", err)
+	}
+	return nil
+}
+
+// startSSHServer initializes and starts the SSH server with proper
+// configuration. authConfig is the fine-grained authorization to open with, and
+// is applied before the server accepts anything: a server that starts listening
+// with an empty authorizer refuses the logins that arrive in the meantime.
+// Nil leaves it as management has not sent one yet.
+func (e *Engine) startSSHServer(jwtConfig *sshserver.JWTConfig, authConfig *sshauth.Config) error {
 	if e.wgInterface == nil {
 		return errors.New("wg interface not initialized")
 	}
@@ -240,6 +267,7 @@ func (e *Engine) startSSHServer(jwtConfig *sshserver.JWTConfig) error {
 	serverConfig := &sshserver.Config{
 		HostKeyPEM: e.config.SSHKey,
 		JWT:        jwtConfig,
+		Auth:       authConfig,
 	}
 	server := sshserver.New(serverConfig)
 

client/internal/engine_test.go

@@ -2,6 +2,7 @@ package internal
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"net"
 	"net/netip"
@@ -31,6 +32,7 @@ import (
 	icemaker "github.com/netbirdio/netbird/client/internal/peer/ice"
 	"github.com/netbirdio/netbird/client/internal/profilemanager"
 	"github.com/netbirdio/netbird/client/internal/routemanager"
+	"github.com/netbirdio/netbird/client/system"
 	nbdns "github.com/netbirdio/netbird/dns"
 	"github.com/netbirdio/netbird/monotime"
 	"github.com/netbirdio/netbird/route"
@@ -253,6 +255,118 @@ func TestEngine_SSHServerConsistency(t *testing.T) {
 	})
 }
 
+func TestEngine_FirstSyncInfoCarriesLoginChecks(t *testing.T) {
+	key, err := wgtypes.GeneratePrivateKey()
+	require.NoError(t, err)
+
+	exe, err := os.Executable()
+	require.NoError(t, err)
+
+	ctx, cancel := context.WithCancel(CtxInitState(context.Background()))
+	defer cancel()
+
+	infos := make(chan *system.Info, 1)
+	mgmClient := &mgmt.MockClient{
+		SyncFunc: func(ctx context.Context, getInfo func(context.Context) *system.Info, _ func(*mgmtProto.SyncResponse) error) error {
+			infos <- getInfo(ctx)
+			return nil
+		},
+	}
+
+	relayMgr := relayClient.NewManager(ctx, nil, key.PublicKey().String(), iface.DefaultMTU)
+	engine := NewEngine(ctx, cancel, &EngineConfig{
+		WgIfaceName:  "utun104",
+		WgAddr:       wgaddr.MustParseWGAddress("100.64.0.1/24"),
+		WgPrivateKey: key,
+		WgPort:       33100,
+		MTU:          iface.DefaultMTU,
+	}, EngineServices{
+		SignalClient:   &signal.MockClient{},
+		MgmClient:      mgmClient,
+		RelayManager:   relayMgr,
+		StatusRecorder: peer.NewRecorder("https://mgm"),
+		Checks:         []*mgmtProto.Checks{{Files: []string{exe}}},
+	}, MobileDependency{})
+
+	engine.receiveManagementEvents()
+
+	select {
+	case info := <-infos:
+		require.Len(t, info.Files, 1)
+		assert.Equal(t, exe, info.Files[0].Path)
+		assert.True(t, info.Files[0].Exist)
+	case <-time.After(20 * time.Second):
+		t.Fatal("timeout waiting for the first sync info")
+	}
+	engine.shutdownWg.Wait()
+}
+
+func TestEngine_SyncInfoFuncReusesRefreshedInfoOnce(t *testing.T) {
+	engine := &Engine{config: &EngineConfig{}}
+
+	refreshed := &system.Info{Hostname: "from-refresh"}
+	getInfo := engine.syncInfoFunc(refreshed)
+
+	first := getInfo(context.Background())
+	assert.Same(t, refreshed, first, "the first connect should send the refreshed info instead of gathering again")
+
+	second := getInfo(context.Background())
+	assert.NotSame(t, refreshed, second, "the reconnect should gather a fresh info")
+	assert.NotEqual(t, "from-refresh", second.Hostname, "the fresh info should not carry the refreshed hostname")
+}
+
+func TestEngine_SyncInfoFuncGathersWhenRefreshFailed(t *testing.T) {
+	engine := &Engine{config: &EngineConfig{}}
+
+	info := engine.syncInfoFunc(nil)(context.Background())
+	require.NotNil(t, info, "a failed refresh should fall back to gathering the info")
+	assert.NotEmpty(t, info.Hostname, "the gathered info should carry the hostname")
+}
+
+func TestEngine_UpdateChecksIfNewRetriesAfterFailedSyncMeta(t *testing.T) {
+	key, err := wgtypes.GeneratePrivateKey()
+	require.NoError(t, err)
+
+	exe, err := os.Executable()
+	require.NoError(t, err)
+
+	ctx, cancel := context.WithCancel(CtxInitState(context.Background()))
+	defer cancel()
+
+	syncMetaCalls := 0
+	mgmClient := &mgmt.MockClient{
+		SyncMetaFunc: func(*system.Info) error {
+			syncMetaCalls++
+			if syncMetaCalls == 1 {
+				return errors.New("management unavailable")
+			}
+			return nil
+		},
+	}
+
+	relayMgr := relayClient.NewManager(ctx, nil, key.PublicKey().String(), iface.DefaultMTU)
+	engine := NewEngine(ctx, cancel, &EngineConfig{
+		WgIfaceName:  "utun105",
+		WgAddr:       wgaddr.MustParseWGAddress("100.64.0.1/24"),
+		WgPrivateKey: key,
+		WgPort:       33100,
+		MTU:          iface.DefaultMTU,
+	}, EngineServices{
+		SignalClient:   &signal.MockClient{},
+		MgmClient:      mgmClient,
+		RelayManager:   relayMgr,
+		StatusRecorder: peer.NewRecorder("https://mgm"),
+	}, MobileDependency{})
+
+	checks := []*mgmtProto.Checks{{Files: []string{exe}}}
+
+	require.Error(t, engine.updateChecksIfNew(checks))
+	require.NoError(t, engine.updateChecksIfNew(checks))
+	require.NoError(t, engine.updateChecksIfNew(checks))
+
+	assert.Equal(t, 2, syncMetaCalls)
+}
+
 func TestEngine_UpdateNetworkMap(t *testing.T) {
 	// test setup
 	key, err := wgtypes.GeneratePrivateKey()

