People sometimes ask me if I think IPv6 will take off in a big way. My answer is that there is no other contender to replace IPv4, and sooner or later we will have to move away from IPv4 as pressure on IPv4 addressing makes things more uncomfortable. One of the big areas of uncertainty has been when will IPv4 addresses actually be no longer available, for practical purposes.
Some smart people in the APNIC region have figured out that this uncertainty is bad for everyone, because it makes it hard to plan. They have written a proposal suggesting that once the pool of remaining IPv4 addresses hits some level (they suggest 30*/8), then we say “two years from now we will stop allocating IPv4 addresses, except in emergencies”.
(It is unlikely that 30*/8 can be consumed in two years, but clearly some thought is necessary to correctly set the level and the time scale.)
This seems like a very clever plan. It means we all get two years notice that there won’t addresses be available, and so we should start planning now, thus removing uncertainty. Everyone gets the same notice, so it is fair. Finally, we keep a little in reserve, so that we can patch things up if some globally important obstacle presents itself.
It’s not clear to me if this proposal makes the rush for the last few available IPv4 addresses better or worse, but it certainly seems to make people’s job easier when it comes to planning what is needed.