[CentOS] IP6 Anyone?

Sun Feb 27 14:45:14 UTC 2011
Stephen Harris <lists at spuddy.org>

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
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:: 

Well, you won't have 2001:0:0:0:0:0, but there are mechanisms for this
actually :-)

2001:: is a perfectly valid way of writing 2001::0a02:02bf
and is designed to help with the transition.