[144207] in North American Network Operators' Group
Re: Preferring peers over customers [was: Do Not Complicate Routing
daemon@ATHENA.MIT.EDU (Jared Mauch)
Mon Sep 5 10:28:20 2011
From: Jared Mauch <jared@puck.nether.net>
In-Reply-To: <0C2D5B74-3C6D-4005-B1D1-26AACBFBD15C@ianai.net>
Date: Mon, 5 Sep 2011 10:26:18 -0400
To: "Patrick W. Gilmore" <patrick@ianai.net>
Cc: North American Operators' Group <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Sep 4, 2011, at 9:18 PM, Patrick W. Gilmore wrote:
> I would like the large networks of the world to state whether they =
prefer their customer routes over peer routes, and how. For instance, =
does $NETWORK prefer customers only when the AS path is the same, or all =
the time no matter what?
>=20
> Let's leave out corner cases - e.g. If a customer asks you, via =
communities or otherwise, to do something different. This is a poll of =
default, vanilla configurations.
>=20
> Please send them to me, or the list, with this subject line. I shall =
compile the results and post them somewhere public. If you cannot speak =
for your company, I will keep your name private.
The NTT network has a well documented local-pref policy that shows what =
is done.
You can review it on the website, including showing that the default =
local-preference is 120.
http://www.us.ntt.net/support/policy/routing.cfm
Having worked for small players that peered with other partners/networks =
in the past, not following a model of customer -> peer -> transit order =
of preference, you can create situations where someone unexpectedly is =
creating a traffic black hole.
It's not saying you can't build a better model, but this is fairly =
straightforward and provides expected results. Your customer routes =
will always be propagated to your peers. Having communities to allow =
the customer to change how their routes are propagated is valuable so =
they can 'choose their own adventure'. If someone wants to not announce =
to another provider, that is their "fault" when traffic breaks.
- Jared=
