Add IPv6 overlay address support to client interface and engine

client/internal/auth/auth.go

@@ -345,6 +345,7 @@ func (a *Auth) setSystemInfoFlags(info *system.Info) {
 		a.config.DisableFirewall,
 		a.config.BlockLANAccess,
 		a.config.BlockInbound,
+		a.config.DisableIPv6,
 		a.config.LazyConnectionEnabled,
 		a.config.EnableSSHRoot,
 		a.config.EnableSSHSFTP,

client/internal/connect.go

@@ -14,10 +14,13 @@ import (
 
 	"github.com/cenkalti/backoff/v4"
 	log "github.com/sirupsen/logrus"
+
 	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
 	"google.golang.org/grpc/codes"
 	gstatus "google.golang.org/grpc/status"
 
+	"github.com/netbirdio/netbird/client/iface/wgaddr"
+
 	"github.com/netbirdio/netbird/client/iface"
 	"github.com/netbirdio/netbird/client/iface/device"
 	"github.com/netbirdio/netbird/client/iface/netstack"
@@ -520,9 +523,20 @@ func createEngineConfig(key wgtypes.Key, config *profilemanager.Config, peerConf
 	if config.NetworkMonitor != nil {
 		nm = *config.NetworkMonitor
 	}
+	wgAddr, err := wgaddr.ParseWGAddress(peerConfig.Address)
+	if err != nil {
+		return nil, fmt.Errorf("parse overlay address %q: %w", peerConfig.Address, err)
+	}
+
+	if !config.DisableIPv6 {
+		if err := wgAddr.SetIPv6FromCompact(peerConfig.GetAddressV6()); err != nil {
+			log.Warnf(err.Error())
+		}
+	}
+
 	engineConf := &EngineConfig{
 		WgIfaceName:                   config.WgIface,
-		WgAddr:                        peerConfig.Address,
+		WgAddr:                        wgAddr,
 		IFaceBlackList:                config.IFaceBlackList,
 		DisableIPv6Discovery:          config.DisableIPv6Discovery,
 		WgPrivateKey:                  key,
@@ -547,6 +561,7 @@ func createEngineConfig(key wgtypes.Key, config *profilemanager.Config, peerConf
 		DisableFirewall:     config.DisableFirewall,
 		BlockLANAccess:      config.BlockLANAccess,
 		BlockInbound:        config.BlockInbound,
+		DisableIPv6:         config.DisableIPv6,
 
 		LazyConnectionEnabled: config.LazyConnectionEnabled,
 
@@ -627,6 +642,7 @@ func loginToManagement(ctx context.Context, client mgm.Client, pubSSHKey []byte,
 		config.DisableFirewall,
 		config.BlockLANAccess,
 		config.BlockInbound,
+		config.DisableIPv6,
 		config.LazyConnectionEnabled,
 		config.EnableSSHRoot,
 		config.EnableSSHSFTP,

client/internal/debug/debug.go

@@ -522,6 +522,7 @@ func (g *BundleGenerator) addCommonConfigFields(configContent *strings.Builder)
 	configContent.WriteString(fmt.Sprintf("DisableFirewall: %v\n", g.internalConfig.DisableFirewall))
 	configContent.WriteString(fmt.Sprintf("BlockLANAccess: %v\n", g.internalConfig.BlockLANAccess))
 	configContent.WriteString(fmt.Sprintf("BlockInbound: %v\n", g.internalConfig.BlockInbound))
+	configContent.WriteString(fmt.Sprintf("DisableIPv6: %v\n", g.internalConfig.DisableIPv6))
 
 	if g.internalConfig.DisableNotifications != nil {
 		configContent.WriteString(fmt.Sprintf("DisableNotifications: %v\n", *g.internalConfig.DisableNotifications))

client/internal/dns/server_test.go

@@ -347,7 +347,7 @@ func TestUpdateDNSServer(t *testing.T) {
 
 			opts := iface.WGIFaceOpts{
 				IFaceName:    fmt.Sprintf("utun230%d", n),
-				Address:      fmt.Sprintf("100.66.100.%d/32", n+1),
+				Address:      wgaddr.MustParseWGAddress(fmt.Sprintf("100.66.100.%d/32", n+1)),
 				WGPort:       33100,
 				WGPrivKey:    privKey.String(),
 				MTU:          iface.DefaultMTU,
@@ -448,7 +448,7 @@ func TestDNSFakeResolverHandleUpdates(t *testing.T) {
 	privKey, _ := wgtypes.GeneratePrivateKey()
 	opts := iface.WGIFaceOpts{
 		IFaceName:    "utun2301",
-		Address:      "100.66.100.1/32",
+		Address:      wgaddr.MustParseWGAddress("100.66.100.1/32"),
 		WGPort:       33100,
 		WGPrivKey:    privKey.String(),
 		MTU:          iface.DefaultMTU,
@@ -929,7 +929,7 @@ func createWgInterfaceWithBind(t *testing.T) (*iface.WGIface, error) {
 
