[Idr] AS Number in TLV 512 (rfc7752bis / draft-ietf-lsvr-bgp-spf)

[Alvaro Retana <[e-mail]>]

Ketan:

Hi!

While reviewing draft-ietf-lsvr-bgp-spf I came across this definition
of AS for TLV 512:

   Autonomous System:  Opaque value (32-bit AS Number).  This is an
   optional TLV.  The value SHOULD be set to the AS Number associated
   with the BGP process originating the link-state information.  An
   implementation MAY provide a configuration option on the BGP-LS
   Producer to use a different value; e.g., to avoid collisions when
   using private AS numbers.


The text doesn't require the ASN to be the same as what is on the BGP
OPEN.  It even let's any ASN be used, which could result in other
collisions or confusion. :-(

This definition was in rfc7752, and I don't remember what the
justification was for it, do you?

It seems to me that using the BGP-LS Instance-ID as a differentiator
of the origin domain would solve any issues related to multiple
autonomous systems with the same ASN -- in line with the
recommendation for IGPs.  It would also allow the definition above to
say that the "value SHOULD be set to the AS Number associated with the
BGP process originating...".


Thoughts?

Thanks!

Alvaro.