client/internal/ingressgw/manager.go

@@ -24,14 +24,14 @@ type RulePair struct {
 type Manager struct {
 	dnatFirewall DNATFirewall
 
-	rules   map[string]RulePair // keys is the ID of the ForwardRule
+	rules   map[firewall.RuleID]RulePair
 	rulesMu sync.Mutex
 }
 
 func NewManager(dnatFirewall DNATFirewall) *Manager {
 	return &Manager{
 		dnatFirewall: dnatFirewall,
-		rules:        make(map[string]RulePair),
+		rules:        make(map[firewall.RuleID]RulePair),
 	}
 }
 
@@ -41,7 +41,7 @@ func (h *Manager) Update(forwardRules []firewall.ForwardRule) error {
 
 	var mErr *multierror.Error
 
-	toDelete := make(map[string]RulePair, len(h.rules))
+	toDelete := make(map[firewall.RuleID]RulePair, len(h.rules))
 	for id, r := range h.rules {
 		toDelete[id] = r
 	}
@@ -59,6 +59,10 @@ func (h *Manager) Update(forwardRules []firewall.ForwardRule) error {
 			mErr = multierror.Append(mErr, fmt.Errorf("add forward rule '%s': %v", fwdRule.String(), err))
 			continue
 		}
+		if rule == nil {
+			mErr = multierror.Append(mErr, fmt.Errorf("add forward rule '%s': backend returned no rule", fwdRule.String()))
+			continue
+		}
 		log.Infof("forward rule has been added '%s'", fwdRule)
 		h.rules[id] = RulePair{
 			ForwardRule: fwdRule,
@@ -90,7 +94,7 @@ func (h *Manager) Close() error {
 		}
 	}
 
-	h.rules = make(map[string]RulePair)
+	h.rules = make(map[firewall.RuleID]RulePair)
 	return nberrors.FormatErrorOrNil(mErr)
 }
 

client/internal/ingressgw/manager_test.go

@@ -14,11 +14,11 @@ var (
 )
 
 type MocFwRule struct {
-	id string
+	id firewall.RuleID
 }
 
-func (m *MocFwRule) ID() string {
-	return string(m.id)
+func (m *MocFwRule) ID() firewall.RuleID {
+	return m.id
 }
 
 type MockDNATFirewall struct {

client/internal/ipcauth/identity.go

@@ -91,6 +91,19 @@ func (i Identity) IsPrivileged() bool {
 	return slices.Contains(i.Groups, sidAdministrators)
 }
 
