It could very well be worth making sure you’re IPv6 compatible… just in case The Switch happens sooner than later.
Yesterday, the Internet Assigned Numbers Authority (IANA, part of ICANN), allocated two blocks of 16.8 million IPv4 addresses to the RIPE NCC and another two blocks to ARIN. The RIPE NCC and ARIN are the Regional Internet Registries that give out IP addresses in greater Europe and North America, respectively. This brings the global pool of still available “/8” address blocks that IANA maintains from 11 down to 7.
via Global pool of IPv4 addresses set to run dry in weeks.
Iljitsch van Beijnum has written an excellent article on the upcoming doom that will be the IPv4 to v6 transition.
Legacy problems will be huge – there are home users running every ancient OS ever available out there.
There is no plan B. Despite the long list of the issues with IPv6 and its deployment, there are no alternatives. It took us the better part of two decades to get this far with IPv6, and there’s no way we can come up with, implement, and deploy an alternative before the lack of IPv4 addresses becomes a serious problem.
via There is no Plan B: why the IPv4-to-IPv6 transition will be ugly.