On 2010-04-08, at 12:42, Elmar K. Bins wrote: > [email protected] (Joe Abley) wrote: > >>> 1) Is a private AS typically used for the exchange side of the session? >> No. Also many exchange points do not run route servers at all, and expect >> participants to build bilateral BGP sessions directly between each other. > > ...which is a shame. Routeservers in place gives you a nice benefit > upon hooking up to the exchange and before you have even found out > who is on the grid (anyone have a list for NOTA?).
I've never had a problem getting a participant list for NOTA from Terremark. One down-side of route servers on a shared exchange fabric is that the layer-2 path through the exchange for the BGP sessions does not always match the layer-2 path through the exchange for traffic. This means that AS1 might continue to learn AS2's routes through the route server even though there's a layer-2 problem that prevents AS1 and AS2's peering routers from talking directly to each other. Hilarity may result. I've never seen such a problem on small exchanges where the layer-2 fabric is simple, but I have seen it more than once on larger, more complicated exchanges. My personal preference is to focus peering energy on bilats, and not to rely on a route server. But I understand the savings in opex that route servers can provide on busy exchanges. Joe
