[6023] in North American Network Operators' Group
Re: BGP Configuration Problem
daemon@ATHENA.MIT.EDU (Jian Li)
Fri Nov 8 09:11:34 1996
From: Jian Li <jli@hq.si.net>
To: jcgreen@netins.net (Jon Green)
Date: Fri, 8 Nov 1996 08:46:03 -0500 (EST)
Cc: lambert@psc.edu, nanog@merit.edu
In-Reply-To: <199611080334.VAA26967@worf.netins.net> from "Jon Green" at Nov 7, 96 09:34:45 pm
Make sure router B doesn't do auto-summary in BGP.
-- jli
>
> On Thu, 07 Nov 1996 22:21:15 -0500, lambert@psc.edu writes:
> >
> >We are having a BGP configuration problem which looks trivial but is not
> >working the way we expect. I'm going to throw myself on the mercy of
> >the court and ask for help.
> >
> >There are three routers A, B and C. These are in ASa, ASb and ASc,
> >respectively. B imports 10.1.64/19 from A and 10.1/16 from C. What
> >we were expecting was for B's route to the /19 to be via A, just because
> >this is the more specific route. However, the only route (both in the
> >BGP and routing tables on B) is for the entire /16 via C.
> >
> >I have a hunch that what is happening is that B is saying "gee, I can
> >get to the entire /16 by going through C, so why bother with A". If I'm
> >not mistaken, this can be fixed by introducing local_pref for both peers.
> >Could someone please comment on this?
>
>
> If B is hearing the route from A, it should at least show up in the BGP
> table. The behavior that you expect is what it should be doing; it
> sounds to me like B is not even hearing the BGP announcement from A.
> Check how you have accept policies configured on B, and how you have
> announce policies configured on A, and when in doubt, call your router
> vendor for help. :)
>
> -Jon
>
> -----------------------------------------------------------------
> * Jon Green * *
> * jcgreen@netINS.net * This space for rent pending *
> * Finger for Geek Code/PGP * me thinking up a witty quote. *
> * #include "std_disclaimer.h" * *
> -------------------------------------------------------------------------
>
