On Tue, Feb 05, 2013 at 10:34:02AM +0000, Stuart Henderson wrote: > On 2013-02-04, Eduardo Meyer <[email protected]> wrote: > >> On 02/04/2013 03:59 PM, Eduardo Meyer wrote: > >> > Hello, > >> > > >> > I am facing a strange behavior, > >> > > >> > I have the following scenario > >> > > >> > eBGP1<->iBGP1<->iBGP2<->iBGP3<->eBGP2 > >> > >> iBGP must be fully meshed, a session between iBGP1 and iBGP3 is > >> missing. > > > > Really? It's difficult for me in this environment, do I have another option? > > This doesn't mean that they need to be directly connected; iBGP sessions > can be run over multiple hops by default. It just means you need neighbour > configs for 1<>2, 1<>3, 2<>3. > > You could use a route reflector as others suggested but it's a bit > much for this setup imo; it will be a critical part of the network so > you'll probably want a redundant pair. These come into their own when the > number of routers goes up.
It should be possible to make all routers route-reflectors and not do a full mesh but route-reflector setups are not inherently stable. In some setups they can result in a unstable network. Especially when adding redundancies to setups (by additional RRs or additional iBGP links) it is possible to end up with a not converging network which is fun fun fun... In general if you have less than a handfull bgp router us a full mesh. The pain of fiddeling with RR is not worth the few sessions you save. -- :wq Claudio