+// SameUser reports whether two identities are the same local principal. Only
+// the account is compared: the group set and the elevation flag describe what a
+// token may do, not who it belongs to. A SID on either side decides the
+// comparison, so a Windows principal never matches a Unix one on the UID both
+// happen to leave at zero. The zero Identity carries uid 0, so callers must
+// establish that both identities are real before the answer means anything.
+func (i Identity) SameUser(other Identity) bool {
+	if i.SID != "" || other.SID != "" {
+		return i.SID == other.SID
+	}
+	return i.UID == other.UID
+}
+
 // String renders the identity for audit logs and denial messages.
 func (i Identity) String() string {
 	if i.IsWindows() {

client/internal/ipcauth/identity_sameuser_test.go

@@ -0,0 +1,66 @@
+package ipcauth
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestIdentitySameUser(t *testing.T) {
+	tests := []struct {
+		name string
+		a    Identity
+		b    Identity
+		want bool
+	}{
+		{
+			name: "same uid",
+			a:    Identity{UID: 1000, GID: 1000},
+			b:    Identity{UID: 1000, GID: 1000},
+			want: true,
+		},
+		{
+			name: "same uid, different gid and pid still the same user",
+			a:    Identity{UID: 1000, GID: 1000, PID: 11},
+			b:    Identity{UID: 1000, GID: 27, PID: 22},
+			want: true,
+		},
+		{
+			name: "different uid",
+			a:    Identity{UID: 1000},
+			b:    Identity{UID: 1001},
+			want: false,
+		},
+		{
+			name: "same sid",
+			a:    Identity{SID: "S-1-5-21-1-2-3-1001"},
+			b:    Identity{SID: "S-1-5-21-1-2-3-1001"},
+			want: true,
+		},
+		{
+			name: "same sid, elevation and groups differ",
+			a:    Identity{SID: "S-1-5-21-1-2-3-1001", Elevated: true, Groups: []string{sidAdministrators}},
+			b:    Identity{SID: "S-1-5-21-1-2-3-1001"},
+			want: true,
+		},
+		{
+			name: "different sid",
+			a:    Identity{SID: "S-1-5-21-1-2-3-1001"},
+			b:    Identity{SID: "S-1-5-21-1-2-3-1002"},
+			want: false,
+		},
+		{
+			name: "a windows principal is never a unix one",
+			a:    Identity{SID: "S-1-5-18"},
+			b:    Identity{UID: 0},
+			want: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			assert.Equal(t, tt.want, tt.a.SameUser(tt.b))
+			assert.Equal(t, tt.want, tt.b.SameUser(tt.a), "SameUser must be symmetric")
+		})
+	}
+}

client/internal/message_convert.go

@@ -10,21 +10,6 @@ import (
 	mgmProto "github.com/netbirdio/netbird/shared/management/proto"
 )
 
-func convertToFirewallProtocol(protocol mgmProto.RuleProtocol) (firewallManager.Protocol, error) {
-	switch protocol {
-	case mgmProto.RuleProtocol_TCP:
-		return firewallManager.ProtocolTCP, nil
-	case mgmProto.RuleProtocol_UDP:
-		return firewallManager.ProtocolUDP, nil
-	case mgmProto.RuleProtocol_ICMP:
-		return firewallManager.ProtocolICMP, nil
-	case mgmProto.RuleProtocol_ALL:
-		return firewallManager.ProtocolALL, nil
-	default:
-		return "", fmt.Errorf("invalid protocol type: %s", protocol.String())
-	}
-}
-
 func convertPortInfo(portInfo *mgmProto.PortInfo) (*firewallManager.Port, error) {
 	if portInfo == nil {
 		return nil, errors.New("portInfo cannot be nil")

client/internal/metrics/infra/README.md

@@ -32,13 +32,24 @@ Clients do not talk to InfluxDB directly. An ingest server sits between clients
 ```text
 Client ──POST──▶ Ingest Server (:8087) ──▶ InfluxDB (internal)
                   │
+                  ├─ Checks the X-Peer-ID header format
                   ├─ Validates line protocol
                   ├─ Allowlists measurements, fields, and tags
                   ├─ Rejects out-of-bound values
                   └─ Serves remote config at /config
 ```
 
