diff --git a/nest/iface.h b/nest/iface.h
index 8051363a..7a363621 100644
--- a/nest/iface.h
+++ b/nest/iface.h
@@ -34,6 +34,7 @@ struct ifa {
   ip_addr prefix;			/* Network prefix */
   unsigned pxlen;			/* Prefix length */
   ip_addr brd;				/* Broadcast address */
+  ip_addr opposite;			/* Opposite end of a point-to-point link */
   struct neighbor *neigh;		/* List of neighbors on this interface */
 };