RE: [isp-bgp] filtering pratice

["Darrell Hyde" <DHyde@...>]

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

> -----Original Message-----
> From: Daniel Schild [mailto:sch-ispbgp@...] 
> Sent: Tuesday, May 24, 2005 3:50 PM
> To: isp-bgp@isp-bgp.com
> Subject: [isp-bgp] filtering pratice
> 
> Hi,
> 
> I'm just about to peer with another isp, and now i'm wondering what's
> the best filtering pratice when it comes to peering. Do i just allow
> everything from the other isp, hoping that they don't mess 
> up? the most
> important thing is to have some kind of control of what 
> routes they give
> us, since we don't want to end up with them giving us a full table or
> something like that.
> 
> The first thing i can think of is filtering on as-path, but i 
> know they
> have other customers with their own asns. Of course i could always
> filter on the as + 1, but i just want to hear about what the 
> most common
> pratice in this case is. Also, they have a couple of ip 
> blocks, so we don't
> want to filter on their blocks (if we do, we also have to know if
> anything changes). Also, i don't know if any of their 
> customers as's have
> customers with their own asns, and so on (probably not very likely).
> 
> So, how much do you people filter from your peers?
> 
> 
> best 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.
> 





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.