IPv6 Subnet tool

[Doug Barton]

Martin List-Petersen wrote:
> As for assigning only a /56 to end-users or by default, this is very
> sensible, even though us ISPs have been given a huge amount of IP space.
> But hell, when /8's were given out, there was no shortage of them
> either, was there ?

I have long advocated flexibility in allocations for this reason,
among others. One of the things I've never understood about the
"everyone gets a /48" idea is that different people have different
ideas of what the units of "everyone" are. (Even in this one thread if
you look carefully.)

The more important reason I believe in being conservative initially is
that if I'm wrong, it's easy to go the other direction. "We assigned
you a /56 initially to be on the safe side, but it's 10 years after
widespread IPv6 deployment now and we've tons of addresses after all,
so here is a /48, via con dios." OTOH, the initial IPv4 deployment has
taught us that once someone gets a block they hold onto it with an
iron fist, thus making it nearly impossible to move in the other
direction if it turns out that those of us who urged more conservative
policies were right all along.

Please note, it is not my intention to revisit this entire debate, I
fully realize that it's a hobby horse for a lot of people. :)

Doug