package/network/services/odhcpd/patches/001-modify-route-when-v6-addr-change.patch

--- a/src/ndp.c
+++ b/src/ndp.c
@@ -38,6 +38,7 @@ static void setup_route(struct in6_addr
 static void setup_addr_for_relaying(struct in6_addr *addr, struct interface *iface, bool add);
 static void handle_solicit(void *addr, void *data, size_t len,
 		struct interface *iface, void *dest);
+static void ping6(struct in6_addr *addr, const struct interface *iface);
 
 /* Filter ICMPv6 messages of type neighbor solicitation */
 static struct sock_filter bpf[] = {
@@ -235,6 +236,7 @@ int ndp_setup_interface(struct interface
 static void ndp_netevent_cb(unsigned long event, struct netevent_handler_info *info)
 {
 	struct interface *iface = info->iface;
+	struct interface *c;
 	bool add = true;
 
 	if (!iface || iface->ndp == MODE_DISABLED)
@@ -247,6 +249,16 @@ static void ndp_netevent_cb(unsigned lon
 		/* fall through */
 	case NETEV_ADDR6_ADD:
 		setup_addr_for_relaying(&info->addr.in6, iface, add);
+		if (iface->ndp == MODE_RELAY && iface->master) {
+			avl_for_each_element(&interfaces, c, avl) {
+				syslog(LOG_DEBUG, "setup_route add:%d. dev:%s(%d) %d", add, c->name, c->ifindex, c->ndp);
+				if (c->ndp == MODE_RELAY && !c->master)
+					netlink_setup_route(&info->addr.in6, 64, c->ifindex, NULL, 1024, add);
+			}
+		}
+		/* Keep neighbor entries alive so we don't loose routes */
+		if (add)
+			ping6(&info->addr.in6, iface);
 		break;
 	case NETEV_NEIGH6_DEL:
 		add = false;
@@ -271,6 +283,8 @@ static void ndp_netevent_cb(unsigned lon
 
 		if (!add)
 			netlink_dump_neigh_table(false);
+		else
+			ping6(&info->addr.in6, iface);
 		break;
 	default:
 		break;
--- a/src/netlink.c
+++ b/src/netlink.c
@@ -179,7 +179,7 @@ static void refresh_iface_addr4(int ifin
 	free(addr);
 }
 
-static void refresh_iface_addr6(int ifindex)
+static void refresh_iface_addr6(int ifindex, bool add)
 {
 	struct odhcpd_ipaddr *addr = NULL;
 	struct interface *iface;
@@ -283,6 +283,17 @@ static void refresh_iface_addr6(int ifin
 			break;
 
 		memcpy(addr, iface->addr6, len * sizeof(*addr));
+
+		if (iface->ndp == MODE_RELAY && iface->master) {
+			// Replay address changes on all slave interfaces
+			struct interface *c;
+			avl_for_each_element(&interfaces, c, avl) {
+				syslog(LOG_DEBUG, "Replay address changes on all slave interfaces @ %s %d %d %d", c->name, c->ifindex, c->ndp, c->master);
+				if (c->ndp == MODE_RELAY && !c->master) {
+					netlink_setup_addr(addr, c->ifindex, true, add);
+				}
+			}
+		}
 	}
 
 	free(addr);
@@ -415,7 +426,7 @@ static int handle_rtm_addr(struct nlmsgh
 							&event_info);
 		}
 
-		refresh_iface_addr6(ifa->ifa_index);
+		refresh_iface_addr6(ifa->ifa_index, add);
 	} else {
 		if (!nla[IFA_LOCAL])
 			return NL_SKIP;