[79476] in North American Network Operators' Group
Re: AS prepending
daemon@ATHENA.MIT.EDU (Pete Templin)
Fri Apr 8 11:36:05 2005
Date: Fri, 08 Apr 2005 10:35:40 -0500
From: Pete Templin <petelists@templin.org>
To: Philip Lavine <source_route@yahoo.com>
Cc: nanog@nanog.org
In-Reply-To: <20050408150441.89045.qmail@web51909.mail.yahoo.com>
Errors-To: owner-nanog@merit.edu
Philip Lavine wrote:
> Update:
>
> I am prepending my AS 3 times to the un-preferred ISP.
> Both ISP's are my peers. The un-preferred ISP claims
> the see my advertisement yet they do not add it to
> their routing table (suggests filtering??). They claim
> all the filtering they are doing is based on the
> networks I told them over the phone that I was using
> with that AS.
I have heard of providers who filter on AS path, and filter in such a
way that more than N prepends (for varying values of N) causes the
route(s) to be rejected. This could potentially be your problem. If
they do soft-reconfig in on their customer sessions, they may see the
route but filter it out.
pt
