The Internet is quickly running out of space. To be exact, it’s running out of the IP addresses that define where systems and devices are on the network, which guide how the data packets get from one place to another.

The more than 4 billion addresses that the current IPv4 allows — a seemingly unimaginable number when TCP/IP was deployed in the early 1980s — now look hopelessly outmatched in a world that already counts one-sixth of the population as users and envisions phones, refrigerators and even the clothes on our backs as potential nodes on the network.

Workarounds — such as Network Address Translation, which allows a single server to act as the address for all the nodes on a local network— have helped extend the life of IPv4, but they introduce other complications. The real answer is to increase the number of addresses.

Who has to make the move to IPv6, and when?
Enter IPv6. This next-generation version of IP uses a 128-bit address space, just four times more than IPv4, but that boosts the number of available unique addresses to 3.4 x 1038. That’s enough so that each person on Earth can have 50 octillion (5 x 1028).

In addition, IPv6 offers more significant benefits than its predecessor in terms of network management, security and performance.

The question for government users is how to make the move from IPv4 to IPv6.

The Office of Management and Budget simplified those issues when it issued a directive in 2005 that required all government agencies to move their backbone networks to IPv6 by June 2008 — meaning they should operate either IPv4/IPv6 dual-stack network cores or operate them only in IPv6 mode — and that agency networks must be able to interface with them.

Agencies have to meet certain milestones before June 2008. By Feb. 28, most agencies had to give OMB details of their transition plans. By June 30, they have to complete an inventory of the IP-based applications and devices on their networks and an analysis of how they expect the move to IPv6 will affect them.

As they near the 2008 deadline, agencies will include progress reports as part of their regular, annual enterprise architecture submissions to OMB.

What will the transition cost?
That could be one of the hardest things to measure, and some advise not even trying. “I think that’s a trap, because no one really knows,” said Frank Cuccias, program manager for Lockheed Martin’s IPv6 Transition Support Office. “You need to look several years ahead, account for the people who have to be trained, how much you’ll spend on lab and testing resources and so on.”