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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical RE: Policy Routing
Jon, Unless I am misunderstand how BGP (and routing at all) works something very seriously wrong with your suggestion. Your border router will advertise to a customer only best and active routes. You cannot advertise to BGP peer two routes to the same destination. So modifying AS_PATH will not work, because you will send to Customer X only best selected route from your border router. The only way to advertise suboptimal route would be to have it selected as 'best' on your border router. Of course, technically, you can advertise one thing (AS_PATH via NSP A) , and forward it to a different destination (NSP el'cheapo), but this is another story. Please correct me if I am wrong -- it is 1:40 am and I had a long day... Thanks, Przemek -----Original Message----- From: [email protected] [mailto:[email protected]]On Behalf Of [email protected] Sent: Sunday, August 26, 2001 1:27 AM To: John Fraizer Cc: Jeff Cates; [email protected] Subject: Re: Policy Routing On Sun, 26 Aug 2001, John Fraizer wrote: > Rereading your post, one would believe that since "Company X" is a BGP > customer of yours, you're going to be sending them a full view. Unless > there is a knob that I'm not familiar with, that means that you're going > to be sending them the _BEST_ routes that you see in your core and not > just those from "NSP A" to which you are proposing to policy-route all of > "Customer X's" traffic. If this is indeed the case, I would think that > policy-routing the customers traffic destined for "prefix Y" via a > path other than the path listed in the NLRI you're sending "Customer X" on > their BGP feed is outright fraud. Suppose you apply an output route-map on their BGP session that prepends the heck out of paths where peer-A isn't your next as-hop? That way, you're giving them full routes and making it clear via BGP that if they have another path via another provider for non peer-A routes, the other will be better. -- ---------------------------------------------------------------------- Jon Lewis *[email protected]*| I route System Administrator | therefore you are Atlantic Net | _________ http://www.lewis.org/~jlewis/pgp for PGP public key_________
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