Index: sys/net/route.h
===================================================================
--- sys/net/route.h	(revision 251615)
+++ sys/net/route.h	(working copy)
@@ -185,6 +185,9 @@
 
 #define	RTF_RNH_LOCKED	 0x40000000	/* radix node head is locked */
 
+#define	RTF_RTAPP_COMPAT 0x80000000	/* a compatibility bit for interacting
+					   with existing routing apps */
+
 /* Mask of RTF flags that are allowed to be modified by RTM_CHANGE. */
 #define RTF_FMASK	\
 	(RTF_PROTO1 | RTF_PROTO2 | RTF_PROTO3 | RTF_BLACKHOLE | \
Index: sys/net/rtsock.c
===================================================================
--- sys/net/rtsock.c	(revision 251615)
+++ sys/net/rtsock.c	(working copy)
@@ -652,8 +652,10 @@
 		 */
 		if (gw_ro.ro_rt != NULL &&
 		    gw_ro.ro_rt->rt_gateway->sa_family == AF_LINK &&
-		    gw_ro.ro_rt->rt_ifp->if_flags & IFF_LOOPBACK)
+		    gw_ro.ro_rt->rt_ifp->if_flags & IFF_LOOPBACK) {
 			info.rti_flags &= ~RTF_GATEWAY;
+			info.rti_flags |= RTF_RTAPP_COMPAT;
+		}
 		if (gw_ro.ro_rt != NULL)
 			RTFREE(gw_ro.ro_rt);
 	}
@@ -853,7 +855,11 @@
 				Free(rtm); rtm = new_rtm;
 			}
 			(void)rt_msg2(rtm->rtm_type, &info, (caddr_t)rtm, NULL);
-			rtm->rtm_flags = rt->rt_flags;
+			if (rt->rt_flags & RTF_RTAPP_COMPAT)
+				rtm->rtm_flags = RTF_GATEWAY | 
+					(rt->rt_flags & ~RTF_RTAPP_COMPAT);
+			else
+				rtm->rtm_flags = rt->rt_flags;
 			rt_getmetrics(&rt->rt_rmx, &rtm->rtm_rmx);
 			rtm->rtm_addrs = info.rti_addrs;
 			break;
@@ -905,6 +911,7 @@
 					RT_UNLOCK(rt);
 					senderr(error);
 				}
+				rt->rt_flags &= ~RTF_GATEWAY;
 				rt->rt_flags |= (RTF_GATEWAY & info.rti_flags);
 			}
 			if (info.rti_ifa != NULL &&