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Thread Index [isp-bgp] Re: Zebra as Route Reflector
Just a Q: Have you tried configuring and maintaining a backbone with 500 routers in IBGP mesh? Route reflectors come in handy here -hc -- Sincerely, Haesu C. TowardEX Technologies, Inc. WWW: http://www.towardex.com E-mail: haesu@... Cell: (978) 394-2867 On Tue, Jul 29, 2003 at 09:12:57PM -0700, Pedro R Marques wrote: > On Tue, 2003-07-29 at 01:54, Tulip Rasputin wrote: > > > > > I am not sure if the RRs are always supposed to be in the traffic path. > > > > ---[A]\----------- > > \ | > > [RR]---- [C] > > / | > > / | > > ---[B]----------- > > > > A, B and C are 3 clients of the RR. RR here reflects the routes from A and B to C - but doesnt > > come anywhere in the data forwarding path. C can throug some IGP cloud can send data directly to A > > and B. > > > > Isnt this possible? > > Possible it is. > It is also possible to mess it up :-) And i just wanted to point that > out. For instance if the IGP distances above all are the same, the RR > will perform path selection based on say router-id... However if B is > closer to C than to A (that is how i interpret your diagram) this may > not be the desired result. > > I guess the answer to your question depends on topology, metrics, etc. > > > This is then a limitation of the RR. Shouldn't we be addressing it? Lately there have been some > > proposals in the IETF to advertise multiple BGP routes. Will that not help here? > > The original purpose of RRs is to aggregate routing information. If you > do not aggregate information (via selecting a subset of available > paths), then you defeat the purpose. > > In reality, it seems to me that often people use reflection more as a > configuration aid. But that is probably the wrong tool for the job. > > It was originally thought that the number of TCP sessions in a mesh > could be a problem. My opinion is that this is not really an issue. iBGP > meshes w/ several hundreds of routes work just fine. > > One could think of a route reflector-like box that doesn't always > advertise just one path and doesn't always advertise all. > But that is a very significant change from the current model. > > regards, > Pedro. > > > ------------------------ANNOUNCEMENT--------------------------------- > --------------------------------------------------------------------- > ISPCON FALL 2003 - Santa Clara Convention Center > October 20-22 - The Definitive Event Wired and Wireless ISPs > www.ispcon.com > ---------------------------------------------------------------------- > ---------------------------------------------------------------------- > > ------------------------ANNOUNCEMENT--------------------------------- --------------------------------------------------------------------- ISPCON FALL 2003 - Santa Clara Convention Center October 20-22 - The Definitive Event Wired and Wireless ISPs www.ispcon.com ---------------------------------------------------------------------- ----------------------------------------------------------------------
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