diff --git a/NEWS b/NEWS
index 9669392d..6281c8a3 100644
--- a/NEWS
+++ b/NEWS
@@ -14,6 +14,13 @@ Version 2.0.0-pre0 (2016-12-07)
   doc/bird.conf.example2 for configuration examples.
 
 
+Version 1.6.3 (2016-12-21)
+  o Large BGP communities
+  o BFD authentication (MD5, SHA1)
+  o SHA1 and SHA2 authentication for RIP and OSPF
+  o Improved documentation
+  o Several bug fixes
+
 Version 1.6.2 (2016-09-29)
   o Fixes serious bug introduced in the previous version
 
diff --git a/filter/filter.c b/filter/filter.c
index 4ec04554..a6ef1e10 100644
--- a/filter/filter.c
+++ b/filter/filter.c
@@ -1579,6 +1579,7 @@ i_same(struct f_inst *f1, struct f_inst *f2)
   case P('<','='): TWOARGS; break;
 
   case '!': ONEARG; break;
+  case P('!', '~'):
   case '~': TWOARGS; break;
   case P('d','e'): ONEARG; break;
 
diff --git a/lib/hash.h b/lib/hash.h
index b37d8fa5..97d8f69c 100644
--- a/lib/hash.h
+++ b/lib/hash.h
@@ -25,6 +25,12 @@
     (v).data = mb_allocz(pool, HASH_SIZE(v) * sizeof(* (v).data));	\
   })
 
+#define HASH_FREE(v)							\
+  ({									\
+    mb_free((v).data);							\
+    (v) = (typeof(v)){ };						\
+  })
+
 #define HASH_FIND(v,id,key...)						\
   ({									\
     u32 _h = HASH_FN(v, id, key);					\
diff --git a/nest/a-set.c b/nest/a-set.c
index 82bf8b0d..a2fb6953 100644
--- a/nest/a-set.c
+++ b/nest/a-set.c
@@ -233,6 +233,26 @@ lc_set_contains(struct adata *list, lcomm val)
   return 0;
 }
 
+struct adata *
+int_set_prepend(struct linpool *pool, struct adata *list, u32 val)
+{
+  struct adata *res;
+  int len;
+
+  if (int_set_contains(list, val))
+    return list;
+
+  len = list ? list->length : 0;
+  res = lp_alloc(pool, sizeof(struct adata) + len + 4);
+  res->length = len + 4;
+
+  if (list)
+    memcpy(res->data + 4, list->data, list->length);
+
+  * (u32 *) res->data = val;
+
+  return res;
+}
 
 struct adata *
 int_set_add(struct linpool *pool, struct adata *list, u32 val)
@@ -250,8 +270,7 @@ int_set_add(struct linpool *pool, struct adata *list, u32 val)
   if (list)
     memcpy(res->data, list->data, list->length);
 
-  u32 *c = (u32 *) (res->data + len);
-  *c = val;
+  * (u32 *) (res->data + len) = val;
 
   return res;
 }
diff --git a/nest/attrs.h b/nest/attrs.h
index 84403cf3..f66d4f04 100644
--- a/nest/attrs.h
+++ b/nest/attrs.h
@@ -181,6 +181,7 @@ int lc_set_format(struct adata *set, int from, byte *buf, uint size);
 int int_set_contains(struct adata *list, u32 val);
 int ec_set_contains(struct adata *list, u64 val);
 int lc_set_contains(struct adata *list, lcomm val);
+struct adata *int_set_prepend(struct linpool *pool, struct adata *list, u32 val);
 struct adata *int_set_add(struct linpool *pool, struct adata *list, u32 val);
 struct adata *ec_set_add(struct linpool *pool, struct adata *list, u64 val);
 struct adata *lc_set_add(struct linpool *pool, struct adata *list, lcomm val);
diff --git a/proto/bgp/attrs.c b/proto/bgp/attrs.c
index d5bf2add..73318c6a 100644
--- a/proto/bgp/attrs.c
+++ b/proto/bgp/attrs.c
@@ -1224,6 +1224,15 @@ bgp_init_prefix_table(struct bgp_channel *c)
   c->prefix_slab = alen ? sl_new(c->pool, sizeof(struct bgp_prefix) + alen) : NULL;
 }
 