 	opts := iface.WGIFaceOpts{
 		IFaceName:    "utun2301",
-		Address:      "100.66.100.2/24",
+		Address:      wgaddr.MustParseWGAddress("100.66.100.2/24"),
 		WGPort:       33100,
 		WGPrivKey:    privKey.String(),
 		MTU:          iface.DefaultMTU,

client/internal/engine.go

@@ -28,6 +28,8 @@ import (
 	"github.com/netbirdio/netbird/client/firewall"
 	firewallManager "github.com/netbirdio/netbird/client/firewall/manager"
 	"github.com/netbirdio/netbird/client/iface"
+	"github.com/netbirdio/netbird/client/iface/wgaddr"
+	"github.com/netbirdio/netbird/shared/netiputil"
 	"github.com/netbirdio/netbird/client/iface/device"
 	nbnetstack "github.com/netbirdio/netbird/client/iface/netstack"
 	"github.com/netbirdio/netbird/client/iface/udpmux"
@@ -84,8 +86,9 @@ type EngineConfig struct {
 	WgPort      int
 	WgIfaceName string
 
-	// WgAddr is a Wireguard local address (Netbird Network IP)
-	WgAddr string
+	// WgAddr is the Wireguard local address (Netbird Network IP).
+	// Contains both v4 and optional v6 overlay addresses.
+	WgAddr wgaddr.Address
 
 	// WgPrivateKey is a Wireguard private key of our peer (it MUST never leave the machine)
 	WgPrivateKey wgtypes.Key
@@ -130,6 +133,7 @@ type EngineConfig struct {
 	DisableFirewall     bool
 	BlockLANAccess      bool
 	BlockInbound        bool
+	DisableIPv6         bool
 
 	LazyConnectionEnabled bool
 
@@ -703,7 +707,7 @@ func (e *Engine) modifyPeers(peersUpdate []*mgmProto.RemotePeerConfig) error {
 		if !ok {
 			continue
 		}
-		if !compareNetIPLists(allowedIPs, p.GetAllowedIps()) {
+		if !compareNetIPLists(allowedIPs, e.filterAllowedIPs(p.GetAllowedIps())) {
 			modified = append(modified, p)
 			continue
 		}
@@ -977,6 +981,7 @@ func (e *Engine) updateChecksIfNew(checks []*mgmProto.Checks) error {
 		e.config.DisableFirewall,
 		e.config.BlockLANAccess,
 		e.config.BlockInbound,
+		e.config.DisableIPv6,
 		e.config.LazyConnectionEnabled,
 		e.config.EnableSSHRoot,
 		e.config.EnableSSHSFTP,
@@ -1004,6 +1009,13 @@ func (e *Engine) updateConfig(conf *mgmProto.PeerConfig) error {
 		return ErrResetConnection
 	}
 
+	if !e.config.DisableIPv6 && e.hasIPv6Changed(conf) {
+		log.Infof("peer IPv6 address changed, restarting client")
+		_ = CtxGetState(e.ctx).Wrap(ErrResetConnection)
+		e.clientCancel()
+		return ErrResetConnection
+	}
+
 	if conf.GetSshConfig() != nil {
 		if err := e.updateSSH(conf.GetSshConfig()); err != nil {
 			log.Warnf("failed handling SSH server setup: %v", err)
@@ -1012,6 +1024,7 @@ func (e *Engine) updateConfig(conf *mgmProto.PeerConfig) error {
 
 	state := e.statusRecorder.GetLocalPeerState()
 	state.IP = e.wgInterface.Address().String()
+	state.IPv6 = e.wgInterface.Address().IPv6String()
 	state.PubKey = e.config.WgPrivateKey.PublicKey().String()
 	state.KernelInterface = !e.wgInterface.IsUserspaceBind()
 	state.FQDN = conf.GetFqdn()
@@ -1020,6 +1033,26 @@ func (e *Engine) updateConfig(conf *mgmProto.PeerConfig) error {
 