-- **No secret/token-based client auth** — the ingest server holds the InfluxDB token server-side. Clients must send a hashed peer ID via `X-Peer-ID` header.
+- **Intentionally unauthenticated** — the endpoint receives obfuscated telemetry from
+  the peers of both cloud and self-hosted deployments. For a self-hosted peer there is
+  no shared trust anchor with this server, so there is nothing to authenticate against.
+- **`X-Peer-ID` is a correlation tag, not a credential** — it carries the obfuscated
+  peer identifier so samples from one peer can be grouped. The server only checks that
+  the header is well-formed (16 hex chars); a malformed value is rejected with
+  `400 Bad Request`, not `401`. Any well-formed value is accepted by design, and the
+  header must not be relied on for access control. The header itself is not forwarded
+  to InfluxDB — the stored `peer_id` tag comes from the request body and is constrained
+  only by the tag allowlist and the maximum tag value length.
+- **The InfluxDB token stays server-side** — clients never hold a write credential.
 - **InfluxDB is not exposed** — only accessible within the docker network
 - Source: `ingest/main.go`
 
@@ -61,7 +72,7 @@ Tags:
 - `version`: NetBird version string
 - `os`: Operating system (linux, darwin, windows, android, ios, etc.)
 - `arch`: CPU architecture (amd64, arm64, etc.)
-- `peer_id`: anonymised peer identifier (truncated SHA-256 of the WireGuard public key)
+- `peer_id`: obfuscated peer identifier (truncated SHA-256 of the WireGuard public key)
 - `connection_pair_id`: deterministic identifier for the peer pair, identical on both sides
 