+void
+bgp_free_prefix_table(struct bgp_channel *c)
+{
+  HASH_FREE(c->prefix_hash);
+
+  rfree(c->prefix_slab);
+  c->prefix_slab = NULL;
+}
+
 static struct bgp_prefix *
 bgp_get_prefix(struct bgp_channel *c, net_addr *net, u32 path_id)
 {
@@ -1323,6 +1332,7 @@ bgp_import_control(struct proto *P, rte **new, ea_list **attrs UNUSED, struct li
   return 0;
 }
 
+
 static adata null_adata;	/* adata of length 0 */
 
 static ea_list *
@@ -1394,11 +1404,11 @@ bgp_update_attrs(struct bgp_proto *p, struct bgp_channel *c, rte *e, ea_list *at
 
     /* Prepend src cluster ID */
     if (src->rr_cluster_id)
-      ad = int_set_add(pool, ad, src->rr_cluster_id);
+      ad = int_set_prepend(pool, ad, src->rr_cluster_id);
 
     /* Prepend dst cluster ID if src and dst clusters are different */
     if (p->rr_cluster_id && (src->rr_cluster_id != p->rr_cluster_id))
-      ad = int_set_add(pool, ad, p->rr_cluster_id);
+      ad = int_set_prepend(pool, ad, p->rr_cluster_id);
 
     /* Should be at least one prepended cluster ID */
     bgp_set_attr_ptr(&attrs, pool, BA_CLUSTER_LIST, 0, ad);
diff --git a/proto/bgp/bgp.c b/proto/bgp/bgp.c
index 61d24f42..5e95e6b4 100644
--- a/proto/bgp/bgp.c
+++ b/proto/bgp/bgp.c
@@ -559,6 +559,10 @@ bgp_conn_leave_established_state(struct bgp_proto *p)
   BGP_TRACE(D_EVENTS, "BGP session closed");
   p->conn = NULL;
 
+  // XXXX free these tables to avoid memory leak during graceful restart
+  // bgp_free_prefix_table(p);
+  // bgp_free_bucket_table(p);
+
   if (p->p.proto_state == PS_UP)
     bgp_stop(p, 0);
 }
diff --git a/proto/ospf/rt.c b/proto/ospf/rt.c
index 054841ca..49167ceb 100644
--- a/proto/ospf/rt.c
+++ b/proto/ospf/rt.c
@@ -422,10 +422,9 @@ add_network(struct ospf_area *oa, net_addr *net, int metric, struct top_hash_ent
   if (en == oa->rt)
   {
     /*
-     * Local stub networks does not have proper iface in en->nhi
-     * (because they all have common top_hash_entry en).
-     * We have to find iface responsible for that stub network.
-     * Configured stubnets does not have any iface. They will
+     * Local stub networks do not have proper iface in en->nhi (because they all
+     * have common top_hash_entry en). We have to find iface responsible for
+     * that stub network. Configured stubnets do not have any iface. They will
      * be removed in rt_sync().
      */
 
@@ -1429,7 +1428,6 @@ ospf_ext_spf(struct ospf_proto *p)
   struct top_hash_entry *en;
   struct ospf_lsa_ext_local rt;
   ort *nf1, *nf2;
-  orta nfa = {};
   u32 br_metric;
   struct ospf_area *atmp;
 
@@ -1437,6 +1435,8 @@ ospf_ext_spf(struct ospf_proto *p)
 
