Kre and Philip, > I find it almost impossible to work out where /80 comes from (unless > you mean to find a need to do so, in which case, then yes, I'd find > that pretty difficult too, though I prefer more often to have > constant 0 bits in higher order positions than lower ones, so I'd > tend to make the mask longer, and put 0's in the subnet section > rather than shorter with 0's in the host part - but that's just > aesthetics). But if there's something supposedly magic about the last > 48 bits (48 now is 100% irrelevant to autoconf, so it cannot be > that) it has escaped me.
What I had in mind was that if someone felt like re-inventing the wheel and create a new autoconf, it would be extremely difficult not to use the 48-bit MAC address (nobody would buy having ARP for IPv6), therefore going beyong /80 would be very difficult. > For giving advice to the population at large, I'd probably suggest using > /64 for almost all nets, to lower the chances of running into limits in > the technology that shouldn't be there (but bugs exist everywhere). Concur. > Philip Homburg wrote: > What happens if an organization has a modem bank for dail-in? Do you > hand out /64s or something larger? Suppose that you want to give each > 'modem user' a fixed prefix, how soon do you run out of prefixes? Modem users will be more than happy with a /64, because they do not need to subnet. If one wants to share the modem connection for their home network, that home network is a single subnet and will do fine with a /64. Broadband home connections (cable/dsl) would do ok with a /64, too, for the same reason. Why would someone want a /68 (or whatever) for the living room, a /68 for the john, a /68 for the kitchen, a /68 for the garage? Michel. -------------------------------------------------------------------- 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] --------------------------------------------------------------------
