|
Thread Index Re: [isp-bgp] managing BGP w/ a colo company
On Tue, Mar 01, 2005 at 12:38:11PM -0600, Pete Templin wrote:
> Bob Hrbek wrote:
> >We receive our bandwidth from a colocation company that has peering w/
> >Sprint, Qwest, Global Crossing and Level3. Recently the Level3 routes
> >started inducing some fairly significant latency. We announce our
> >networks
> >to the colo company which then announces them to their upstreams. Is there
> >anyway I can manipulate my BGP announcements so my inbound/outbound traffic
> >prefers a provider other than Level3? Can I just add L3's AS to my
> >announcement a few times? :)
>
> No. If you add L3's AS to your announcement, L3 will reject your
> announcement ("it's got a loop in the AS path!") AND the other networks
> may send your traffic to L3.
L3 will reject his AS_PATH, thereby hear it from another source, i.e.
his colo provider's another upstream, e.g. Qwest, GBLX.
Prepending your upstream AS or intermmediate AS in your AS_PATH creates
a very tasteless, confusing issue, but not necessarily create block in
traffic flow as long as done properly. I think I remember a couple big
networks who did this once in the past during their peering war vendetta.
e.g. Blah_ISP peers with Joe_ISP and John_ISP, and Blah_ISP buys transit
from Carrier1. Blah_ISP finds Joe_ISP not "big enough" to its likings, and
also finds out that Joe_ISP is a customer of John_ISP, another peer.
Blah_ISP depeers Joe_ISP and Joe_ISP prefixes are now heard from another
peer, aka John_ISP. Joe_ISP gets pissed off and prepends Blah_ISP's ASN
in the AS_PATH toward John_ISP.
Blah_ISP rejects AS_PATH from John_ISP due to path loop, and selects
path via Carrier1 transit upstream, and ends up with additional 1.2Gbps
showing up on their transit bill :)
-J
--
James Jun TowardEX Technologies, Inc.
Technical Lead Boston IPv4/IPv6 Web Hosting, Colocation and
james@... Network design/consulting & configuration services
cell: 1(978)-394-2867 web: http://www.towardex.com , noc: www.twdx.net
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.
Thread Index |
|
