IPv4: The final farewell begins

Last blocks of Internet addresses likely to be allocated this week, putting IPv6 on deck

This article was updated at 3:45 p.m. Feb. 1.

The Internet Assigned Numbers Authority on Monday allocated two blocks of IPv4 Internet addresses to the Regional Internet Registry for the Asia-Pacific region, triggering the final distribution of IPv4 addresses, expected as early as this week.

The final distribution of the current generation of IP addresses is a major milestone in the Internet’s brief history and means that future Internet growth will be in the next-generation IPv6 address space.

“There is really nothing new here,” said Qing Li, chief scientist for Blue Coat Systems, an application delivery company. The Internet community has been warned for years that the current generation of addresses eventually would run out, requiring a transition to IPv6.

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Current IPv4 addresses and the Internet infrastructure supporting them will not go away, and new IPv4 addresses will continue to be assigned from previous allocations still in the hands of the regional registries, and from carriers, service providers and other organizations that still have allocations of the addresses. The U.S. government, which created the Internet and claimed its address space early, is believed to have significant reserves of unused IPv4 addresses.

But as the current supply of IPv4 addresses runs through the system, new allocations increasingly will be made from the next version of the Internet Protocols, IPv6, which was developed with a much larger address space.

Since December, less than 3 percent of the original IPv4 address space remained available at IANA, with just seven /8 blocks (pronounced “slash-eight”) containing about 16 million addresses each remaining to be allocated. IANA allocates the addresses to the five Regional Internet Registries, AfriNIC, which covers Africa; APNIC, the Asia and Pacific region; ARIN, North America and parts of the Caribbean; LACNIC, Latin America and parts of the Caribbean; and RIPE NCC, Europe, the Middle East and parts of Central Asia. IANA had announced that when only five /8 blocks of IPv4 remained they would be distributed one each to the regional registries.

Two of the blocks, the 106/8 and 039/8, were allocated to APNIC on Monday.

“Please be aware, this will be the final allocation made by IANA under the current framework and will trigger the final distribution of five /8 blocks, one to each RIR under the agreed ‘Global policy for the allocation of the remaining IPv4 address space’,” IANA said Tuesday in a statement posted online.

Just how soon the new addresses will begin working their way into the Internet and generating traffic is difficult to say. IPv6 addresses have been available for a decade, but according to some surveys, less than 1 percent of Web sites are enabled to handle IPv6 traffic and the amount of IPv6 traffic on the Internet is negligible.

“After the final allocations, each RIR will continue to make allocations according to their own established policies,” IANA said in its statement.

The APNIC policy calls for normal allocations of IPv4 addresses to continue for a further three to six months. After that, the registry will continue to make small allocations from the last /8 block of IPv4 addresses to ensure that the address space is available for IPv6 transition. “It is expected that these allocations will continue for at least another five years.”

But IPv6 addresses are expected to begin coming online in large numbers well before that. Because the two protocols are not interoperable, both versions will have to be enabled on the existing Internet infrastructure to allow all users to have access to online resources. In September, the Office of Management and Budget directed civilian agencies to upgrade public-facing servers and services to handle IPv6 traffic by the end of fiscal 2012. Internal IP applications and systems must be upgraded by the end of fiscal 2014.

In the short run, there are a number of transition steps that carriers and content providers will be using, said Alain Durand, director of software engineering at Juniper Networks. Each regional registry has policies to allow the transfer of already allocated but unused IPv4 addresses to another party, which could extend the existing pool of addresses, he said. Enterprises also can make more efficient use of their existing IPv4 address space, largely through the use of Network Address Translation, which allows the use of private addressing behind a NAT device.

“NAT is well-known today,” Durand said. “It is simply going to be leveraged much more.”

Eventually, resources will have to be enabled to handle both types of traffic, which will mean managing and securing networks with both types of traffic for the foreseeable future.

“The complexity eventually will push networks toward using just IPv6,” Li said.

A press conference has been scheduled for Thursday by the Number Resource Organization, the Internet Corporation for Assigned Names and Numbers, the Internet Society and the Internet Architecture Board, at which they will make “a significant announcement and to discuss the global transition to the next generation of Internet addresses.”

“Much has been written in the international media over the last few weeks about the dwindling pool of Internet addresses using the original Internet protocol, called IPv4, and this topic will be addressed at the event,” according to the announcement of the press conference made by the regional registries.

The announcement is expected to be of the final distribution of the remaining five blocks to the registries.


About the Author

William Jackson is a Maryland-based freelance writer.


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