On Mon, 25 Nov 2002, Steven M. Bellovin wrote: > You run into the birthday paradox here. In a space of 2^38 address > blocks, with 2^19 "allocations" there's a 50% chance of at least one > collision. Given how many home networks will be using this stuff, > we'll have far more than 2^19. > > But that's not the interesting question. The interesting question is > what the odds are of two users of the space "colliding", and that in > turn depends on the average connectivity. On that I have insufficient > data.
The requirement for birthday paradox to be valid is when those networks are totally interconnected; for that, the number is like 2^19. I fail to see valid scenarios where even 2^5 site-local networks would be interconnected. I'm still assuming the site-locals, are, well, site locals. So valid interconnections would be: 1) sites connecting (e.g. two physical locations of one organization) 2) site-local address info leaking though some ways outside of sites where there is site-local connectivity 1) is which seems to be critical, but I still fail to see a huge need for interconnection. 2) should not be relevant in the case that collisions are extremely rare, as the connections will fail anyway (the question is only _how_). -- 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] --------------------------------------------------------------------