 	return nil
 }
+
+// hasIPv6Changed reports whether the IPv6 overlay address in the peer config
+// differs from the current interface address (added, removed, or changed).
+func (e *Engine) hasIPv6Changed(conf *mgmProto.PeerConfig) bool {
+	current := e.wgInterface.Address()
+	raw := conf.GetAddressV6()
+
+	if len(raw) == 0 {
+		return current.HasIPv6()
+	}
+
+	addr, err := netiputil.DecodeAddr(raw)
+	if err != nil {
+		log.Warnf("decode v6 overlay address: %v", err)
+		return false
+	}
+
+	return !current.HasIPv6() || current.IPv6 != addr
+}
+
 func (e *Engine) receiveJobEvents() {
 	e.jobExecutorWG.Add(1)
 	go func() {
@@ -1117,6 +1150,7 @@ func (e *Engine) receiveManagementEvents() {
 			e.config.DisableFirewall,
 			e.config.BlockLANAccess,
 			e.config.BlockInbound,
+			e.config.DisableIPv6,
 			e.config.LazyConnectionEnabled,
 			e.config.EnableSSHRoot,
 			e.config.EnableSSHSFTP,
@@ -1437,8 +1471,10 @@ func (e *Engine) updateOfflinePeers(offlinePeers []*mgmProto.RemotePeerConfig) {
 	replacement := make([]peer.State, len(offlinePeers))
 	for i, offlinePeer := range offlinePeers {
 		log.Debugf("added offline peer %s", offlinePeer.Fqdn)
+		v4, v6 := splitAllowedIPs(offlinePeer.GetAllowedIps(), e.wgInterface.Address().IPv6Net)
 		replacement[i] = peer.State{
-			IP:               strings.Join(offlinePeer.GetAllowedIps(), ","),
+			IP:               v4,
+			IPv6:             v6,
 			PubKey:           offlinePeer.GetWgPubKey(),
 			FQDN:             offlinePeer.GetFqdn(),
 			ConnStatus:       peer.StatusIdle,
@@ -1449,6 +1485,30 @@ func (e *Engine) updateOfflinePeers(offlinePeers []*mgmProto.RemotePeerConfig) {
 	e.statusRecorder.ReplaceOfflinePeers(replacement)
 }
 
+// splitAllowedIPs separates the peer's overlay v4 (/32) and v6 (/128) addresses
+// from a list of AllowedIPs CIDRs. The v6 address is only matched if it falls
+// within ourV6Net (the local overlay v6 subnet), to avoid confusing routed /128
+// prefixes with the peer's overlay address.
+func splitAllowedIPs(allowedIPs []string, ourV6Net netip.Prefix) (v4, v6 string) {
+	for _, cidr := range allowedIPs {
+		prefix, err := netip.ParsePrefix(cidr)
+		if err != nil {
+			log.Warnf("failed to parse AllowedIP %q: %v", cidr, err)
+			continue
+		}
+		switch {
+		case prefix.Addr().Is4() && prefix.Bits() == 32 && v4 == "":
+			v4 = prefix.Addr().String()
+		case prefix.Addr().Is6() && prefix.Bits() == 128 && ourV6Net.Contains(prefix.Addr()) && v6 == "":
+			v6 = prefix.Addr().String()
+		}
+		if v4 != "" && v6 != "" {
+			break
+		}
+	}
+	return
+}
+
 // addNewPeers adds peers that were not know before but arrived from the Management service with the update
 func (e *Engine) addNewPeers(peersUpdate []*mgmProto.RemotePeerConfig) error {
 	for _, p := range peersUpdate {
@@ -1474,6 +1534,9 @@ func (e *Engine) addNewPeer(peerConfig *mgmProto.RemotePeerConfig) error {
 			log.Errorf("failed to parse allowedIPS: %v", err)
 			return err
 		}
+		if allowedNetIP.Addr().Is6() && !e.wgInterface.Address().HasIPv6() {
+			continue
+		}
 		peerIPs = append(peerIPs, allowedNetIP)
 	}
 
@@ -1482,7 +1545,15 @@ func (e *Engine) addNewPeer(peerConfig *mgmProto.RemotePeerConfig) error {
 		return fmt.Errorf("create peer connection: %w", err)
 	}
 
-	err = e.statusRecorder.AddPeer(peerKey, peerConfig.Fqdn, peerIPs[0].Addr().String())
+	var peerIPv6 string
+	ourV6Net := e.wgInterface.Address().IPv6Net
+	for _, pip := range peerIPs {
+		if pip.Addr().Is6() && pip.Bits() == 128 && ourV6Net.Contains(pip.Addr()) {
+			peerIPv6 = pip.Addr().String()
+			break
+		}
+	}
+	err = e.statusRecorder.AddPeer(peerKey, peerConfig.Fqdn, peerIPs[0].Addr().String(), peerIPv6)
 	if err != nil {
 		log.Warnf("error adding peer %s to status recorder, got error: %v", peerKey, err)
 	}
@@ -1705,6 +1776,7 @@ func (e *Engine) readInitialSettings() ([]*route.Route, *nbdns.Config, bool, err
 		e.config.DisableFirewall,
 		e.config.BlockLANAccess,
 		e.config.BlockInbound,
+		e.config.DisableIPv6,
 		e.config.LazyConnectionEnabled,
 		e.config.EnableSSHRoot,
 		e.config.EnableSSHSFTP,
@@ -1760,7 +1832,8 @@ func (e *Engine) wgInterfaceCreate() (err error) {
 	case "android":
 		err = e.wgInterface.CreateOnAndroid(e.routeManager.InitialRouteRange(), e.dnsServer.DnsIP().String(), e.dnsServer.SearchDomains())
 	case "ios":
-		e.mobileDep.NetworkChangeListener.SetInterfaceIP(e.config.WgAddr)
+		e.mobileDep.NetworkChangeListener.SetInterfaceIP(e.config.WgAddr.String())
+		e.mobileDep.NetworkChangeListener.SetInterfaceIPv6(e.config.WgAddr.IPv6String())
 		err = e.wgInterface.Create()
 	default:
 		err = e.wgInterface.Create()
@@ -2269,6 +2342,24 @@ func getInterfacePrefixes() ([]netip.Prefix, error) {
 	return prefixes, nberrors.FormatErrorOrNil(merr)
 }
 