   WALK_SLIST(en, p->lsal)
   {
+    orta nfa = {};
+
     /* 16.4. (1) */
     if ((en->lsa_type != LSA_T_EXT) && (en->lsa_type != LSA_T_NSSA))
       continue;
@@ -1578,6 +1578,7 @@ ospf_rt_reset(struct ospf_proto *p)
   FIB_WALK(&p->rtf, ort, ri)
   {
     ri->area_net = 0;
+    ri->keep = 0;
     reset_ri(ri);
   }
   FIB_WALK_END;
@@ -1941,9 +1942,12 @@ again1:
 	}
     }
 
-    /* Remove configured stubnets */
-    if (!nf->n.nhs)
+    /* Remove configured stubnets but keep the entries */
+    if (nf->n.type && !nf->n.nhs)
+    {
       reset_ri(nf);
+      nf->keep = 1;
+    }
 
     if (nf->n.type) /* Add the route */
     {
@@ -1999,7 +2003,7 @@ again1:
     }
 
     /* Remove unused rt entry, some special entries are persistent */
-    if (!nf->n.type && !nf->external_rte && !nf->area_net)
+    if (!nf->n.type && !nf->external_rte && !nf->area_net && !nf->keep)
     {
       if (nf->lsa_id)
 	idm_free(&p->idm, nf->lsa_id);
diff --git a/proto/ospf/rt.h b/proto/ospf/rt.h
index 959d12e9..118d09b7 100644
--- a/proto/ospf/rt.h
+++ b/proto/ospf/rt.h
@@ -84,6 +84,7 @@ typedef struct ort
   u32 lsa_id;
   u8 external_rte;
   u8 area_net;
+  u8 keep;
 
   struct fib_node fn;
 }
diff --git a/sysdep/bsd/sysio.h b/sysdep/bsd/sysio.h
index 0c5f8fbb..0e895e20 100644
--- a/sysdep/bsd/sysio.h
+++ b/sysdep/bsd/sysio.h
@@ -9,6 +9,7 @@
 #include <net/if_dl.h>
 #include <netinet/in_systm.h> // Workaround for some BSDs
 #include <netinet/ip.h>
+#include <sys/param.h>
 
 
 #ifdef __NetBSD__
@@ -179,8 +180,8 @@ sk_prepare_ip_header(sock *s, void *hdr, int dlen)
   ip->ip_src = ipa_to_in4(s->saddr);
   ip->ip_dst = ipa_to_in4(s->daddr);
 
-#ifdef __OpenBSD__
-  /* OpenBSD expects ip_len in network order, other BSDs expect host order */
+#if (defined __OpenBSD__) || (defined __DragonFly__) || (defined __FreeBSD__ && (__FreeBSD_version >= 1100030))
+  /* Different BSDs have different expectations of ip_len endianity */
   ip->ip_len = htons(ip->ip_len);
 #endif
 }
diff --git a/sysdep/linux/netlink.c b/sysdep/linux/netlink.c
index ee2cd125..554f2c97 100644
--- a/sysdep/linux/netlink.c
+++ b/sysdep/linux/netlink.c
@@ -1608,6 +1608,7 @@ nl_async_hook(sock *sk, uint size UNUSED)
 	   *  One day we might react to it by asking for route table
 	   *  scan in near future.
 	   */
+	  log(L_WARN "Kernel dropped some netlink messages, will resync on next scan.");
 	  return 1;	/* More data are likely to be ready */
 	}
       else if (errno != EWOULDBLOCK)
diff --git a/sysdep/unix/io.c b/sysdep/unix/io.c
index c8916378..6722fc69 100644
--- a/sysdep/unix/io.c
+++ b/sysdep/unix/io.c
@@ -2631,7 +2631,8 @@ io_loop(void)
 	      if (pfd[s->index].revents & (POLLHUP | POLLERR))
 		{
 		  sk_err(s, pfd[s->index].revents);
-		  goto next2;
+		  if (s != current_sock)
+		    goto next2;
 		}
 
 	      current_sock = sk_next(s);