[110513] in North American Network Operators' Group
Re: Single carrier multi-circuit asynchronous routing issue
daemon@ATHENA.MIT.EDU (=?ISO-8859-1?Q?Anders_Lindb=E4ck?=)
Wed Jan 7 16:00:38 2009
In-Reply-To: <20090107200556.GJ56621@burnout.tpb.net>
From: =?ISO-8859-1?Q?Anders_Lindb=E4ck?= <list-only@dnz.se>
Date: Wed, 7 Jan 2009 22:00:28 +0100
To: Niels Bakker <niels=nanog@bakker.net>
Cc: nanog@nanog.org
Errors-To: nanog-bounces@nanog.org
On 7 jan 2009, at 21.05, Niels Bakker wrote:
> * aaron.millisor@bright.net (Aaron Millisor) [Wed 07 Jan 2009, =20
> 20:53 CET]:
> [..]
>> If I were to prepend the network 1.1.1.0 to come in on 'sprint 1', =20=
>> but have a route to 2.2.2.0 via 'sprint 2' so that traffic comes =20
>> in on one circuit but returns on the other, routing is broken. If =20
>> I change my route so that packets directed to 2.2.2.0 return on =20
>> the same circuit that the traffic is received on, everything works =20=
>> fine.
>
> You might be running into uRPF (unicast reverse path forward =20
> verification).
>
>
> -- Niels.
>
Strict-mode uRPF will couse this, I am sure sprint support can help =20
you with it..
------------------------------
Anders Lindb=E4ck
anders.lindback@dnz.se
