[CentOS] IP6 Anyone?
Stephen Harris
lists at spuddy.org
Sun Feb 27 14:45:14 UTC 2011
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
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