diff --git a/sys/net/if.c b/sys/net/if.c
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -278,7 +278,6 @@
 static int	ifconf(u_long, caddr_t);
 static void	if_input_default(struct ifnet *, struct mbuf *);
 static int	if_requestencap_default(struct ifnet *, struct if_encap_req *);
-static void	if_route(struct ifnet *, int flag, int fam);
 static int	if_setflag(struct ifnet *, int, int, int *, int);
 static int	if_transmit_default(struct ifnet *ifp, struct mbuf *m);
 static void	if_unroute(struct ifnet *, int flag, int fam);
@@ -2141,26 +2140,6 @@
 	rt_ifmsg(ifp, IFF_UP);
 }
 
-/*
- * Mark an interface up and notify protocols of
- * the transition.
- */
-static void
-if_route(struct ifnet *ifp, int flag, int fam)
-{
-
-	KASSERT(flag == IFF_UP, ("if_route: flag != IFF_UP"));
-
-	ifp->if_flags |= flag;
-	getmicrotime(&ifp->if_lastchange);
-	if (ifp->if_carp)
-		(*carp_linkstate_p)(ifp);
-	rt_ifmsg(ifp, IFF_UP);
-#ifdef INET6
-	in6_if_up(ifp);
-#endif
-}
-
 void	(*vlan_link_state_p)(struct ifnet *);	/* XXX: private from if_vlan */
 void	(*vlan_trunk_cap_p)(struct ifnet *);		/* XXX: private from if_vlan */
 struct ifnet *(*vlan_trunkdev_p)(struct ifnet *);
@@ -2246,7 +2225,11 @@
 if_up(struct ifnet *ifp)
 {
 
-	if_route(ifp, IFF_UP, AF_UNSPEC);
+	ifp->if_flags |= IFF_UP;
+	getmicrotime(&ifp->if_lastchange);
+	if (ifp->if_carp)
+		(*carp_linkstate_p)(ifp);
+	rt_ifmsg(ifp, IFF_UP);
 	EVENTHANDLER_INVOKE(ifnet_event, ifp, IFNET_EVENT_UP);
 }
 
@@ -3109,13 +3092,8 @@
 	    cmd != SIOCSIFDSTADDR && cmd != SIOCSIFNETMASK)
 		error = (*ifp->if_ioctl)(ifp, cmd, data);
 
-	if ((oif_flags ^ ifp->if_flags) & IFF_UP) {
-#ifdef INET6
-		if (ifp->if_flags & IFF_UP)
-			in6_if_up(ifp);
-#endif
-	}
-
+	if (!(oif_flags & IFF_UP) && (ifp->if_flags & IFF_UP))
+		if_up(ifp);
 out_ref:
 	if_rele(ifp);
 out_noref:
diff --git a/sys/netinet6/in6.c b/sys/netinet6/in6.c
--- a/sys/netinet6/in6.c
+++ b/sys/netinet6/in6.c
@@ -2049,6 +2049,20 @@
 	in6_ifattach(ifp, NULL);
 }
 
+static void
+in6_ifevent(void *arg __unused, struct ifnet *ifp, int event)
+{
+	if (event == IFNET_EVENT_UP)
+		in6_if_up(ifp);
+}
+
+static void
+in6_init(void *arg __unused)
+{
+	EVENTHANDLER_REGISTER(ifnet_event, in6_ifevent, NULL, EVENTHANDLER_PRI_ANY);
+}
+SYSINIT(in6_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, in6_init, NULL);
+
 int
 in6if_do_dad(struct ifnet *ifp)
 {
diff --git a/sys/netlink/route/iface.c b/sys/netlink/route/iface.c
--- a/sys/netlink/route/iface.c
+++ b/sys/netlink/route/iface.c
@@ -1292,10 +1292,8 @@
 		error = EAFNOSUPPORT;
 	}
 
-#ifdef INET6
 	if (error == 0 && !(if_flags & IFF_UP) && (if_getflags(ifp) & IFF_UP))
-		in6_if_up(ifp);
-#endif
+		if_up(ifp);
 
 	if_rele(ifp);