[c-nsp] Should the AS # listed under the BGP AGGREGATOR attribute be the same as the AS # used to bring up a bgp session in a multiple VRF/AS router? Or the global routing table AS #?

[David Freedman]

> Do you feel it should be leaking out the global/private AS like this?

> I looked at RFC4271, and although it's not entirely clear to me, I
> believe this value should be the identifier used to bring up the BGP
> session with the peer.  However I suppose "Should" means optional in
> RFC-sense?

See RFC2119:

"SHOULD   This word, or the adjective "RECOMMENDED", mean that there
   may exist valid reasons in particular circumstances to ignore a
   particular item, but the full implications must be understood and
   carefully weighed before choosing a different course."


I can't see a reason why this would cause a problem, this is an optional
transitive and really is for informational purposes, saying that, if
your implementation recognises this attribute, it should at least do a
*syntactic* correctness check on it (but I can't see private ASNs
failing this for any valid reason)

Dave.