diff --git a/sys/netinet6/nd6.c b/sys/netinet6/nd6.c
index e9c4bb53b693..faab9f0adc8b 100644
--- a/sys/netinet6/nd6.c
+++ b/sys/netinet6/nd6.c
@@ -113,7 +113,7 @@ VNET_DEFINE(int, nd6_debug) = 1;
 VNET_DEFINE(int, nd6_debug) = 0;
 #endif
 
-static eventhandler_tag lle_event_eh, iflladdr_event_eh;
+static eventhandler_tag lle_event_eh, iflladdr_event_eh, ifnet_link_event_eh;
 
 VNET_DEFINE(struct nd_drhead, nd_defrouter);
 VNET_DEFINE(struct nd_prhead, nd_prefix);
@@ -233,6 +233,8 @@ nd6_init(void)
 		    NULL, EVENTHANDLER_PRI_ANY);
 		iflladdr_event_eh = EVENTHANDLER_REGISTER(iflladdr_event,
 		    nd6_iflladdr, NULL, EVENTHANDLER_PRI_ANY);
+		ifnet_link_event_eh = EVENTHANDLER_REGISTER(ifnet_link_event,
+		    nd6_ifnet_link_event, NULL, EVENTHANDLER_PRI_ANY);
 	}
 }
 
@@ -244,6 +246,7 @@ nd6_destroy()
 	callout_drain(&V_nd6_slowtimo_ch);
 	callout_drain(&V_nd6_timer_ch);
 	if (IS_DEFAULT_VNET(curvnet)) {
+		EVENTHANDLER_DEREGISTER(ifnet_link_event, ifnet_link_event_eh);
 		EVENTHANDLER_DEREGISTER(lle_event, lle_event_eh);
 		EVENTHANDLER_DEREGISTER(iflladdr_event, iflladdr_event_eh);
 	}
diff --git a/sys/netinet6/nd6.h b/sys/netinet6/nd6.h
index 434c810301c6..ffc88cb5fdbb 100644
--- a/sys/netinet6/nd6.h
+++ b/sys/netinet6/nd6.h
@@ -476,6 +476,7 @@ void nd6_dad_stop(struct ifaddr *);
 /* nd6_rtr.c */
 void nd6_rs_input(struct mbuf *, int, int);
 void nd6_ra_input(struct mbuf *, int, int);
+void nd6_ifnet_link_event(void *, struct ifnet *, int);
 void defrouter_reset(void);
 void defrouter_select_fib(int fibnum);
 void defrouter_select(void);
diff --git a/sys/netinet6/nd6_rtr.c b/sys/netinet6/nd6_rtr.c
index 3e18c355b7cb..424baa119f98 100644
--- a/sys/netinet6/nd6_rtr.c
+++ b/sys/netinet6/nd6_rtr.c
@@ -285,8 +285,33 @@ defrtr_ipv6_only_ifp(struct ifnet *ifp)
 	/* Send notification of flag change. */
 #endif
 }
+
+static void
+defrtr_ipv6_only_ipf_down(struct ifnet *ifp)
+{
+
+	IF_AFDATA_WLOCK(ifp);
+	ND_IFINFO(ifp)->flags &= ~ND6_IFF_IPV6_ONLY;
+	IF_AFDATA_WUNLOCK(ifp);
+}
 #endif	/* EXPERIMENTAL */
 
+void
+nd6_ifnet_link_event(void *arg __unused, struct ifnet *ifp, int linkstate)
+{
+
+	/*
+	 * XXX-BZ we might want to trigger re-evaluation of our default router
+	 * availability. E.g., on link down the default router might be
+	 * unreachable but a different interface might still have connectivity.
+	 */
+
+#ifdef EXPERIMENTAL
+	if (linkstate == LINK_STATE_DOWN)
+		defrtr_ipv6_only_ipf_down(ifp);
+#endif
+}
+
 /*
  * Receive Router Advertisement Message.
  *