 **Note:** `SignalingReceived` is set when the first offer or answer arrives from the remote peer (in both initial and reconnection paths). It excludes the potentially unbounded wait for the remote peer to come online.
@@ -195,7 +206,7 @@ docker compose up -d
 ```
 
 This starts:
-- **Ingest server** on http://localhost:8087 — accepts client metrics (requires `X-Peer-ID` header, no secret/token auth)
+- **Ingest server** on http://localhost:8087 — accepts client metrics (unauthenticated by design; expects a well-formed `X-Peer-ID` correlation tag)
 - **InfluxDB** — internal only, not exposed to host
 - **Grafana** on http://localhost:3001
 

client/internal/metrics/infra/ingest/main.go

@@ -22,6 +22,11 @@ const (
 	maxDurationSeconds = 86400.0          // reject any duration field > 24 hours
 	peerIDLength       = 16               // truncated SHA-256: 8 bytes = 16 hex chars
 	maxTagValueLength  = 64               // reject tag values longer than this
+	readTimeout        = 30 * time.Second // must fit reading a compressed body up to maxBodySize
+	writeTimeout       = 60 * time.Second // must exceed the upstream client timeout below
+	idleTimeout        = 120 * time.Second
+	readHeaderTimeout  = 10 * time.Second
+	maxHeaderBytes     = 1 << 20 // 1 MB
 )
 
 type measurementSpec struct {
@@ -124,8 +129,17 @@ func main() {
 		fmt.Fprint(w, "ok") //nolint:errcheck
 	})
 
+	srv := &http.Server{
+		Addr:              listenAddr,
+		ReadTimeout:       readTimeout,
+		ReadHeaderTimeout: readHeaderTimeout,
+		WriteTimeout:      writeTimeout,
+		IdleTimeout:       idleTimeout,
+		MaxHeaderBytes:    maxHeaderBytes,
+	}
+
 	log.Printf("ingest server listening on %s, forwarding to %s", listenAddr, influxURL)
-	if err := http.ListenAndServe(listenAddr, nil); err != nil { //nolint:gosec
+	if err := srv.ListenAndServe(); err != nil {
 		log.Fatal(err)
 	}
 }
@@ -137,8 +151,8 @@ func handleIngest(client *http.Client, influxURL, influxToken string) http.Handl
 			return
 		}
 
-		if err := validateAuth(r); err != nil {
-			http.Error(w, err.Error(), http.StatusUnauthorized)
+		if err := validatePeerIDFormat(r); err != nil {
+			http.Error(w, err.Error(), http.StatusBadRequest)
 			return
 		}
 
@@ -187,8 +201,13 @@ func forwardToInflux(w http.ResponseWriter, r *http.Request, client *http.Client
 	io.Copy(w, resp.Body) //nolint:errcheck
 }
 
-// validateAuth checks that the X-Peer-ID header contains a valid hashed peer ID.
-func validateAuth(r *http.Request) error {
+// validatePeerIDFormat checks the shape of the X-Peer-ID header. The header is a
+// correlation tag, not a credential: this endpoint is intentionally
+// unauthenticated so that peers of self-hosted deployments, for which no shared
+// trust anchor exists, can report obfuscated telemetry. The header is not forwarded
+// to InfluxDB, so this check does not bound the stored peer_id tag; it only rejects
+// a malformed header as a bad request rather than an auth failure.
+func validatePeerIDFormat(r *http.Request) error {
 	peerID := r.Header.Get("X-Peer-ID")
 	if peerID == "" {
 		return fmt.Errorf("missing X-Peer-ID header")

client/internal/metrics/infra/ingest/main_test.go

@@ -94,7 +94,7 @@ func TestValidateLineProtocol_RejectsOnBadLine(t *testing.T) {
 	require.Error(t, err)
 }
 
-func TestValidateAuth(t *testing.T) {
+func TestValidatePeerIDFormat(t *testing.T) {
 	tests := []struct {
 		name    string
 		peerID  string
@@ -113,7 +113,7 @@ func TestValidateAuth(t *testing.T) {
 			if tt.peerID != "" {
 				r.Header.Set("X-Peer-ID", tt.peerID)
 			}
-			err := validateAuth(r)
+			err := validatePeerIDFormat(r)
 			if tt.wantErr {
 				require.Error(t, err)
 			} else {

client/internal/routemanager/manager.go

@@ -8,6 +8,7 @@ import (
 	"net/netip"
 	"net/url"
 	"runtime"
+	"slices"
 	"sort"
 	"strings"
 	"sync"
@@ -472,27 +473,13 @@ func (m *DefaultManager) CurrentRouteRange() []string {
 	m.mux.Lock()
 	defer m.mux.Unlock()
 
-	if m.disableClientRoutes {
-		return nil
-	}
-
-	filtered := m.routeSelector.FilterSelectedExitNodes(m.clientRoutes)
-	var nets []string
-	for _, routes := range filtered {
-		for _, r := range routes {
-			if r.IsDynamic() {
-				continue
-			}
-			nets = append(nets, r.NetString())
-		}
-	}
-
-	if m.fakeIPManager != nil {
-		nets = append(nets, m.fakeIPManager.GetFakeIPBlock().String(), m.fakeIPManager.GetFakeIPv6Block().String())
+	nets := m.overlayNetworks()
+	if !m.disableClientRoutes {
+		nets = append(nets, m.clientRouteRange()...)
