Re: [isp-bgp] filtering pratice

[Daniel Schild <sch-ispbgp@...>]

On Tue, May 24, 2005 at 05:48:34PM -0400, Darrell Hyde wrote:
> Its always best to be proactive in route filtering for both routes you
> receive and routes you announce. I've always found it sufficient to use
> prefix-lists to filter routes that I'm announcing, and prefix-lists in
> conjunction with filter-lists (as-path access-lists) to control what I
> accept from my peers.
> 
> This of course assumes that you're peering with a fairly small network
> that doesn't have any end users with their own ASN's. If that's not the
> case, and you're peering with more of an ISP style network with end-user
> ASN's, then its common for them to tag their routes and their customers'
> routes with a specific BGP community that you can selectively filter on
> in your route-maps.
> 
> - Darrell
> 

hi,

when i discussed this "issue" with a friend of mine, and i suggested
that we should filter on their community, he told me that communitys are
_only_ there for engineering, so we can change how our peers are
treating our routes. I understand how that works, that we can set
different communities then our peer will treat us different, that's not
the problem. So, if i understand you right, it's a common/good/whatever
thing to filter on their communities?


i realised that i wrote quite strange in my first post.. when i'm
reading it now, i don't understand it as it was meant to be ;).
The isp we're going to peer with is quite large and have a lot of
customer asn's, so we can't do any strict prefix-filtering (but i will
consider doing loose filtering, as somebody (forgot his name) did post
about).

so, right now i'm about to filter on
- community
- as-path (their asn + 1)
( loose prefix )


thanks for everybody's answers.


and about our outgoing routes, i'm strictly filtering on our only prefix
and our only as, so i hope that'll be sufficient (we don't have any
customer asn's).


kind regards,
daniel





To unsubscribe via postal mail, please contact us at:
Jupitermedia Corp.
Attn: Discussion List Management
475 Park Avenue South
New York, NY 10016

Please include the email address which you have been contacted with.

Copyright 2005 Jupitermedia Corporation All Rights Reserved.