BGP Configuration Problem

Fri Nov 8 13:46:03 UTC 1996

Make sure router B doesn't do auto-summary in BGP.

-- jli

> 
> On Thu, 07 Nov 1996 22:21:15 -0500, lambert at 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 at netINS.net       *   This space for rent pending        *
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