On Sun, Feb 27, 2011 at 01:44:17PM +0000, Always Learning wrote: > I was actually wrong. I can 'play' with not 2 but 4 groups of the IP6 > allocation. Golly, what can I do with 64 x 64 x 64 x 64 address That's an odd combination. "64" is 6 bits, which has nothing to do with an IPv6 group. Many IPv6 allocations to end users are a /64, which means you get something like aaaa:bbbb:cccc:dddd:****:****:****:**** to play with; the a->d are fixed, you get the rest on your own. That's actually 2^64 (or 65536*65536*65536*65536, or 18,446,744,073,709,551,616) addresses. IPv4 only has 2^32 addresses in total! I have 2 /64s via tunnelbroker.net (one for home, one for my linode) and a native /80 from Panix for my v-colo. Organisations may actually get /48 networks, just in case they're gonna run out. Actually it's if they want to subnet and route; a /64 is the best smallest subnet in many cases because of address autoconfiguration, so a /48 allows them to build 2^16=65536 subnets. > combinations? Hire then out? Have a different IP6 address for every > hour of the year? Put the IP4 address in the last 4 groups? > (2001::10.2.2.191) Well, you won't have 2001:0:0:0:0:0, but there are mechanisms for this actually :-) 2001::10.2.2.191 is a perfectly valid way of writing 2001::0a02:02bf and is designed to help with the transition. -- rgds Stephen