diff --git a/bgpd/bgp_community.c b/bgpd/bgp_community.c
--- a/bgpd/bgp_community.c
+++ b/bgpd/bgp_community.c
@@ -320,18 +320,30 @@ community_intern (struct community *com)
 void
 community_unintern (struct community *com)
 {
-  struct community *ret;
+  struct community *hashed;
 
   if (com->refcnt)
     com->refcnt--;
 
-  /* Pull off from hash.  */
   if (com->refcnt == 0)
     {
-      /* Community value com must exist in hash. */
-      ret = (struct community *) hash_release (comhash, com);
-      assert (ret != NULL);
-
+      /* For sake of simplicity in routemap code, we allow
+       * unintern to be called on communities which need not have been
+       * interned. Cost is double hash lookup in some cases.
+       */
+      
+      /* Is there a hash reference? */
+      if (hash_lookup (comhash, com))
+        {
+          hashed = (struct community *) hash_release (comhash, com);
+          assert (hashed != NULL);
+          
+          /* com could match value of hashed, but not be same 
+           * struct
+           */
+          if (hashed != com)
+            community_free (hashed);
+        }
       community_free (com);
     }
 }
diff --git a/bgpd/bgp_routemap.c b/bgpd/bgp_routemap.c
--- a/bgpd/bgp_routemap.c
+++ b/bgpd/bgp_routemap.c
@@ -1195,7 +1195,7 @@ route_set_community (void *rule, struct 
   struct community *new = NULL;
   struct community *old;
   struct community *merge;
-
+  
   if (type == RMAP_BGP)
     {
       rcs = rule;
@@ -1215,13 +1215,17 @@ route_set_community (void *rule, struct 
       if (rcs->additive && old)
 	{
 	  merge = community_merge (community_dup (old), rcs->com);
+	  community_unintern (old);
 	  new = community_uniq_sort (merge);
 	  community_free (merge);
 	}
       else
 	new = community_dup (rcs->com);
-
-      attr->community = new;
+      
+      /* we rely on fact that new is the result of a dup and hence
+       * community_intern will free it.
+       */
+      attr->community = community_intern (new);
 
       attr->flag |= ATTR_FLAG_BIT (BGP_ATTR_COMMUNITIES);
     }