+// filterAllowedIPs strips IPv6 entries when the local interface has no v6 address.
+// This covers both the explicit --disable-ipv6 flag (v6 never assigned) and the
+// case where OS v6 assignment failed (ClearIPv6). Without this, WireGuard would
+// accept v6 traffic that the native firewall cannot filter.
+func (e *Engine) filterAllowedIPs(ips []string) []string {
+	if e.wgInterface.Address().HasIPv6() {
+		return ips
+	}
+	filtered := make([]string, 0, len(ips))
+	for _, s := range ips {
+		p, err := netip.ParsePrefix(s)
+		if err != nil || !p.Addr().Is6() {
+			filtered = append(filtered, s)
+		}
+	}
+	return filtered
+}
+
 // compareNetIPLists compares a list of netip.Prefix with a list of strings.
 // return true if both lists are equal, false otherwise.
 func compareNetIPLists(list1 []netip.Prefix, list2 []string) bool {

client/internal/engine_test.go

@@ -66,6 +66,7 @@ import (
 	mgmt "github.com/netbirdio/netbird/shared/management/client"
 	mgmtProto "github.com/netbirdio/netbird/shared/management/proto"
 	relayClient "github.com/netbirdio/netbird/shared/relay/client"
+	"github.com/netbirdio/netbird/shared/netiputil"
 	signal "github.com/netbirdio/netbird/shared/signal/client"
 	"github.com/netbirdio/netbird/shared/signal/proto"
 	signalServer "github.com/netbirdio/netbird/signal/server"
@@ -94,7 +95,7 @@ type MockWGIface struct {
 	AddressFunc                func() wgaddr.Address
 	ToInterfaceFunc            func() *net.Interface
 	UpFunc                     func() (*udpmux.UniversalUDPMuxDefault, error)
-	UpdateAddrFunc             func(newAddr string) error
+	UpdateAddrFunc             func(newAddr wgaddr.Address) error
 	UpdatePeerFunc             func(peerKey string, allowedIps []netip.Prefix, keepAlive time.Duration, endpoint *net.UDPAddr, preSharedKey *wgtypes.Key) error
 	RemovePeerFunc             func(peerKey string) error
 	AddAllowedIPFunc           func(peerKey string, allowedIP netip.Prefix) error
@@ -156,7 +157,7 @@ func (m *MockWGIface) Up() (*udpmux.UniversalUDPMuxDefault, error) {
 	return m.UpFunc()
 }
 
-func (m *MockWGIface) UpdateAddr(newAddr string) error {
+func (m *MockWGIface) UpdateAddr(newAddr wgaddr.Address) error {
 	return m.UpdateAddrFunc(newAddr)
 }
 
@@ -253,7 +254,7 @@ func TestEngine_SSH(t *testing.T) {
 		ctx, cancel,
 		&EngineConfig{
 			WgIfaceName:      "utun101",
-			WgAddr:           "100.64.0.1/24",
+			WgAddr:           wgaddr.MustParseWGAddress("100.64.0.1/24"),
 			WgPrivateKey:     key,
 			WgPort:           33100,
 			ServerSSHAllowed: true,
@@ -430,7 +431,7 @@ func TestEngine_UpdateNetworkMap(t *testing.T) {
 	relayMgr := relayClient.NewManager(ctx, nil, key.PublicKey().String(), iface.DefaultMTU)
 	engine := NewEngine(ctx, cancel, &EngineConfig{
 		WgIfaceName:  "utun102",
-		WgAddr:       "100.64.0.1/24",
+		WgAddr:       wgaddr.MustParseWGAddress("100.64.0.1/24"),
 		WgPrivateKey: key,
 		WgPort:       33100,
 		MTU:          iface.DefaultMTU,
@@ -654,7 +655,7 @@ func TestEngine_Sync(t *testing.T) {
 	relayMgr := relayClient.NewManager(ctx, nil, key.PublicKey().String(), iface.DefaultMTU)
 	engine := NewEngine(ctx, cancel, &EngineConfig{
 		WgIfaceName:  "utun103",
-		WgAddr:       "100.64.0.1/24",
+		WgAddr:       wgaddr.MustParseWGAddress("100.64.0.1/24"),
 		WgPrivateKey: key,
 		WgPort:       33100,
 		MTU:          iface.DefaultMTU,
@@ -824,7 +825,7 @@ func TestEngine_UpdateNetworkMapWithRoutes(t *testing.T) {
 			relayMgr := relayClient.NewManager(ctx, nil, key.PublicKey().String(), iface.DefaultMTU)
 			engine := NewEngine(ctx, cancel, &EngineConfig{
 				WgIfaceName:  wgIfaceName,
-				WgAddr:       wgAddr,
+				WgAddr:       wgaddr.MustParseWGAddress(wgAddr),
 				WgPrivateKey: key,
 				WgPort:       33100,
 				MTU:          iface.DefaultMTU,
@@ -842,7 +843,7 @@ func TestEngine_UpdateNetworkMapWithRoutes(t *testing.T) {
 