 	}
 
 	sort.Strings(nets)
-	return nets
+	return slices.Compact(nets)
 }
 
 // GetRouteSelector returns the route selector
@@ -856,6 +843,42 @@ func (m *DefaultManager) logExitNodeUpdate(info exitNodeInfo, preferred route.Ne
 		len(info.allIDs), preferred, len(info.userSelected), len(info.userDeselected), len(info.selectedByManagement))
 }
 
+// overlayNetworks returns the v4 and v6 overlay networks of the WireGuard interface, each only when it is set.
+func (m *DefaultManager) overlayNetworks() []string {
+	if m.wgInterface == nil {
+		return nil
+	}
+
+	addr := m.wgInterface.Address()
+	var nets []string
+	if addr.Network.IsValid() {
+		nets = append(nets, addr.Network.String())
+	}
+	if addr.IPv6Net.IsValid() {
+		nets = append(nets, addr.IPv6Net.String())
+	}
+	return nets
+}
+
+// clientRouteRange returns the static client route networks of the selected exit nodes together with the fake IP blocks.
+func (m *DefaultManager) clientRouteRange() []string {
+	filtered := m.routeSelector.FilterSelectedExitNodes(m.clientRoutes)
+	var nets []string
+	for _, routes := range filtered {
+		for _, r := range routes {
+			if r.IsDynamic() {
+				continue
+			}
+			nets = append(nets, r.NetString())
+		}
+	}
+
+	if m.fakeIPManager != nil {
+		nets = append(nets, m.fakeIPManager.GetFakeIPBlock().String(), m.fakeIPManager.GetFakeIPv6Block().String())
+	}
+	return nets
+}
+
 // minNetID returns the lexicographically smallest NetID, for a deterministic
 // default pick that stays stable across restarts.
 func minNetID(ids []route.NetID) route.NetID {

client/internal/routemanager/notifier/notifier_android.go

@@ -4,8 +4,6 @@ package notifier
 
 import (
 	"net/netip"
-	"slices"
-	"sort"
 	"sync"
 
 	"github.com/netbirdio/netbird/client/internal/listener"
@@ -75,19 +73,3 @@ func (n *Notifier) notifyLocked() {
 func (n *Notifier) Close() {
 	// unused
 }
-
-func routesToStrings(routes []*route.Route) []string {
-	nets := make([]string, 0, len(routes))
-	for _, r := range routes {
-		nets = append(nets, r.NetString())
-	}
-	return nets
-}
-
-func hasRouteDiff(a []*route.Route, b []*route.Route) bool {
-	as := routesToStrings(a)
-	bs := routesToStrings(b)
-	sort.Strings(as)
-	sort.Strings(bs)
-	return !slices.Equal(as, bs)
-}

client/internal/routemanager/notifier/route_diff.go

@@ -0,0 +1,27 @@
+package notifier
+
+import (
+	"slices"
+	"sort"
+
+	"github.com/netbirdio/netbird/route"
+)
+
+// routePrefixes returns the distinct prefixes a route set covers, sorted.
+// Duplicates are dropped deliberately: an HA group hands us one route per
+// peer serving the same prefix, and the platform is given the prefix, not the
+// candidates. Counting them would report a change every time a peer joins or
+// leaves a group, and on Android each report renews the TUN.
+func routePrefixes(routes []*route.Route) []string {
+	nets := make([]string, 0, len(routes))
+	for _, r := range routes {
+		nets = append(nets, r.NetString())
+	}
+	sort.Strings(nets)
+	return slices.Compact(nets)
+}
+
+// hasRouteDiff reports whether the prefixes the two route sets cover differ.
+func hasRouteDiff(a []*route.Route, b []*route.Route) bool {
+	return !slices.Equal(routePrefixes(a), routePrefixes(b))
+}

client/internal/routemanager/notifier/route_diff_test.go

@@ -0,0 +1,88 @@
+package notifier
+
+import (
+	"net/netip"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/netbirdio/netbird/route"
+)
+
+func routeFor(id route.ID, prefix string) *route.Route {
+	return &route.Route{
+		ID:      id,
+		NetID:   "net",
+		Network: netip.MustParsePrefix(prefix),
+	}
+}
+
+// TestHasRouteDiff_IgnoresHACandidateCount is the reason the comparison
+// deduplicates. Every notification renews the TUN, and a renewed TUN
+// invalidates the sockets the embedded servers are listening on, so a peer
+// joining or leaving an HA group must not count as a route change when the
+// prefixes the TUN carries are identical.
+func TestHasRouteDiff_IgnoresHACandidateCount(t *testing.T) {
+	onePeer := []*route.Route{routeFor("a", "10.0.0.0/24")}
+	twoPeers := []*route.Route{
+		routeFor("a", "10.0.0.0/24"),
+		routeFor("b", "10.0.0.0/24"),
+	}
+
+	assert.False(t, hasRouteDiff(onePeer, twoPeers),
+		"a second peer serving the same prefix is not a route change")
+	assert.False(t, hasRouteDiff(twoPeers, onePeer),
+		"losing one of two peers serving the same prefix is not a route change")
+}
+
+func TestHasRouteDiff_ReportsRealChanges(t *testing.T) {
+	tests := []struct {
