[arin-ppml] V6 address allocation policy

michael.dillon at bt.com michael.dillon at bt.com
Thu Jan 21 03:49:22 EST 2010

> Great.  So for my campus which is made up of 50 different 
> street addresses I can get 50 /48s...

Precisely. That's the way that the IPv6 designers intended it
to be. If one of those locations decides to build a lab which
does some kind of mobile device experimentation, and they need
10,000 /64 subnets, you have no problems because their /48 has
plenty to spare. 

One of the outcomes of IPv6 is that as far as possible, networks
will have more than enough address space so that they can expand
without renumbering. The /64 subnet will never run out of interface
addresses. For 99% of sites, their /48 will never run out of /64
blocks, and for 80% of LIRs/ISPs, their /32 will never run out of
/48 site assignments. And in the private residences, as long as they
remain private residences, that /56 will never run out of /64 
subnets even when they put in a mother-in-law suite.

--Michael Dillon

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