 			opts := iface.WGIFaceOpts{
 				IFaceName:    wgIfaceName,
-				Address:      wgAddr,
+				Address:      wgaddr.MustParseWGAddress(wgAddr),
 				WGPort:       engine.config.WgPort,
 				WGPrivKey:    key.String(),
 				MTU:          iface.DefaultMTU,
@@ -1031,7 +1032,7 @@ func TestEngine_UpdateNetworkMapWithDNSUpdate(t *testing.T) {
 			relayMgr := relayClient.NewManager(ctx, nil, key.PublicKey().String(), iface.DefaultMTU)
 			engine := NewEngine(ctx, cancel, &EngineConfig{
 				WgIfaceName:  wgIfaceName,
-				WgAddr:       wgAddr,
+				WgAddr:       wgaddr.MustParseWGAddress(wgAddr),
 				WgPrivateKey: key,
 				WgPort:       33100,
 				MTU:          iface.DefaultMTU,
@@ -1049,7 +1050,7 @@ func TestEngine_UpdateNetworkMapWithDNSUpdate(t *testing.T) {
 			}
 			opts := iface.WGIFaceOpts{
 				IFaceName:    wgIfaceName,
-				Address:      wgAddr,
+				Address:      wgaddr.MustParseWGAddress(wgAddr),
 				WGPort:       33100,
 				WGPrivKey:    key.String(),
 				MTU:          iface.DefaultMTU,
@@ -1559,7 +1560,7 @@ func createEngine(ctx context.Context, cancel context.CancelFunc, setupKey strin
 	wgPort := 33100 + i
 	conf := &EngineConfig{
 		WgIfaceName:  ifaceName,
-		WgAddr:       resp.PeerConfig.Address,
+		WgAddr:       wgaddr.MustParseWGAddress(resp.PeerConfig.Address),
 		WgPrivateKey: key,
 		WgPort:       wgPort,
 		MTU:          iface.DefaultMTU,
@@ -1704,3 +1705,205 @@ func getPeers(e *Engine) int {
 
