From: Paul Lalonde (plalonde2@cogeco.ca)
Date: Thu Apr 24 2003 - 17:22:33 GMT-3
Doug,
Redistribute the BGP routes from each BGP speaker into a different routing
protocol (not OSPF) and redistribute between the IGPs to ensure each BGP
speaker learns of the routes it is supposed to advertise via IGP. Is there
any requirement stating additional routing protocols cannot be used?
Hope this helps,
Paul
----- Original Message -----
From: "DougAtHome" <dcalton@fuse.net>
To: "ccielab" <ccielab@groupstudy.com>
Sent: Thursday, April 24, 2003 3:08 PM
Subject: BGP Synchronization
> Time is getting short for me. I have tried in a couple of lab scenarios,
> including Solie's "Unnamed" lab, to implement Route Reflectors with
> Synchronization turned on, where OSPF is the IGP. In both scenarios, a
BGP RR
> Client will not select IBGP routes as "best" because it will not
synchronize.
> Ultimately, this is due to the fact that Cisco mandates that the BGP and
OSPF
> source Router IDs match. Normally, this would not be a problem, but
> apparently, IF the Route Reflector is NOT the redistribution router, route
> reflection overwrites the BGP Router ID for the reflected routes with its
own
> Router ID. Here's a diagram of the situation:
>
> R4
> |
> |
> R1 -------R2 ---------R3
>
> R2 in my diagram has an EBGP session with router R4, and IBGP session with
R3.
> R3 is a Route Reflector, listing both R2 and R1 as clients. BGP is
> redistributed into OSPF at R2, of course, since this is where the external
> routes are introduced. R3 synchronizes fine, but R1 shows all BGP routes
as
> unsynchronized.
>
> I have tried various things, including Cluster IDs (couldn't make that
config
> "stick") and NOT making R1 a client, but still the same result - R3
replaces
> the original Router ID source with its own Router ID, causing R1 to reject
the
> IGP route with the OSPF Router ID as a non match.
>
> I have searched the archives of this and other news groups and found no
> solution. The closest I came was a long discourse that ended with using
> Confederations.
>
> I guess I have two questions here:
> 1. What am I not doing that might make this thing work?
> 2. Why is Cisco so fussy about matching OSPF and BGP router ids anyway?
This
> seems to contradict the behavior of Route Reflection, and makes
> Synchronization not only out of date, but non-functional to boot.
>
> Yeah, I know nobody uses Synchronization these days, but I'm studying for
the
> lab (Sunday's the day for me =o... )
This archive was generated by hypermail 2.1.4 : Thu May 01 2003 - 13:36:05 GMT-3