diff --git a/go/native/GoGlue.cpp b/go/native/GoGlue.cpp
index b94b54578..bd7509237 100644
--- a/go/native/GoGlue.cpp
+++ b/go/native/GoGlue.cpp
@@ -110,6 +110,8 @@ extern "C" int goStateObjectGetFunc(ZT_GoNode *,int,const uint64_t [2],void *,un
 extern "C" void goDNSResolverFunc(ZT_GoNode *,const uint8_t *,int,const char *,uintptr_t);
 extern "C" int goVirtualNetworkConfigFunc(ZT_GoNode *,ZT_GoTap *,uint64_t,int,const ZT_VirtualNetworkConfig *);
 extern "C" void goZtEvent(ZT_GoNode *,int,const void *);
+extern "C" void goHandleTapAddedMulticastGroup(ZT_GoNode *,ZT_GoTap *,uint64_t,uint64_t,uint32_t);
+extern "C" void goHandleTapRemovedMulticastGroup(ZT_GoNode *,ZT_GoTap *,uint64_t,uint64_t,uint32_t);
 
 static int ZT_GoNode_VirtualNetworkConfigFunction(
 	ZT_Node *node,
@@ -334,11 +336,26 @@ extern "C" ZT_GoNode *ZT_GoNode_new(const char *workingPath)
 		gn->run = true;
 
 		gn->backgroundTaskThread = std::thread([gn] {
+			int64_t lastScannedMulticastGroups = 0;
 			while (gn->run) {
-				std::this_thread::sleep_for(std::chrono::milliseconds(250));
+				std::this_thread::sleep_for(std::chrono::milliseconds(500));
 				const int64_t now = OSUtils::now();
 				if (now >= gn->nextBackgroundTaskDeadline)
 					gn->node->processBackgroundTasks(nullptr,now,&(gn->nextBackgroundTaskDeadline));
+				if ((now - lastScannedMulticastGroups) > 5000) {
+					lastScannedMulticastGroups = now;
+					std::vector<MulticastGroup> added,removed;
+					std::lock_guard<std::mutex> tl(gn->taps_l);
+					for(auto t=gn->taps.begin();t!=gn->taps.end();++t) {
+						added.clear();
+						removed.clear();
+						t->second->scanMulticastGroups(added,removed);
+						for(auto g=added.begin();g!=added.end();++g)
+							goHandleTapAddedMulticastGroup(gn,(ZT_GoTap *)t->second.get(),t->first,g->mac().toInt(),g->adi());
+						for(auto g=removed.begin();g!=removed.end();++g)
+							goHandleTapRemovedMulticastGroup(gn,(ZT_GoTap *)t->second.get(),t->first,g->mac().toInt(),g->adi());
+					}
+				}
 			}
 		});
 
diff --git a/go/pkg/zerotier/nativetap.go b/go/pkg/zerotier/nativetap.go
index d71086331..1c448236b 100644
--- a/go/pkg/zerotier/nativetap.go
+++ b/go/pkg/zerotier/nativetap.go
@@ -16,6 +16,7 @@ package zerotier
 import (
 	"fmt"
 	"net"
+	"sync"
 	"sync/atomic"
 	"unsafe"
 )
@@ -30,9 +31,11 @@ import "C"
 
 // nativeTap is a Tap implementation that wraps a native C++ interface to a system tun/tap device
 type nativeTap struct {
-	tap           unsafe.Pointer
-	networkStatus uint32
-	enabled       uint32
+	tap                        unsafe.Pointer
+	networkStatus              uint32
+	enabled                    uint32
+	multicastGroupHandlers     []func(bool, *MulticastGroup)
+	multicastGroupHandlersLock sync.Mutex
 }
 
