From: Facundo Musante (musante@xxxxxxxxxxxxxxxxxxxxx)
Date: Wed Dec 27 2000 - 23:42:47 GMT-3
Mike,
On the bgp table in R3, check the next hop address for the routes that BGP
learned but are not on the forwarding table (sh ip route).
The router won't consider any "BGP learned" route as valid if it doesn't
know how to get to the next hop address...pretty reasonable behavior ;-)
Make sure the next hop is reachable.
"No Synch" won't help you with this one. Synchronization verifies that the
announcing router knows the route via IGP before it announces the route
through BGP.
The idea of the synch is avoiding announce a route that you won't be able to
handle through the IGP AS. On the other hand, if all the involved routers
are running BGP, you don't rely on any IGP and you can remove synch.
Hope it helps,
FM
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
> Michael King
> Sent: Wednesday, December 27, 2000 7:22 PM
> To: ccielab@groupstudy.com
> Subject: BGP and the route table
>
>
> What are the conditions for a route in the BGP route
> table to make it to the ip route table?
>
> I have 3 AS's: AS1, AS2, and AS3. AS1 has EBGP to
> AS2 and AS2 has EBGP to AS3 ( AS1-->AS2-->AS3). To
> further simplify, each AS has 1 router.
>
> AS1 is advertising directly connected routes to AS2.
> AS2's BGP table and IP route table have all BGP
> advertised routes from AS1. AS3 only has routes in
> BGP table and NOT IP route table. I have turned off
> synchronization on all routers but still can't get
> routes in AS3's IP route table.
>
> Mike
>
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