nanog mailing list archives

Re: Dedicated Route Reflectors


From: joshua sahala <jejs+lists () sahala org>
Date: Fri, 11 Sep 2009 17:41:54 -0600


On 11 Sep, 2009, at 09:30, Serge Vautour wrote:

Hello,

We're in the process of planning for an MPLS network that will use BGP for signaling between PEs. This will be a BGP free Core (i.e. no BGP on the P routers). What are folks doing for iBGP in this case? Full Mesh? Full Mesh the Main POP PEs and Route Reflect to some outlining PEs? Are folks using dedicated/centralized Route Reflectors (redundant of course)? What about using some of the P routers as the Centralized Route Reflectors? The boxes aren't doing much from a Control Plane perspective, why not use them as Route Reflectors.


serge,

you can, and probably should, segment your mpls signalling ibgp from your internet/peering ibgp. in other words, on your pe, you configure ipv4/ipv6 bgp sessions to your peering/transit routers, then you configure mp-bgp sessions to three or four mpls vpn route reflectors. the mpls route reflectors do not participate in the actual routing of any packets (they don't set next-hop-self, only the pe routers would), their only function is to reflect the vpn signalling between disparate pe boxen.

similarly, if you have a very large number of pe routers, you can setup three or four boxes to reflect internet/customer routes...these boxes also would not route any packets, they would just reflect the non-mpls bgp sessions (they don't set next-hop-self, only the pe/ transit/peering router do).

alternately, if you have local transit/peering routers at every pe site, then you can mesh all the transit/peering routers and have the local pe routers be rr clients of that site's transit/peering routers

hth
/joshua


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