 // SetEnabled sets this tap's enabled state
@@ -56,12 +59,12 @@ func (t *nativeTap) AddIP(ip net.IPNet) error {
 		if bits > 128 || bits < 0 {
 			return ErrInvalidParameter
 		}
-		C.ZT_GoTap_addIp(t.tap, afInet6, unsafe.Pointer(&ip.IP[0]), C.int(bits))
+		C.ZT_GoTap_addIp(t.tap, C.int(afInet6), unsafe.Pointer(&ip.IP[0]), C.int(bits))
 	} else if len(ip.IP) == 4 {
 		if bits > 32 || bits < 0 {
 			return ErrInvalidParameter
 		}
-		C.ZT_GoTap_addIp(t.tap, afInet, unsafe.Pointer(&ip.IP[0]), C.int(bits))
+		C.ZT_GoTap_addIp(t.tap, C.int(afInet), unsafe.Pointer(&ip.IP[0]), C.int(bits))
 	}
 	return ErrInvalidParameter
 }
@@ -73,14 +76,14 @@ func (t *nativeTap) RemoveIP(ip net.IPNet) error {
 		if bits > 128 || bits < 0 {
 			return ErrInvalidParameter
 		}
-		C.ZT_GoTap_removeIp(t.tap, afInet6, unsafe.Pointer(&ip.IP[0]), C.int(bits))
+		C.ZT_GoTap_removeIp(t.tap, C.int(afInet6), unsafe.Pointer(&ip.IP[0]), C.int(bits))
 		return nil
 	}
 	if len(ip.IP) == 4 {
 		if bits > 32 || bits < 0 {
 			return ErrInvalidParameter
 		}
-		C.ZT_GoTap_removeIp(t.tap, afInet, unsafe.Pointer(&ip.IP[0]), C.int(bits))
+		C.ZT_GoTap_removeIp(t.tap, C.int(afInet), unsafe.Pointer(&ip.IP[0]), C.int(bits))
 		return nil
 	}
 	return ErrInvalidParameter
@@ -98,7 +101,7 @@ func (t *nativeTap) IPs() (ips []net.IPNet, err error) {
 	count := int(C.ZT_GoTap_ips(t.tap, unsafe.Pointer(&ipbuf[0]), 16384))
 	ipptr := 0
 	for i := 0; i < count; i++ {
-		af := ipbuf[ipptr]
+		af := int(ipbuf[ipptr])
 		ipptr++
 		switch af {
 		case afInet:
@@ -135,3 +138,10 @@ func (t *nativeTap) DeviceName() string {
 	}
 	return ""
 }
+
+// AddMulticastGroupChangeHandler adds a function to be called when the tap subscribes or unsubscribes to a multicast group.
+func (t *nativeTap) AddMulticastGroupChangeHandler(handler func(bool, *MulticastGroup)) {
+	t.multicastGroupHandlersLock.Lock()
+	t.multicastGroupHandlers = append(t.multicastGroupHandlers, handler)
+	t.multicastGroupHandlersLock.Unlock()
+}
diff --git a/go/pkg/zerotier/network.go b/go/pkg/zerotier/network.go
index 3d30c5040..e2a4b5b14 100644
--- a/go/pkg/zerotier/network.go
+++ b/go/pkg/zerotier/network.go
@@ -106,15 +106,26 @@ type NetworkConfig struct {
 
 // Network is a currently joined network
 type Network struct {
+	id         NetworkID
 	config     NetworkConfig
 	configLock sync.RWMutex
-	tap        *Tap
+	tap        Tap
 	tapLock    sync.Mutex
 }
 
