On Thu, 21 Nov 2002, Michel Py wrote: > > Christian Huitema wrote: > > we want to remove ambiguity, which is the root cause > > of many problems occuring when scoped addresses leak. > > If we want these addresses to be used, there are two things we need to > do: > > 1. Make these addresses globally unique, which is effectively removing > ambiguity. As of today, I don't see how we could achieve this without a > uniqueness database. [...]
One idea IMO is that we don't even want to be aim for total, provable, complete uniqueness. Looking at some requirements, I believe "unique enough" is good enough. Especially if we focus on the -real- case, non-globally routable addresses. FEC0::/10 has about 38 usable bits there. That's enough for "unique enough". No need for even that. Let's assume /16 - /40 -- 24 bits would be enough too. By birthday paradox, even in that case, collisions should only be probable if you communicate thousands of different sites simultaneously and there are referrals and third party interconnections. Take your name, address, phonenumber or whatever (it must be long enough, though), apply a hash function and BAM -- there you have "unique enough" site-id identifier. No need for any registrations etc. As long as the site-id identifier is created with a clear conscience, based on enough material (what you use is really irrelevant, but several options could be listed) so the hash function provides values random enough to be useful, you're done. If you want globally routable addresses, this is of course a non-starter. There, a geographical addressing, based on e.g. GPS readings like Tony has suggested, is probably the easiest. But I don't think we should be providing _globally routable_ addresses in the first place. They answer some other problems than the one that's an argument in the site-local discussion. -- Pekka Savola "Tell me of difficulties surmounted, Netcore Oy not those you stumble over and fall" Systems. Networks. Security. -- Robert Jordan: A Crown of Swords -------------------------------------------------------------------- IETF IPng Working Group Mailing List IPng Home Page: http://playground.sun.com/ipng FTP archive: ftp://playground.sun.com/pub/ipng Direct all administrative requests to [EMAIL PROTECTED] --------------------------------------------------------------------
