eBGP Multihop

Fri Sep 10 05:06:51 UTC 2010

On 2 Sep 2010, at 5:30 PM, Graham Beneke wrote:

> I have been asked to investigate moving an entire network to multi-hop on all the eBGP sessions. Basically all upstreams, downstreams and peers will eBGP with a route reflector located in the core. This RR will be some kind of quagga or similar box. The dev guys want to be able to poke at the BGP feeds directly and do *magic* that standard router aren't capable of.
> 
> My gut feel is that this is a bad idea. Besides anything else it makes sane link state detection very challenging - especially where we have multiple sessions with a peer.
> 
> Is their any BCP or operational experience that agrees or disagrees with my gut. ;-)
> 
> -- 
> Graham Beneke

Even in lab environments I would say that eBGP multihop is a bad idea. Production networks that try to make money should not embark on such a mission. Trust your gut :)

If some box wants to take a feed of routes, it should just iBGP peer with your RRs. 

Truman