|
Thread Index [isp-bgp] Example
Hi Sawarkar, And how i use load sharing in inbound traffic? Regards, Marcelo Moulin S ubject: Re: isp-bgp digest: December 07, 2004 From: FeatureBug <featurebug@...> Date: Wed, 8 Dec 2004 23:32:46 -0800 (PST) X-Message-Number: 2 Hello All We must be careful to distinguish between load-sharing and load-balancing. Even I blurred the distinction of what I was talking about in my last post. Load-balancing (with mulipath) is not be possible when multihomed to two AS'es but load sharing is - for outbound traffic. But here's a possible solution: When multi-homed to two AS'es, 1. Arrange to receive full routing updates from both. 2. Then weed out ip prefixes that belong to the specific AS'es only. You'll need a pencil and paper and the internet for this. 3. Take the balance list of prefixes that is left, and divide it into two sets that are roughly equal. For prefixes common to both i.e advertised by both, use a route-map for each BGP peer in the neighbor statements and assign a weight (assuming cisco implementation) to one set of incoming routes with corresponding access-lists - so that matching routes prefer the path thru the corresponding BGP neighbor, and another route-map matching the other set of incoming routes (access-list deny {1st set} permit {2nd set}), assingning a weight to matching routes preferring the second ISP. You will have to update the access-lists manually and regularly .... Your comments? Referring to Ejay's post, AS prepending is only possible on the advertising router, let me clarify. And getting your ISP to modify routes for you will cost you in the best case - in which case you need not assign weights on your side. Worst case is that most likely your request will be be ignored or refused... Rgrds Rahul Sawarkar 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.
Thread Index |
|
