[arin-ppml] "Millions of Internet Addresses AreLying Idle"(slashdot)

Paul Vixie vixie at isc.org
Tue Oct 21 15:33:45 EDT 2008

michael.dillon at bt.com writes:

> I agree that a reclamation policy aimed at staving off IPv4 exhaustion is
> a waste of our time. However, a reclamation policy aimed at the new
> reality of an IPv6 Internet is worthwhile. This will be a world where
> IPv4 infrastructure is steadily, if slowly, being phased out and
> shutdown. At that time, there will still be many non-Internet users of
> IPv4 addresses, and it is entirely possible that they will be used for
> special purposes for another 20 years or longer. In that case our
> responsibility as stewards is to make sure that the bulk of the unneeded
> IPv4 address space is recovered so that it is available for future use.

can you explain why someone would stop using IPv4 if it still reached the
entire set of endpoints they wanted to exchange traffic with?  or failing
that can you explain why someone would switch to IPv6-only if it would
limit the set of endpoints they could exchange traffic with?

right now there's V4-only and dual-stack but there is no V6-only since it
offers inadequate connectivity.  we can expect a lot more dual-stack as we
approach and then pass runout day.  some day most of us expect the cost of
V6-only (which will be some moderate loss of connectivity) to be lower than
the cost of continuing with (which will be double/triple NAT, high prices
for leasing IPv4 RTU [perhaps as bundled with carriage], and router cost
and heat for the pea-sized gravel that the IPv4 routing table will become).

but noone i know expects that there will ever be a time when one set of
users is releasing IPv4 because they're happy with IPv6-only and IPv4-NAT,
while another set of users still needs to grow their IPv4.  unless it's
you, that is.  i'd like to hear more about this world view.
Paul Vixie

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