 	return len(e.peerStore.PeersPubKey())
 }
+
+func TestEngine_hasIPv6Changed(t *testing.T) {
+	v4Only := wgaddr.MustParseWGAddress("100.64.0.1/16")
+
+	v4v6 := wgaddr.MustParseWGAddress("100.64.0.1/16")
+	v4v6.IPv6 = netip.MustParseAddr("fd00::1")
+	v4v6.IPv6Net = netip.MustParsePrefix("fd00::1/64").Masked()
+
+	tests := []struct {
+		name     string
+		current  wgaddr.Address
+		confV6   []byte
+		expected bool
+	}{
+		{
+			name:     "no v6 before, no v6 now",
+			current:  v4Only,
+			confV6:   nil,
+			expected: false,
+		},
+		{
+			name:     "no v6 before, v6 added",
+			current:  v4Only,
+			confV6:   netiputil.EncodeAddr(netip.MustParseAddr("fd00::1")),
+			expected: true,
+		},
+		{
+			name:     "had v6, now removed",
+			current:  v4v6,
+			confV6:   nil,
+			expected: true,
+		},
+		{
+			name:     "had v6, same v6",
+			current:  v4v6,
+			confV6:   netiputil.EncodeAddr(netip.MustParseAddr("fd00::1")),
+			expected: false,
+		},
+		{
+			name:     "had v6, different v6",
+			current:  v4v6,
+			confV6:   netiputil.EncodeAddr(netip.MustParseAddr("fd00::2")),
+			expected: true,
+		},
+		{
+			name:     "decode error keeps status quo",
+			current:  v4Only,
+			confV6:   []byte{1, 2, 3},
+			expected: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			engine := &Engine{
+				wgInterface: &MockWGIface{
+					AddressFunc: func() wgaddr.Address { return tt.current },
+				},
+			}
+			conf := &mgmtProto.PeerConfig{
+				AddressV6: tt.confV6,
+			}
+			assert.Equal(t, tt.expected, engine.hasIPv6Changed(conf))
+		})
+	}
+}
+
+func TestFilterAllowedIPs(t *testing.T) {
+	v4v6Addr := wgaddr.MustParseWGAddress("100.64.0.1/16")
+	v4v6Addr.IPv6 = netip.MustParseAddr("fd00::1")
+	v4v6Addr.IPv6Net = netip.MustParsePrefix("fd00::1/64").Masked()
+
+	v4OnlyAddr := wgaddr.MustParseWGAddress("100.64.0.1/16")
+
+	tests := []struct {
+		name     string
+		addr     wgaddr.Address
+		input    []string
+		expected []string
+	}{
+		{
+			name:     "interface has v6, keep all",
+			addr:     v4v6Addr,
+			input:    []string{"100.64.0.1/32", "fd00::1/128"},
+			expected: []string{"100.64.0.1/32", "fd00::1/128"},
+		},
+		{
+			name:     "no v6, strip v6",
+			addr:     v4OnlyAddr,
+			input:    []string{"100.64.0.1/32", "fd00::1/128"},
+			expected: []string{"100.64.0.1/32"},
+		},
+		{
+			name:     "no v6, only v4",
+			addr:     v4OnlyAddr,
+			input:    []string{"100.64.0.1/32", "10.0.0.0/8"},
+			expected: []string{"100.64.0.1/32", "10.0.0.0/8"},
+		},
+		{
+			name:     "no v6, only v6 input",
+			addr:     v4OnlyAddr,
+			input:    []string{"fd00::1/128", "::/0"},
+			expected: []string{},
+		},
+		{
+			name:     "no v6, invalid prefix preserved",
+			addr:     v4OnlyAddr,
+			input:    []string{"100.64.0.1/32", "garbage"},
+			expected: []string{"100.64.0.1/32", "garbage"},
+		},
+		{
+			name:     "no v6, empty input",
+			addr:     v4OnlyAddr,
+			input:    []string{},
+			expected: []string{},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			addr := tt.addr
+			engine := &Engine{
+				config: &EngineConfig{},
+				wgInterface: &MockWGIface{
+					AddressFunc: func() wgaddr.Address { return addr },
+				},
+			}
+			result := engine.filterAllowedIPs(tt.input)
+			assert.Equal(t, tt.expected, result)
+		})
+	}
+}
+
+func TestSplitAllowedIPs(t *testing.T) {
+	ourV6Net := netip.MustParsePrefix("fd00:1234:5678:abcd::/64")
+
+	tests := []struct {
+		name       string
+		allowedIPs []string
+		ourV6Net   netip.Prefix
+		wantV4     string
+		wantV6     string
+	}{
+		{
+			name:       "v4 only",
+			allowedIPs: []string{"100.64.0.1/32"},
+			ourV6Net:   ourV6Net,
+			wantV4:     "100.64.0.1",
+			wantV6:     "",
+		},
+		{
+			name:       "v4 and v6 overlay",
+			allowedIPs: []string{"100.64.0.1/32", "fd00:1234:5678:abcd::1/128"},
+			ourV6Net:   ourV6Net,
+			wantV4:     "100.64.0.1",
+			wantV6:     "fd00:1234:5678:abcd::1",
+		},
+		{
+			name:       "v4, routed v6, overlay v6",
+			allowedIPs: []string{"100.64.0.1/32", "2001:db8::1/128", "fd00:1234:5678:abcd::1/128"},
+			ourV6Net:   ourV6Net,
+			wantV4:     "100.64.0.1",
+			wantV6:     "fd00:1234:5678:abcd::1",
+		},
+		{
+			name:       "routed v6 /128 outside our subnet is ignored",
+			allowedIPs: []string{"100.64.0.1/32", "2001:db8::1/128"},
+			ourV6Net:   ourV6Net,
+			wantV4:     "100.64.0.1",
+			wantV6:     "",
+		},
+		{
+			name:       "routed v6 prefix is ignored",
+			allowedIPs: []string{"100.64.0.1/32", "fd00:1234:5678:abcd::/64"},
+			ourV6Net:   ourV6Net,
+			wantV4:     "100.64.0.1",
+			wantV6:     "",
+		},
+		{
+			name:       "no v6 subnet configured",
+			allowedIPs: []string{"100.64.0.1/32", "fd00:1234:5678:abcd::1/128"},
+			ourV6Net:   netip.Prefix{},
+			wantV4:     "100.64.0.1",
+			wantV6:     "",
+		},
+		{
+			name:       "v4 /24 route is ignored",
+			allowedIPs: []string{"100.64.0.0/24", "100.64.0.1/32"},
+			ourV6Net:   ourV6Net,
+			wantV4:     "100.64.0.1",
+			wantV6:     "",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			v4, v6 := splitAllowedIPs(tt.allowedIPs, tt.ourV6Net)
+			assert.Equal(t, tt.wantV4, v4, "v4")
+			assert.Equal(t, tt.wantV6, v6, "v6")
+		})
+	}
+}

