[58487] in North American Network Operators' Group
Re: BGP Path Filtering
daemon@ATHENA.MIT.EDU (Jay Ford)
Fri May 16 00:24:19 2003
Date: Thu, 15 May 2003 23:23:30 -0500 (CDT)
From: Jay Ford <jay-ford@uiowa.edu>
Reply-To: Jay Ford <jay-ford@uiowa.edu>
To: Mark Radabaugh <mark@amplex.net>
Cc: nanog@merit.edu
In-Reply-To: <004801c31b52$f4994720$086df640@amplex.net>
Errors-To: owner-nanog-outgoing@merit.edu
On Thu, 15 May 2003, Mark Radabaugh wrote:
> I'm having a hard time finding best practices for filtering outbound bgp
> announcements when providing transit to bgp-speaking customers. While we
> currently multi-home to several providers it appears we will soon need to
> provide transit for customers with their own AS's.
I like using BGP communities:
o filter announcements you receive from downstreams based on your
criteria of choice
o set a specific BGP community (yourAS:whatever) on announcements which
are to be propagated to various places (upstream providers, etc.)
o do output filtering based on the communities you set
Make sure you clear yourAS:whatever in announcements from your BGP peers.
You can use this same technique for prefixes you originate, so that all your
outbound BGP filtering is based on communities.
________________________________________________________________________
Jay Ford, Network Engineering Group, Information Technology Services
University of Iowa, Iowa City, IA 52242
email: jay-ford@uiowa.edu, phone: 319-335-5555, fax: 319-335-2951
