From: Peter van Oene (pvo@usermail.com)
Date: Tue Nov 05 2002 - 10:48:03 GMT-3
At 11:23 AM 11/4/2002 -0800, Jim Terry wrote:
>Hi all,
>
>I have another BGP question on an NBMA network.
BGP runs over TCP and so long as you have IP reach ability, the L2 topology
shouldn't matter
>All spokes and hub are running OSPF and there is proper connectivity.
>The hub is one AS and the spokes are in a different AS.
I must say this is a bizarre setup.
>I can ping the loopbacks for all OSPF advertised interfaces but cannot ping
>the loopbacks that are advertised in BGP with the network command. It does
>not matter if I am pinging spoke to spoke(same AS) or spoke to hub(different
>AS)
As with your last example, did you verify:
a) appropriate routes are in the bgp table (show ip bgp)
b) BGP next-hop is reachable
c) appropriate routes are in the local rib (show ip route)
Keep in mind this is bi-directional and you'll need to make sure that your
destinations can respond to the source of your pings.
>I do have in BGP the next-hop-self from the hub to one spoke. That one
>spoke is the route-reflector for the other spokes. Spoke to spoke
>connectivity is only via the serial links in the NBMA through the hub.
Next-hop Self is an IBGP function and does not relate to EBGP peering. In
EBGP, you must reset next-hop. Are your spoke to spoke peerings
established? What do the adj-rib in/outs look like (show ip bgp neighbor
x.x.x.x. advertised-routes / received routes)
>Does anyone have any ideas?
You really need to step through a logical debugging process here much like
you would any reach ability problems. BGP adds the additional steps of
verifying peering, route advertisement / reception, BGP next-hop
resolution, and sync if you have it enabled.
>JT
Pete
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