On Fri, 2005-10-14 at 10:57 -0400, Joe Abley wrote: <SNIP> > Are you suggesting that something else is required for ISPs above and > beyond announcing PI space with BGP, or that shim6 (once baked and > real) would present a threat to ISPs?
There is one situation which is not really covered here, one can of course announce multiple de-aggregates, but, these will be filtered. As such announcing them will only hurt one a lot, as the 'transits' that do carry them are mostly of bad quality. eg take the following situation: Big ISP, or a large corporate network, spread around the world. >200 customers and so, thus they can easily get a IPv6 prefix from their favourite RIR. Thus they get, say a /32. Now this ISP has a large webfarm in the US. They have a very small one in say, Taiwan. In IPv4, this would mean: chunk up your PA and simply announce them in /20's or whatever is comfortable for you. In IPv6 though, one is not supposed to announce chunks out of the /32, also when you do, as mentioned above, one gets bad routing. Anyway, you don't want your farm in Taiwan to attract all the local (complete asia?) traffic, which you have to ship over that same small link or your internal network in taiwan to the US again, while in IPv4 others would be doing that. In this case, which is basically "traffic engineering for endsites with a global prefix", one runs into the shim6 thing again.... For instance UUNET 'solved' this in a different way, they simply requested a 10 or so separate /32's. See GRH for the list. These chunks are still /32's thus only <n> of these /32's can exist in the global routing table. It would still be 'nicer' if they only had to use one prefix... Greets, Jeroen
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