Home page logo

nanog logo nanog mailing list archives

Re: BGP Confederations
From: Robert Raszuk <raszuk () cisco com>
Date: Wed, 04 Oct 2000 19:53:26 -0700

Hi ccie10,

Have you considered reflectors ? The configuration is trival and
migration easy. Is your reason for confederations partitioning based on
the need to run multiple IGP instances in your network ? If so what IGP
are you running today (having full mesh of ibgp) and how big is the
network we are talking about here ?

I am asking as I wonder why scaling ibgp mesh with reflectors was not
chosen as the prefered option.

It's not a fun process. I've given the matter quite a lot of thought.
There are no easy ways to do this. Of course, with sufficient planning,
some scripts, a good lab environment, and a few hours of downtime, a
network can be transitioned. I don't recommend it for faint of heart. The
best candidates for a BGP Confederation design are isolated eBGP networks
(i.e. networks where AS border routers run eBGP, with no iBGP mesh) and
greenfield networks. The last network I worked with that made a successful
transition was Mindspring, AS4355, and they fell into the former category.

The big question is, how big is the network. It's a trivial transition
with 10 routers, lets say. If you have 100 fully meshed iBGP peers, I
wouldn't bet on it. Also, implement communities  - they make certain
aspects of confederation configuration much easier.

For more information on confeds, check on the NANOG web site. There are
several archived presentations on the subject.

- Dan Golding

On Wed, 4 Oct 2000, ccie10 wrote:

Is there an easy way to migrate an existing network running IBGP full mesh
to a
Condederation based configration. Any documentation that I have come across
states that current BGP configs need to be redone and all peering
relationships must torn down and rebuilt. Any addtional info/links regarding
confederations would be appreciated


  By Date           By Thread  

Current thread:
[ Nmap | Sec Tools | Mailing Lists | Site News | About/Contact | Advertising | Privacy ]