+		name string
+		a    []*route.Route
+		b    []*route.Route
+		want bool
+	}{
+		{
+			name: "added prefix",
+			a:    []*route.Route{routeFor("a", "10.0.0.0/24")},
+			b:    []*route.Route{routeFor("a", "10.0.0.0/24"), routeFor("b", "10.0.1.0/24")},
+			want: true,
+		},
+		{
+			name: "removed prefix",
+			a:    []*route.Route{routeFor("a", "10.0.0.0/24"), routeFor("b", "10.0.1.0/24")},
+			b:    []*route.Route{routeFor("a", "10.0.0.0/24")},
+			want: true,
+		},
+		{
+			name: "replaced prefix",
+			a:    []*route.Route{routeFor("a", "10.0.0.0/24")},
+			b:    []*route.Route{routeFor("a", "10.0.1.0/24")},
+			want: true,
+		},
+		{
+			name: "same prefix, different order",
+			a:    []*route.Route{routeFor("a", "10.0.1.0/24"), routeFor("b", "10.0.0.0/24")},
+			b:    []*route.Route{routeFor("b", "10.0.0.0/24"), routeFor("a", "10.0.1.0/24")},
+			want: false,
+		},
+		{
+			name: "all routes gone",
+			a:    []*route.Route{routeFor("a", "10.0.0.0/24")},
+			b:    nil,
+			want: true,
+		},
+		{
+			name: "both empty",
+			a:    nil,
+			b:    nil,
+			want: false,
+		},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			assert.Equal(t, tc.want, hasRouteDiff(tc.a, tc.b),
+				"route diff for %s", tc.name)
+		})
+	}
+}

client/internal/routemanager/reconcile_test.go

@@ -17,11 +17,12 @@ import (
 	"github.com/netbirdio/netbird/client/internal/routemanager/refcounter"
 )
 
-// reconcileWGMock is a minimal iface.WGIface that only records AddAllowedIP calls; every other
-// method is an inert stub because ReconcilePeerAllowedIPs exercises none of them.
+// reconcileWGMock is a minimal iface.WGIface that records AddAllowedIP calls and reports the
+// configured address; every other method is an inert stub because the tests exercise none of them.
 type reconcileWGMock struct {
 	mu   sync.Mutex
 	adds map[string][]netip.Prefix
+	addr wgaddr.Address
 }
 
 func (m *reconcileWGMock) AddAllowedIP(peerKey string, allowedIP netip.Prefix) error {
@@ -42,7 +43,7 @@ func (m *reconcileWGMock) added(peerKey string) []netip.Prefix {
 
 func (m *reconcileWGMock) RemoveAllowedIP(string, netip.Prefix) error { return nil }
 func (m *reconcileWGMock) Name() string                               { return "utun-test" }
-func (m *reconcileWGMock) Address() wgaddr.Address                    { return wgaddr.Address{} }
+func (m *reconcileWGMock) Address() wgaddr.Address                    { return m.addr }
 func (m *reconcileWGMock) ToInterface() *net.Interface                { return nil }
 func (m *reconcileWGMock) IsUserspaceBind() bool                      { return false }
 func (m *reconcileWGMock) GetFilter() device.PacketFilter             { return nil }

client/internal/routemanager/route_range_test.go

@@ -0,0 +1,95 @@
+//go:build !windows
+
+package routemanager
+
+import (
+	"net/netip"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/netbirdio/netbird/client/iface/wgaddr"
+	"github.com/netbirdio/netbird/client/internal/routeselector"
+	"github.com/netbirdio/netbird/route"
+)
+
+func TestCurrentRouteRange_OverlayNetworkWithClientRoutesDisabled(t *testing.T) {
+	m := &DefaultManager{
+		wgInterface:         &reconcileWGMock{addr: wgaddr.MustParseWGAddress("100.91.96.107/16")},
+		disableClientRoutes: true,
+	}
+
+	assert.Equal(t, []string{"100.91.0.0/16"}, m.CurrentRouteRange(), "overlay network must be routed even when client routes are disabled")
+}
+
+func TestCurrentRouteRange_OverlayNetworksAndClientRoutes(t *testing.T) {
+	addr := wgaddr.MustParseWGAddress("100.91.96.107/16")
+	addr.IPv6 = netip.MustParseAddr("fd00:1234::1")
+	addr.IPv6Net = netip.MustParsePrefix("fd00:1234::/64")
+
+	static := &route.Route{ID: "static", NetID: "lan", Network: netip.MustParsePrefix("192.168.50.0/24"), NetworkType: route.IPv4Network}
+	dynamic := &route.Route{ID: "dynamic", NetID: "dyn", NetworkType: route.DomainNetwork}
+
+	m := &DefaultManager{
+		wgInterface:   &reconcileWGMock{addr: addr},
+		routeSelector: routeselector.NewRouteSelector(),
+		clientRoutes: route.HAMap{
+			static.GetHAUniqueID():  {static},
+			dynamic.GetHAUniqueID(): {dynamic},
+		},
+	}
+
+	assert.Equal(t, []string{"100.91.0.0/16", "192.168.50.0/24", "fd00:1234::/64"}, m.CurrentRouteRange(), "overlay networks and static client routes must be listed, dynamic routes skipped")
+}
+
+func TestCurrentRouteRange_NoInterfaceAddress(t *testing.T) {
+	m := &DefaultManager{
+		wgInterface:         &reconcileWGMock{},
+		disableClientRoutes: true,
+	}
+
