[65772] in North American Network Operators' Group
Re: AS Path Loops in practice ?
daemon@ATHENA.MIT.EDU (Niels Bakker)
Tue Dec 9 09:13:56 2003
Date: Tue, 9 Dec 2003 15:13:12 +0100
From: Niels Bakker <niels=nanog@bakker.net>
To: nanog@merit.edu
Mail-Followup-To: nanog@merit.edu
In-Reply-To: <08DE5319-2A2C-11D8-923F-000A95972A60@hamsterjam.net>
Errors-To: owner-nanog-outgoing@merit.edu
* bcrocker@hamsterjam.net (Ben Crocker) [Tue 09 Dec 2003, 10:44 CET]:
[..]
> In our case a customer using BGP to our network from the same AS in two
> locations but not running an IGP between them (our's is not to reason
> why and all that)
A commonly accepted definition of AS is as follows:-
| An Autonomous System (AS) is a connected group of one or more IP
| prefixes run by one or more network operators under a *single* and
| clearly defined routing policy.
[emphasis mine]
One cannot have discontiguous networks in the same ASN. It's pretty
simple: two routing policies, two ASes, two ASNs. Unfortunately you
weren't able to convince your customer of this.
As you showed, it can be configured. More power to Vendor J for giving
us all the choice to do so, but that still rarely makes it a good idea.
-- Niels.
--
the generation that used acid to escape reality
is now using antacid to deal with reality
