diff --git a/sys/net/if.c b/sys/net/if.c
index 3a7c15cc2ec6..982fc002cd8e 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -377,15 +377,13 @@ void
 if_up(ifp)
 	register struct ifnet *ifp;
 {
+	register struct ifaddr *ifa;
 
 	ifp->if_flags |= IFF_UP;
 	microtime(&ifp->if_lastchange);
-#ifdef notyet
-	register struct ifaddr *ifa;
-	/* this has no effect on IP, and will kill all iso connections XXX */
-	for (ifa = ifp->if_addrlist; ifa; ifa = ifa->ifa_next)
+	for (ifa = ifp->if_addrhead.tqh_first; ifa; 
+	     ifa = ifa->ifa_link.tqe_next)
 		pfctlinput(PRC_IFUP, ifa->ifa_addr);
-#endif
 	rt_ifmsg(ifp);
 }
 
diff --git a/sys/sys/protosw.h b/sys/sys/protosw.h
index 5b48ee9cd92f..06b03c9baf10 100644
--- a/sys/sys/protosw.h
+++ b/sys/sys/protosw.h
@@ -224,6 +224,7 @@ extern	struct pr_usrreqs pru_oldstyle;
  */
 #define	PRC_IFDOWN		0	/* interface transition */
 #define	PRC_ROUTEDEAD		1	/* select new route if possible ??? */
+#define	PRC_IFUP		2 	/* interface has come back up */
 #define	PRC_QUENCH2		3	/* DEC congestion bit says slow down */
 #define	PRC_QUENCH		4	/* some one said to slow down */
 #define	PRC_MSGSIZE		5	/* message size forced drop */
@@ -250,7 +251,7 @@ extern	struct pr_usrreqs pru_oldstyle;
 
 #ifdef PRCREQUESTS
 char	*prcrequests[] = {
-	"IFDOWN", "ROUTEDEAD", "#2", "DEC-BIT-QUENCH2",
+	"IFDOWN", "ROUTEDEAD", "IFUP", "DEC-BIT-QUENCH2",
 	"QUENCH", "MSGSIZE", "HOSTDEAD", "#7",
 	"NET-UNREACH", "HOST-UNREACH", "PROTO-UNREACH", "PORT-UNREACH",
 	"#12", "SRCFAIL-UNREACH", "NET-REDIRECT", "HOST-REDIRECT",