Subject: RE: INFORM proposal and MP-BGP (RFC 2858)

From: "Abarbanel, Benjamin" <[email-masked]>
Date: Wed, 10 Jul 2002 17:04:50 -0400

> >>  btw: If a BGP speaker, receives an inform that claims that it is
> >> sending an NLRI that in fact it is not configured to send what is
> >> the suggested behaviour ? I'd be tempted by default to reset the
> >> session since the peer clearly doesn't know what it is talking
> >> about.
>  
> > Could we not fall into this kind of race condition after session
> > resets?
> 
> It would not be of the same session, correct... ? session implies a
> TCP socket. If you do have a close, there is an implicit sequencing
> event and no confusion with previous messages.
> 
But the potential for the race condition with the new session is still 
there. If its not a fluky timing problem it might reappear, if it was fluky
it will go away. My only point is, if we were gracefull the first time it 
happened we would have told the offending peer without dropping his routes
and
perhaps it could correct the error and renegotiate the capabilities and
stabilize the problem without a network outage.

Ben

---

From: Pedro Roque Marques <[email-masked]>
Date: Wed, 10 Jul 2002 14:24:04 -0700 (PDT)

Abarbanel, Benjamin writes:

>> 
> But the potential for the race condition with the new session is
> still there.

I'm sorry but i really disagree with your statement. It would also
appear to me that if that was the truth we would have bigger issues than
the one we are discussing...

Would you please detail, under what scenario(s) you can have data from
an old BGP session being accepted as valid in a new BGP session ?

Due to the fact that these are 2 different TCP sessions, that would
require that TCP itself accepts the packet of an old session... to my
knowledge it is not commonly known for TCP to exhibit such a problem. TCP
in fact as a series of mechanisms designed to address this issue.

Of course, it could always be that i'm misinterpreting your statement,
case in which i would apologize and ask for a clarification.

regards,
  Pedro.