BGP Configuration Problem

> 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's range to show up
and see what choices are presented.

How about:
show ip bgp longer-prefixes