diff --git a/nest/iface.c b/nest/iface.c
index a3dff4af..28e7739b 100644
--- a/nest/iface.c
+++ b/nest/iface.c
@@ -23,7 +23,6 @@ static void auto_router_id(void);
  *	Neighbor Cache
  *
  *	FIXME: Use hashing to get some real speed.
- *	FIXME: Cleanup when a protocol goes down.
  */
 
 static slab *neigh_slab;
@@ -160,6 +159,30 @@ neigh_if_down(struct iface *i)
     }
 }
 
+void
+neigh_prune(void)
+{
+  neighbor *n, *m, **N;
+  struct iface *i;
+
+  DBG("Pruning neighbors\n");
+  WALK_LIST(i, iface_list)
+    {
+      N = &i->neigh;
+      while (n = *N)
+	{
+	  if (n->proto->core_state == FS_HUNGRY || n->proto->core_state == FS_FLUSHING)
+	    {
+	      *N = n->sibling;
+	      rem_node(&n->n);
+	      sl_free(neigh_slab, n);
+	      continue;
+	    }
+	  N = &n->sibling;
+	}
+    }
+}
+
 /*
  *	The Interface List
  */
diff --git a/nest/iface.h b/nest/iface.h
index 83cbdb07..378cf3d1 100644
--- a/nest/iface.h
+++ b/nest/iface.h
@@ -89,6 +89,7 @@ neighbor *neigh_find(struct proto *, ip_addr *, unsigned flags);
 
 void neigh_dump(neighbor *);
 void neigh_dump_all(void);
+void neigh_prune(void);
 
 /*
  *	Interface Pattern Lists
diff --git a/nest/proto.c b/nest/proto.c
index f96d37dc..21f36307 100644
--- a/nest/proto.c
+++ b/nest/proto.c
@@ -330,6 +330,7 @@ proto_flush_all(void *unused)
   struct proto *p;
 
   rt_prune(&master_table);
+  neigh_prune();
   while ((p = HEAD(flush_proto_list))->n.next)
     {
       DBG("Flushing protocol %s\n", p->name);