[nsp] ebgp vs ebgp multihop

Everton da Silva Marques everton at lab.ipaccess.diveo.net.br
Wed Mar 26 09:42:25 EST 2003

On Wed, Mar 26, 2003 at 01:42:10PM +1100, Dmitri Kalintsev wrote:
> On Tue, Mar 25, 2003 at 01:01:28PM +0100, Nipper, Arnold wrote:
> > Simple rule: if you don't have to do it don't do it. I only came across
> > multi-hop in the following situtations:
> > 
> >  + direct hops are not capable of running bgp (or bgp with full tables)
> >  + bundeling of links
> >  + for monitoring purposes
> + Next hop rewrite to something non-directly-connected.

Also, it may be of note that:

One usually expects a BGP session to close and
to withdraw routes when the underlying directly
connected links fail.

Depending on the AS peering-topology and routing policy,
a BGP multi-hop session could remain established
through other path than the expected one
(the directly connected network).

This issue does not exist for one-hop-BGP.

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