client/internal/iface_common.go

@@ -26,7 +26,7 @@ type wgIfaceBase interface {
 	Address() wgaddr.Address
 	ToInterface() *net.Interface
 	Up() (*udpmux.UniversalUDPMuxDefault, error)
-	UpdateAddr(newAddr string) error
+	UpdateAddr(newAddr wgaddr.Address) error
 	GetProxy() wgproxy.Proxy
 	GetProxyPort() uint16
 	UpdatePeer(peerKey string, allowedIps []netip.Prefix, keepAlive time.Duration, endpoint *net.UDPAddr, preSharedKey *wgtypes.Key) error

client/internal/listener/network_change.go

@@ -5,4 +5,5 @@ type NetworkChangeListener interface {
 	// OnNetworkChanged invoke when network settings has been changed
 	OnNetworkChanged(string)
 	SetInterfaceIP(string)
+	SetInterfaceIPv6(string)
 }

client/internal/peer/status.go

@@ -53,6 +53,7 @@ type RouterState struct {
 type State struct {
 	Mux                        *sync.RWMutex
 	IP                         string
+	IPv6                       string
 	PubKey                     string
 	FQDN                       string
 	ConnStatus                 ConnStatus
@@ -106,6 +107,7 @@ func (s *State) GetRoutes() map[string]struct{} {
 // LocalPeerState contains the latest state of the local peer
 type LocalPeerState struct {
 	IP              string
+	IPv6            string
 	PubKey          string
 	KernelInterface bool
 	FQDN            string
@@ -259,7 +261,7 @@ func (d *Status) ReplaceOfflinePeers(replacement []State) {
 }
 
 // AddPeer adds peer to Daemon status map
-func (d *Status) AddPeer(peerPubKey string, fqdn string, ip string) error {
+func (d *Status) AddPeer(peerPubKey string, fqdn string, ip string, ipv6 string) error {
 	d.mux.Lock()
 	defer d.mux.Unlock()
 
@@ -270,6 +272,7 @@ func (d *Status) AddPeer(peerPubKey string, fqdn string, ip string) error {
 	d.peers[peerPubKey] = State{
 		PubKey:     peerPubKey,
 		IP:         ip,
+		IPv6:       ipv6,
 		ConnStatus: StatusIdle,
 		FQDN:       fqdn,
 		Mux:        new(sync.RWMutex),
@@ -1239,6 +1242,7 @@ func (fs FullStatus) ToProto() *proto.FullStatus {
 	}
 
 	pbFullStatus.LocalPeerState.IP = fs.LocalPeerState.IP
+	pbFullStatus.LocalPeerState.Ipv6 = fs.LocalPeerState.IPv6
 	pbFullStatus.LocalPeerState.PubKey = fs.LocalPeerState.PubKey
 	pbFullStatus.LocalPeerState.KernelInterface = fs.LocalPeerState.KernelInterface
 	pbFullStatus.LocalPeerState.Fqdn = fs.LocalPeerState.FQDN
@@ -1254,6 +1258,7 @@ func (fs FullStatus) ToProto() *proto.FullStatus {
 
 		pbPeerState := &proto.PeerState{
 			IP:                         peerState.IP,
+			Ipv6:                       peerState.IPv6,
 			PubKey:                     peerState.PubKey,
 			ConnStatus:                 peerState.ConnStatus.String(),
 			ConnStatusUpdate:           timestamppb.New(peerState.ConnStatusUpdate),

client/internal/peer/status_test.go

@@ -14,13 +14,13 @@ func TestAddPeer(t *testing.T) {
 	key := "abc"
 	ip := "100.108.254.1"
 	status := NewRecorder("https://mgm")
-	err := status.AddPeer(key, "abc.netbird", ip)
+	err := status.AddPeer(key, "abc.netbird", ip, "")
 	assert.NoError(t, err, "shouldn't return error")
 
 	_, exists := status.peers[key]
 	assert.True(t, exists, "value was found")
 
