[109226] in North American Network Operators' Group
Re: On the subject of multihoming
daemon@ATHENA.MIT.EDU (Scott Doty)
Wed Nov 12 12:18:20 2008
Date: Wed, 12 Nov 2008 09:18:05 -0800
From: Scott Doty <scott@sonic.net>
To: NANOG list <nanog@nanog.org>
In-Reply-To: <4910B14B.9010108@thewybles.com>
Errors-To: nanog-bounces@nanog.org
[ resent to list, was sent from the wrong address -sd ]
Charles Wyble wrote:
> I'm working on a small experiment which utilizes multiple outbound
> links (in the experiments case multiple consumer 3G connections [to 2
> Sprint/2 Verizon/1 AT&T], Time Warner Cable Modem and an SBC Global
> DSL connection.
>
> What is the best way to do outbound traffic engineering? I would like
> to be able to determine the best path possible and send traffic out
> the appropriate link.
Not sure if this is useful, but I thought I'd contribute a point on the
curve...
from NANOG 9:
http://www.academ.com/nanog/feb1997/multihoming.html
Obquote: from Paul Vixie's presentation,
from Stan Barber's notes, here is the "meat of the matter":
_ _ _ _ _ _ _
Per-interface Default Route
* BSD TCP binds outbound route to PCB on SYN-ACK
* Our trick: remember the inbound interface identity from the SYN
* Each interface has its own "default route"
* For outbound TCP and all UDP, a normal default is also needed.
_ _ _ _ _ _ _
Hope that helps...
-Scott
