BGP Configuration Problem

Rob Liebschutz rob at rjl.com
Fri Nov 8 16:17:51 UTC 1996


> > 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.
> 
> Even if it isn't the best route, you should see the table of choices 
> (in a Crisco) if you do 'sho ip bgp x.y.z.0'.  You'll only see the most
> specific choices that match with that - you could also do a 'sho ip bgp' and 
> watch (presumably 10/8 should be near the top) for 10.1.64.0's range to show up
> and see what choices are presented.

How about:
show ip bgp 10.1.0.0 255.255.0.0 longer-prefixes






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