-	err = status.AddPeer(key, "abc.netbird", ip)
+	err = status.AddPeer(key, "abc.netbird", ip, "")
 
 	assert.Error(t, err, "should return error on duplicate")
 }
@@ -29,7 +29,7 @@ func TestGetPeer(t *testing.T) {
 	key := "abc"
 	ip := "100.108.254.1"
 	status := NewRecorder("https://mgm")
-	err := status.AddPeer(key, "abc.netbird", ip)
+	err := status.AddPeer(key, "abc.netbird", ip, "")
 	assert.NoError(t, err, "shouldn't return error")
 
 	peerStatus, err := status.GetPeer(key)
@@ -46,7 +46,7 @@ func TestUpdatePeerState(t *testing.T) {
 	ip := "10.10.10.10"
 	fqdn := "peer-a.netbird.local"
 	status := NewRecorder("https://mgm")
-	_ = status.AddPeer(key, fqdn, ip)
+	_ = status.AddPeer(key, fqdn, ip, "")
 
 	peerState := State{
 		PubKey:           key,
@@ -85,7 +85,7 @@ func TestGetPeerStateChangeNotifierLogic(t *testing.T) {
 	key := "abc"
 	ip := "10.10.10.10"
 	status := NewRecorder("https://mgm")
-	_ = status.AddPeer(key, "abc.netbird", ip)
+	_ = status.AddPeer(key, "abc.netbird", ip, "")
 
 	sub := status.SubscribeToPeerStateChanges(context.Background(), key)
 	assert.NotNil(t, sub, "channel shouldn't be nil")

client/internal/profilemanager/config.go

@@ -77,6 +77,7 @@ type ConfigInput struct {
 	DisableFirewall     *bool
 	BlockLANAccess      *bool
 	BlockInbound        *bool
+	DisableIPv6         *bool
 
 	DisableNotifications *bool
 
@@ -115,6 +116,7 @@ type Config struct {
 	DisableFirewall     bool
 	BlockLANAccess      bool
 	BlockInbound        bool
+	DisableIPv6         bool
 
 	DisableNotifications *bool
 
@@ -530,6 +532,16 @@ func (config *Config) apply(input ConfigInput) (updated bool, err error) {
 		updated = true
 	}
 
+	if input.DisableIPv6 != nil && *input.DisableIPv6 != config.DisableIPv6 {
+		if *input.DisableIPv6 {
+			log.Infof("disabling IPv6 overlay")
+		} else {
+			log.Infof("enabling IPv6 overlay")
+		}
+		config.DisableIPv6 = *input.DisableIPv6
+		updated = true
+	}
+
 	if input.DisableNotifications != nil && input.DisableNotifications != config.DisableNotifications {
 		if *input.DisableNotifications {
 			log.Infof("disabling notifications")

client/internal/routemanager/client/client_bench_test.go

@@ -46,7 +46,7 @@ func generateBenchmarkData(tier benchmarkTier) (*peer.Status, map[route.ID]*rout
 		fqdn := fmt.Sprintf("peer-%d.example.com", i)
 		ip := fmt.Sprintf("10.0.%d.%d", i/256, i%256)
 
-		err := statusRecorder.AddPeer(peerKey, fqdn, ip)
+		err := statusRecorder.AddPeer(peerKey, fqdn, ip, "")
 		if err != nil {
 			panic(fmt.Sprintf("failed to add peer: %v", err))
 		}

client/internal/routemanager/manager_test.go

@@ -12,6 +12,7 @@ import (
 	"github.com/stretchr/testify/require"
 
 	"github.com/netbirdio/netbird/client/iface"
+	"github.com/netbirdio/netbird/client/iface/wgaddr"
 	"github.com/netbirdio/netbird/client/internal/peer"
 	"github.com/netbirdio/netbird/route"
 )
@@ -409,7 +410,7 @@ func TestManagerUpdateRoutes(t *testing.T) {
 			}
 			opts := iface.WGIFaceOpts{
 				IFaceName:    fmt.Sprintf("utun43%d", n),
-				Address:      "100.65.65.2/24",
+				Address:      wgaddr.MustParseWGAddress("100.65.65.2/24"),
 				WGPort:       33100,
 				WGPrivKey:    peerPrivateKey.String(),
 				MTU:          iface.DefaultMTU,

client/internal/routemanager/systemops/systemops_generic_test.go

@@ -21,6 +21,7 @@ import (
 	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
 
 	"github.com/netbirdio/netbird/client/iface"
+	"github.com/netbirdio/netbird/client/iface/wgaddr"
 	"github.com/netbirdio/netbird/client/internal/routemanager/vars"
 	nbnet "github.com/netbirdio/netbird/client/net"
 )
@@ -441,7 +442,7 @@ func createWGInterface(t *testing.T, interfaceName, ipAddressCIDR string, listen
 
 	opts := iface.WGIFaceOpts{
 		IFaceName:    interfaceName,
-		Address:      ipAddressCIDR,
+		Address:      wgaddr.MustParseWGAddress(ipAddressCIDR),
 		WGPrivKey:    peerPrivateKey.String(),
 		WGPort:       listenPort,
 		MTU:          iface.DefaultMTU,