Subject: [Idr] RE: Obscure 4-byte AS implementation question

From: "Kaliraj Vairavakkalai" <[email-masked]>
Date: Mon, 20 Aug 2007 16:23:20 +0530

Quaizar, Enke : 

> Note that a valid AS_CONFED_SEQUENCE or AS_CONFED_SET path segment 
> SHALL be prepended if it is either the leading path segment or 
> adjacent to a path segment that is prepended.

It was a bit confusing to us what this statement from RFC-4893 exactly
meant. So please clarify.

Does it mean that - 

"While making a consolidated-AS-path out of a four-byte(new) and
two-byte(old) AS-path-attributes received in a BGP-update, an ASCONF_SEQ
or ASCONF_SET appearing in the old-AS-path before the first
non-confed-segment should be prepended to the consolidated-AS-path.

Any AS_CONF_SEQ or AS_CONF_SET appearing in mid of non-confed-segment
entries in the old-AS-path should be ignored and not included in the
consolidated-AS-path."

But I think confed-segments, in the first-place, cannot occur in between
non-confed-segments in an ASpath. So I could be missing something? 

Could you please clarify what the above statement implies? 

Kaliraj 

_______________________________________________
Idr mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/idr