[110510] in North American Network Operators' Group
Re: Single carrier multi-circuit asynchronous routing issue
daemon@ATHENA.MIT.EDU (Niels Bakker)
Wed Jan 7 15:06:04 2009
Date: Wed, 7 Jan 2009 21:05:56 +0100
From: Niels Bakker <niels=nanog@bakker.net>
To: nanog@nanog.org
Mail-Followup-To: nanog@nanog.org
In-Reply-To: <49650835.8090308@bright.net>
Errors-To: nanog-bounces@nanog.org
* aaron.millisor@bright.net (Aaron Millisor) [Wed 07 Jan 2009, 20:53 CET]:
[..]
>If I were to prepend the network 1.1.1.0 to come in on 'sprint 1', but
>have a route to 2.2.2.0 via 'sprint 2' so that traffic comes in on one
>circuit but returns on the other, routing is broken. If I change my
>route so that packets directed to 2.2.2.0 return on the same circuit
>that the traffic is received on, everything works fine.
You might be running into uRPF (unicast reverse path forward
verification).
-- Niels.