+	assert.Empty(t, m.CurrentRouteRange(), "an unset interface address must not produce a route entry")
+}
+
+func TestCurrentRouteRange_IPv6WithoutIPv4Network(t *testing.T) {
+	addr := wgaddr.Address{
+		IPv6:    netip.MustParseAddr("fd00:1234::1"),
+		IPv6Net: netip.MustParsePrefix("fd00:1234::/64"),
+	}
+	m := &DefaultManager{
+		wgInterface:         &reconcileWGMock{addr: addr},
+		disableClientRoutes: true,
+	}
+
+	assert.Equal(t, []string{"fd00:1234::/64"}, m.CurrentRouteRange(), "a v6 overlay network must not depend on a v4 network being set")
+}
+
+func TestCurrentRouteRange_IPv6AddressWithoutNetwork(t *testing.T) {
+	addr := wgaddr.MustParseWGAddress("100.91.96.107/16")
+	addr.IPv6 = netip.MustParseAddr("fd00:1234::1")
+
+	m := &DefaultManager{
+		wgInterface:         &reconcileWGMock{addr: addr},
+		disableClientRoutes: true,
+	}
+
+	assert.Equal(t, []string{"100.91.0.0/16"}, m.CurrentRouteRange(), "a v6 address without a network must not produce a route entry")
+}
+
+func TestCurrentRouteRange_DeduplicatesPrefixes(t *testing.T) {
+	// Two HA peers serve the same prefix, and a client route announces the overlay network itself.
+	haPeerA := &route.Route{ID: "ha-a", NetID: "lan", Peer: "peer-a", Network: netip.MustParsePrefix("192.168.50.0/24"), NetworkType: route.IPv4Network}
+	haPeerB := &route.Route{ID: "ha-b", NetID: "lan", Peer: "peer-b", Network: netip.MustParsePrefix("192.168.50.0/24"), NetworkType: route.IPv4Network}
+	overlay := &route.Route{ID: "overlay", NetID: "overlay", Network: netip.MustParsePrefix("100.91.0.0/16"), NetworkType: route.IPv4Network}
+
+	m := &DefaultManager{
+		wgInterface:   &reconcileWGMock{addr: wgaddr.MustParseWGAddress("100.91.96.107/16")},
+		routeSelector: routeselector.NewRouteSelector(),
+		clientRoutes: route.HAMap{
+			haPeerA.GetHAUniqueID(): {haPeerA, haPeerB},
+			overlay.GetHAUniqueID(): {overlay},
+		},
+	}
+
+	assert.Equal(t, []string{"100.91.0.0/16", "192.168.50.0/24"}, m.CurrentRouteRange(), "every prefix must be listed once regardless of how many routes carry it")
+}

client/internal/routemanager/server/server.go

@@ -135,6 +135,14 @@ func (r *Router) CleanUp() {
 		}
 	}
 
+	// Give back the routing reference taken in UpdateRoutes, after the routes
+	// are gone as above. Without this the sysctls enabling it changed (IPv6
+	// forwarding and the accept_ra values that keep RA handling alive next to
+	// it) stay applied once the client stops.
+	if err := r.firewall.DisableRouting(); err != nil {
+		log.Errorf("Failed to disable routing: %v", err)
+	}
+
 	r.statusRecorder.CleanLocalPeerStateRoutes()
 }
 

client/internal/routemanager/server/server_test.go

@@ -0,0 +1,66 @@
+package server
+
+import (
+	"context"
+	"net/netip"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	firewall "github.com/netbirdio/netbird/client/firewall/manager"
+	"github.com/netbirdio/netbird/client/internal/peer"
+	"github.com/netbirdio/netbird/route"
+)
+
+// routingFirewall records the routing lifecycle calls the router makes. The
+// embedded interface covers the methods this test never reaches.
+type routingFirewall struct {
+	firewall.Manager
+
+	removed  []firewall.RouterPair
+	enabled  int
+	disabled int
+}
+
+func (f *routingFirewall) RemoveNatRule(pair firewall.RouterPair) error {
+	f.removed = append(f.removed, pair)
+	return nil
+}
+
+func (f *routingFirewall) EnableRouting() error {
+	f.enabled++
+	return nil
+}
+
+func (f *routingFirewall) DisableRouting() error {
+	f.disabled++
+	return nil
+}
+
+// TestRouterCleanUpReleasesRouting covers the shutdown path: the router holds a
+// routing reference for as long as it serves routes, and CleanUp has to give it
+// back. Without that the sysctls the reference enabled (IPv6 forwarding and the
+// accept_ra values that keep RA handling working alongside it) stay applied
+// after the client stops, leaving the host configured as a router.
+func TestRouterCleanUpReleasesRouting(t *testing.T) {
+	fw := &routingFirewall{}
+	r := &Router{
+		ctx:            context.Background(),
+		firewall:       fw,
+		statusRecorder: peer.NewRecorder("https://mgm"),
+		routes: map[route.ID]*route.Route{
+			"route-1": {
+				ID:          "route-1",
+				Network:     netip.MustParsePrefix("192.168.55.0/24"),
+				NetworkType: route.IPv4Network,
+				Masquerade:  true,
+			},
+		},
+	}
+
+	r.CleanUp()
+
+	require.Len(t, fw.removed, 1, "the route's NAT rule must be removed")
+	assert.Equal(t, 1, fw.disabled, "CleanUp must release the routing reference")
+}