IPv4 Address Exhaustion Not Instant Cause for Concern with IPv6 in Wings

By Fahmida Y. Rashid  |  Posted 2011-02-01

IPv4 Address Exhaustion Not Instant Cause for Concern with IPv6 in Wings

The last IP address blocks in the IPv4 namespace will be automatically assigned to the organizations overseeing the net address assignments three months earlier than expected.

The Asia Pacific Network Information Center (APNIC), the organization that oversees net addresses in the Asia-Pacific region, requested and received two blocks of addresses from the Internet Assigned Numbers Authority (IANA) on Feb. 1. The assignment triggered an ICANN rule (Internet Corporation for Assigned Names and Numbers ), which states that when only five blocks of addresses remain in the pool, they will be parceled out evenly between the five regional agencies.

The rule was expected to kick in around May 26, according to the IPv4 Address Report program back in September. IPv4 Address Report is an online script that calculates how many addresses are left in the namespace. As of Feb. 1, the program calculated that only 1 percent of all possible IPv4 addresses are left unassigned.

Once the five remaining blocks are allocated, the regional registries will continue assigning addresses in these blocks, each containing 16 million IP addresses, until the supply runs out. South American and African registries are expected to last longer since there's comparatively less demand in those regions at this time. The entire address space is expected to be more or less exhausted by Sept. 24, according to the IPv4 Address Report.

Major Internet service providers and infrastructure companies have been preparing for IP-address exhaustion for years and there are transition plans in place, according to networking experts. "It's easy to create alarm with forecasts of the end of Internet address [space], but while there is a lot of smoke, there is no actual fire," said Alain Durand, director of software engineering at Juniper Networks.

APNIC will continue "normal allocations" for another three to six months, and then restrict assignments so that enough addresses are available during the transition to IPv6, the organization said. Under this policy, the organization expects to keep assigning addresses for another five years, APNIC said.

"The future growth and innovation of the Internet is now reliant on deployment of IPv6," said Axel Pawlik, managing director of RIPE NCC, the regional Internet registry for Europe and Middle East.

The current IPv4 naming scheme was developed in the 1970s and had capacity for 4.3 billion addresses, which were grouped into 255 blocks of 16 million addresses each. The replacement scheme, IPv6, has a staggeringly large number of addresses: more than 340 undecillion (for the curious, that's 340,282,366,920,938,463,463,374,607,431,768,211,456), grouped into blocks of 18 quintillion addresses.

Major Telecoms Starting Migration to IPv6


Arbor Networks surveyed IPv6 adoption in the summer and found that less than a tenth of a percent of all traffic used IPv6, "almost below the threshold of what we could measure," according to Craig Labovitz, the chief scientist at Arbor Networks.

While the infrastructure is in place for IPv4 systems and IPv6 systems to run in parallel, widespread adoption of IPv6 has been very slow because the two systems are not compatible and there was no economic incentive for companies to do so. "The two protocols can coexist, but they can't intercommunicate," Nigel Titley, chairman of RIPE NCC, told eWeekEurope. 

Users on systems with IPv6 addresses couldn't access sites and services with IPv4 addresses. "Gradually, as IPv6 usage ramps up, IPv4 usage will ramp down. And eventually it will get to a point where we envisage retiring IPv4 altogether."

While the transition from IPv4 to IPv6 many be a little bumpy for larger organizations, it shouldn't be calamitous at all for most companies. Modern computers are generally IPv6 compliant, but businesses may need to upgrade their routers and switches.

"It's a gold mine because everybody eventually has to upgrade" to equipment that is compatible with IPv6," Joel Conover, a Cisco senior marketing manager, told the Wall Street Journal.

Many large sites, such as Google, have already rolled out an IPv6 site for customers already on that system. Google, Facebook and Yahoo are among some of the larger companies planning a one-day test run of IPv6 addresses as part of World IPv6 Day, on June 8, to encourage the transition to the new namespace.

Major telecommunication companies have been upgrading their infrastructure over the past few years in anticipation of the transition. Comcast has begun assigning IPv6 addresses to its cable modem customers in a "native dual stack" configuration, wrote John Brzozowski, the cable company's chief architect for IPv6, on the corporate blog on Jan.31. Under this configuration, customers have both IPv4 and IPv6 addresses and can access content and services over both systems. Comcast's first 25 IPv6-enabled customers went live Jan. 11 in the Littleton, Colo. area, according to the post.

TimeWarner Cable has already signed up commercial customers on IPv6 and plans to begin residential IPv6 trials in the spring. TimeWarner Cable is also expected to adopt a dual-stack approach similar to that of Comcast. "Time Warner Cable has long been preparing for the eventual end of IPv4 address availability," said chief technology officer Mike LaJoie.

Domain infrastructure company VeriSign will also provide business services to assist companies with the transition during the year, the company said during its earnings call.

"The sky is not falling, but rather there is a real opportunity to do so much more with how the Internet connects everyone to everything," said Durand.

Rocket Fuel