diff --git a/bgpd/bgp_attr.c b/bgpd/bgp_attr.c
index e2b6054..7a0ab56 100644
--- a/bgpd/bgp_attr.c
+++ b/bgpd/bgp_attr.c
@@ -746,78 +746,51 @@
 
   return 0;
 }
-/* Parse AS path information.  This function is wrapper of aspath_parse.
- *
- * Parses AS_PATH or AS4_PATH.
- *
- * Returns: if valid: address of struct aspath in the hash of known aspaths,
- *                    with reference count incremented.
- *              else: NULL
- *
- * NB: empty AS path (length == 0) is valid.  The returned struct aspath will
- *     have segments == NULL and str == zero length string (unique).
- */
-static struct aspath *
+
+/* Parse AS path information.  This function is wrapper of
+   aspath_parse. */
+static int
 bgp_attr_aspath (struct peer *peer, bgp_size_t length, 
-		 struct attr *attr, u_char flag, u_char *startp, int as4_path)
+		 struct attr *attr, u_char flag, u_char *startp)
 {
-  u_char require ;
-  struct aspath *asp ;
+  bgp_size_t total;
 
-  /* Check the attribute flags                                          */
-  require = as4_path ? BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS
-                     :                          BGP_ATTR_FLAG_TRANS ;
+  total = length + (CHECK_FLAG (flag, BGP_ATTR_FLAG_EXTLEN) ? 4 : 3);
 
-  if ((flag & (BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS)) != require)
+  /* Flag check. */
+  if (CHECK_FLAG (flag, BGP_ATTR_FLAG_OPTIONAL)
+      || ! CHECK_FLAG (flag, BGP_ATTR_FLAG_TRANS))
     {
-      const char* path_type ;
-      bgp_size_t total;
-
-      path_type = as4_path ? "AS4_PATH" : "AS_PATH" ;
-
-      if (!CHECK_FLAG(flag, BGP_ATTR_FLAG_TRANS))
       zlog (peer->log, LOG_ERR, 
-            "%s attribute flag isn't transitive %d", path_type, flag) ;
-
-      if ((flag & BGP_ATTR_FLAG_OPTIONAL) != (require & BGP_ATTR_FLAG_OPTIONAL))
-        zlog (peer->log, LOG_ERR,
-            "%s attribute flag must %sbe optional %d", path_type,
-            (flag & BGP_ATTR_FLAG_OPTIONAL) ? "not " : "", flag) ;
-
-      total = length + (CHECK_FLAG (flag, BGP_ATTR_FLAG_EXTLEN) ? 4 : 3);
-
+	    "As-Path attribute flag isn't transitive %d", flag);
       bgp_notify_send_with_data (peer, 
 				 BGP_NOTIFY_UPDATE_ERR, 
 				 BGP_NOTIFY_UPDATE_ATTR_FLAG_ERR,
 				 startp, total);
-
-      return NULL ;
-    } ;
-
-  /* Parse the AS_PATH/AS4_PATH body.
-   *
-   * For AS_PATH  peer with AS4 => 4Byte ASN otherwise 2Byte ASN
-   *     AS4_PATH 4Byte ASN
-   */
-  asp = aspath_parse (peer->ibuf, length,
-               as4_path || CHECK_FLAG (peer->cap, PEER_CAP_AS4_RCV), as4_path) ;
-
-  if (asp != NULL)
-    {
-      attr->flag |= ATTR_FLAG_BIT (as4_path ? BGP_ATTR_AS4_PATH
-                                            : BGP_ATTR_AS_PATH) ;
+      return -1;
     }
-  else
+
+  /*
+   * peer with AS4 => will get 4Byte ASnums
+   * otherwise, will get 16 Bit
+   */
+  attr->aspath = aspath_parse (peer->ibuf, length, 
+                               CHECK_FLAG (peer->cap, PEER_CAP_AS4_RCV));
+
+  /* In case of IBGP, length will be zero. */
+  if (! attr->aspath)
     {
       zlog (peer->log, LOG_ERR, "Malformed AS path length is %d", length);
-
-      /* TODO: should BGP_NOTIFY_UPDATE_MAL_AS_PATH be sent for AS4_PATH ??  */
       bgp_notify_send (peer, 
 		       BGP_NOTIFY_UPDATE_ERR, 
 		       BGP_NOTIFY_UPDATE_MAL_AS_PATH);
-    } ;
+      return -1;
+    }
 
-  return asp ;
+  /* Set aspath attribute flag. */
+  attr->flag |= ATTR_FLAG_BIT (BGP_ATTR_AS_PATH);
+
+  return 0;
 }
 
 static int bgp_attr_aspath_check( struct peer *peer, 
@@ -875,6 +848,21 @@
 
 }
 
+/* Parse AS4 path information.  This function is another wrapper of
+   aspath_parse. */
+static int
+bgp_attr_as4_path (struct peer *peer, bgp_size_t length, 
+		 struct attr *attr, struct aspath **as4_path)
+{
+  *as4_path = aspath_parse (peer->ibuf, length, 1);
+
+  /* Set aspath attribute flag. */
+  if (as4_path)
+    attr->flag |= ATTR_FLAG_BIT (BGP_ATTR_AS4_PATH);
+
+  return 0;
+}
+
 /* Nexthop attribute. */
 static int
 bgp_attr_nexthop (struct peer *peer, bgp_size_t length, 
@@ -1613,12 +1601,10 @@
 	  ret = bgp_attr_origin (peer, length, attr, flag, startp);
 	  break;
 	case BGP_ATTR_AS_PATH:
-          attr->aspath = bgp_attr_aspath (peer, length, attr, flag, startp, 0);
-          ret = attr->aspath ? 0 : -1 ;
+	  ret = bgp_attr_aspath (peer, length, attr, flag, startp);
 	  break;
 	case BGP_ATTR_AS4_PATH:
-          as4_path = bgp_attr_aspath (peer, length, attr, flag, startp, 1);
-          ret = as4_path  ? 0 : -1 ;
+	  ret = bgp_attr_as4_path (peer, length, attr, &as4_path );
 	  break;
 	case BGP_ATTR_NEXT_HOP:	
 	  ret = bgp_attr_nexthop (peer, length, attr, flag, startp);