The Great Reclamation
It's easy to forget in the day-to-day administration and management of the Internet's names and numbers that the network is still a young invention with a living history—one that is still be written as we speak. A recent effort by IANA to reclaim a part of that old network for new users helped put that history into context.
After several months' spent locating and contacting 29 organizations and obtaining their permission, IANA has managed to free up one up of the 256 blocks of IP addresses that make up the current Internet.
The "slash-8" was number 14 if you view IP address as a list of 256 items and was assigned to the Public Data Network. The space was specifically set aside in June 1991 to connect IPv4 networks to the ITU's X.25 networks.
In that sense, block 14.0.0.0/8 is a piece of history. The X.25 protocol was one of the first efforts to use the new packet-switching technology to produce a more reliable, digital network. It preceded the OSI model that was pushed heavily by the ITU but which was finally set aside in favor of the TCP/IP model that the Internet as we now know it runs on.
Detective work
But despite X.25 still being in use in a few countries, its IP address block is no longer needed, and so IANA ran through all the recipients of IP addresses in that block since 1991, and asked if they would agree to return their allocation. In some cases, the contact information was out-of-date; in others, there was no contact information. But after some detective work by the technical community, all those in charge of the 984 addresses in use were tracked down. At the end of August one, final registrant was researching the status of one last address.
In the first seven months of 2007, IANA has allocated nine slash-8s to the regional Internet registries, who then allocate them to organizations and businesses in their regions. Block 14 and its 16 million IPv4 addresses will be made available in the next few months, leaving just 47 blocks in the free pool of unallocated addresses. Or, put another way, with the Internet's growth as it is, the Public Data Network will buy roughly one-month’s worth of expansion time. The reclaim is unlikely to be repeated. We estimate it took six minutes per address. Fine when less than 1,000 exist in a block of 16 million, but a whole other world when the addresses have entered mainstream Internet use.
The future’s…big
The solution to the diminishing pool of IPv4 addresses is, of course, the step up to IPv6 networks. Barely 0.1 percent of the IPv6 address space has been allocated so far. And of that, only a tiny fraction is in use. How big is IPv6? If you could fit all IPv4 addresses into an iPod, it would take something the size of the Earth to contain IPv6. We're unlikely to need to go through a similar reclaiming exercise with IPv6 any time soon.
*Source: ICANN Monthly Magazine Sept. 10 email newsletter.