IBGP Question --- Router Reflector or iBGP Mesh

Erik Haagsman erik at we-dare.net
Tue Jan 11 10:40:04 UTC 2005

On Tue, 2005-01-11 at 02:03, Eric Kagan wrote: 
> Does anyone have any input on when this does make sense ?  We have 3 Main IP
> pops with upstream BGP at each and 4 internal BGP sessions.  I am looking to
> add 2 new routers so there will be about 7 sessions on each border router.

This seems to be a case where it does make sense. If you set up two
route reflectors you could do with providing each border router only two
iBGP links. You could for instance split your network into two logical
clusters with 1 route reflector each and link the two route reflectors
so they bounce routes to each other as well and provide your border
routers with BGP links to both for good redundancy and a less complex
network layout. Transition isn't that hard really, assuming your border
routers already have iBGP links to the routers that will become
reflectors it's a matter of configuring the reflectors right and making
sure the border routers are connected as route reflector clients, and
then start tearing down the remaining sessions. This isn't the only
possible option using route reflector and full/partial mesh ofcourse and
you'll have to decide what works for your network, but route reflectors
would seem to be useful in your set-up.


Erik Haagsman
Network Architect
We Dare BV
tel: +31(0)10 7507008
fax:+31(0)10 7507005

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