On Thu, Dec 11, 2008 at 01:28:46PM +0100, bjorn@mork.no wrote:
No you can't rely on that. But still, RFC4271 doesn't seemt to allow ignoring it. Which must be a bug in the RFC, or my reading of it. Hopefully the latter. Great if someone could correct the interpretation below.
IMHO, an optional transitive attribute with the partial bit set should not cause session tear-down, since the attribute is forwarded across one or more routers not handling it and therefore not filtering it.
However, RFC4271 does not make such an exception for optional + transitive + partial AFAICS: [..... copy/paste deleted .....] Which basically means that you can take down every RFC-compliant 4-byte ASN honouring router today by injecting a bogus AS4_PATH attribute into the mostly 2-byte-ASN-only Internet...
Or did I miss something? I certainly hope I did.
this was brought up in the IETF IDR mailing list today. i've attached the response from that thread that addresses your reading of the RFC. -- bill