The Long Slow Death of IPv4 is almost at the end. Maybe.
ARIN (American Registry of Internet Numbers) announced today that it has issued the final block of IPv4 addresses that was available as part of its free pool. The "free pool" is the term used by ARIN and IANA (Internet Assigned Numbers Authority) to describe the inventory of IPv4 address blocks freely available to be distributed.
The fact that the free pool of IPv4 is exhausted does not, however, mean that there are no more IPv4 addresses, but just that new free allocations from ARIN are in extremely short supply.
"ARIN will continue to process and approve requests for IPv4 address blocks," ARIN stated. "Those approved requests may be fulfilled via the Wait List for Unmet IPv4 Requests, or through the IPv4 Transfer Market. "
There are multiple vendors in the IPv4 transfer market, including IPv4 Market Group, which buys and sells IPv4 address space. Sandra Brown, president of the IPv4 Market Group, explained to Enterprise Networking Planet in an April video interview that pricing for IPv4 address space is in a constant state of flux.
Going a step further, ARIN itself is able to "reclaim" unused IPv4 address space from time to time. Reclaimed address space can sometimes simply be returned to ARIN after an organization realizes that previously allocated addresses are not needed.
"In the future, any IPv4 address space that ARIN receives from IANA, or recovers from revocations or returns from organizations, will be used to satisfy approved requests on the Waiting List for Unmet Requests," ARIN stated. "If we are able to fully satisfy all of the requests on the waiting list, any remaining IPv4 addresses would be placed into the ARIN free pool of IPv4 addresses to satisfy future requests."
The end of the free pool of IPv4 address space in ARIN comes four and a half years after IANA officially declared that its free pool of address space had been exhausted.
IPv4 provides for up to 4.3 billion addresses, while IPv6 has a 128-bit addressing scheme and support for 340 trillion, trillion, trillion (34 x 10 to the 38th power) addresses. Overall adoption of the IPv6 in the ARIN zone of North America has been relatively slow. With the ending of the free pool, that adoption pace may well pick up sooner, rather than later.
Sean Michael Kerner is a senior editor at Enterprise Networking Planet and InternetNews.com. Follow him on Twitter @TechJournalist.