+// ID gets this network's unique ID
+func (n *Network) ID() NetworkID { return n.id }
+
 // Config returns a copy of this network's current configuration
 func (n *Network) Config() NetworkConfig {
 	n.configLock.RLock()
 	defer n.configLock.RUnlock()
 	return n.config
 }
+
+// Tap gets this network's tap device
+func (n *Network) Tap() Tap {
+	n.tapLock.Lock()
+	defer n.tapLock.Unlock()
+	return n.tap
+}
diff --git a/go/pkg/zerotier/node-callbacks.go b/go/pkg/zerotier/node-callbacks.go
index 31e5024e4..98efb9ddc 100644
--- a/go/pkg/zerotier/node-callbacks.go
+++ b/go/pkg/zerotier/node-callbacks.go
@@ -29,8 +29,8 @@ import (
 )
 
 const (
-	afInet  = C.AF_INET
-	afInet6 = C.AF_INET6
+	afInet  int = C.AF_INET
+	afInet6 int = C.AF_INET6
 
 	networkStatusRequestingConfiguration = C.ZT_NETWORK_STATUS_REQUESTING_CONFIGURATION
 	networkStatusOK                      = C.ZT_NETWORK_STATUS_OK
@@ -68,11 +68,11 @@ func goPathLookupFunc(gn unsafe.Pointer, ztAddress C.uint64_t, desiredAddressFam
 	ip, port := node.pathLookup(uint64(ztAddress))
 	ip4 := ip.To4()
 	if len(ip4) == 4 {
-		*((*C.int)(familyP)) = afInet
+		*((*C.int)(familyP)) = C.int(afInet)
 		copy((*[4]byte)(ipP)[:], ip4)
 		*((*C.int)(portP)) = C.int(port)
 	} else if len(ip) == 16 {
-		*((*C.int)(familyP)) = afInet6
+		*((*C.int)(familyP)) = C.int(afInet6)
 		copy((*[16]byte)(ipP)[:], ip)
 		*((*C.int)(portP)) = C.int(port)
 	}
@@ -178,3 +178,39 @@ func goZtEvent(gn unsafe.Pointer, eventType C.int, data unsafe.Pointer) {
 		node.handleRemoteTrace(uint64(rt.origin), C.GoBytes(unsafe.Pointer(rt.data), C.int(rt.len)))
 	}
 }
+
+func handleTapMulticastGroupChange(gn unsafe.Pointer, nwid, mac C.uint64_t, adi C.uint32_t, added bool) {
+	nodesByUserPtrLock.RLock()
+	node := nodesByUserPtr[uintptr(gn)]
+	nodesByUserPtrLock.RUnlock()
+	if node == nil {
+		return
+	}
+
+	node.networksLock.RLock()
+	network := node.networks[uint64(nwid)]
+	node.networksLock.RUnlock()
+
+	network.tapLock.Lock()
+	tap, _ := network.tap.(*nativeTap)
+	network.tapLock.Unlock()
+
+	if tap != nil {
+		mg := &MulticastGroup{MAC: MAC(mac), ADI: uint32(adi)}
+		tap.multicastGroupHandlersLock.Lock()
+		defer tap.multicastGroupHandlersLock.Unlock()
+		for _, h := range tap.multicastGroupHandlers {
+			h(added, mg)
+		}
+	}
+}
+
+//export goHandleTapAddedMulticastGroup
+func goHandleTapAddedMulticastGroup(gn, tapP unsafe.Pointer, nwid, mac C.uint64_t, adi C.uint32_t) {
+	handleTapMulticastGroupChange(gn, nwid, mac, adi, true)
+}
+
+//export goHandleTapRemovedMulticastGroup
+func goHandleTapRemovedMulticastGroup(gn, tapP unsafe.Pointer, nwid, mac C.uint64_t, adi C.uint32_t) {
+	handleTapMulticastGroupChange(gn, nwid, mac, adi, false)
+}
diff --git a/go/pkg/zerotier/tap.go b/go/pkg/zerotier/tap.go
index c0dbb8c1b..d6833bedc 100644
--- a/go/pkg/zerotier/tap.go
+++ b/go/pkg/zerotier/tap.go
@@ -23,4 +23,5 @@ type Tap interface {
 	RemoveIP(ip net.IPNet) error
 	IPs() ([]net.IPNet, error)
 	DeviceName() string
+	AddMulticastGroupChangeHandler(func(bool, *MulticastGroup))
 }