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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: solving problems instead of beating heads on walls
On Sat, 27 Jul 2002, Brad Knowles wrote: > > At 10:56 AM -0400 2002/07/27, Andy Dills wrote: > If you buy bandwidth from two different providers at two > different locations, this would seem to me to be a good way to > provide backup in case on provider or one location goes > Tango-Uniform, and you could always backhaul the bandwidth for the > site/provider that is down. > > So, what am I missing? The issue is how you want to influence inbound traffic. If you have the scenario you just described but want to keep as much traffic off your own intercity links as possible the only solution is to announce more specific networks that are heard globally. If you're ok with transporting a lot of intercity traffic between your locations, and just announce the same prefix everywhere, none of this applies and you've done your part to not pollute the DFZ. If you connect to the same transit(s) in both cities you can announce more specific networks with no-export set, keep most of your external traffic off your own network, and not cause the entire world to know about your more specific advertisements. Responsible yet lacking some redundancy: connect to the same single provider in both locations and announce more specific networks w/ no-export. Irresponsible yet gaining redundancy: connect to a different provider in each region and announce more specifics. no-export not an option, longer prefixes heard globally. Responsible and overall best: connect to the same 2+ providers in both locations and announce more specifics locally in each region/city/whatever with no-export. Your two or more transit providers have the more specific networks to bring the traffic to you across the last leg, but the rest of the world doesn't know/care about/have to deal with it. draft-ietf-ptomaine-bgp-redistribution-00.txt has some really good knobs to twist in order to engineer your traffic without making the rest of the world suffer. If/when it goes RFC getting people to actually make use of it will be painful, but atleast the horse is being taken to water. - Paul
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