Slow but steady increase in IPv6 adoption reported

Network World - ANAHEIM – The Internet industry is seeing evidence that more consumers, corporations and Web sites are deploying IPv6, the long-anticipated upgrade to the Internet's main communications protocol, which is known as IPv4. But IPv6 remains a fraction of Internet traffic, and it's nowhere near where it should be given the rapid depletion of IPv4 addresses.

Invisible IPv6 traffic poses serious network threat

Comcast, Netflix and APNIC were among the Internet companies and organizations that provided new statistics about IPv6 deployment at an Internet Society panel held here on Tuesday.

Standardized more than a decade ago, IPv6 is just starting to gain momentum in the United States.

IPv6 is needed because the current version of the Internet Protocol – known as IPv4 – is running out of address space. IPv4 uses 32-bit addresses and can support 4.3 billion devices connected directly to the Internet. IPv6, on the other hand, uses 128-bit addresses and supports a virtually unlimited number of devices.

Experts predict that the remaining IPv4 addresses will be distributed in 2012. In January, the Regional Internet Registries announced that fewer than 10% of IPv4 addresses remain unallocated.

When IPv4 addresses run out, carriers and enterprises must support IPv6 in order to add new customers or devices to their networks. Otherwise, they will need complex and expensive layers of network address translation (NAT) to share scarce IPv4 addresses among multiple users and devices.

Geoff Huston, chief scientist at APNIC and an expert on Internet infrastructure issues, says IPv6 now represents 1% of all Internet traffic.

"The good news is that from 2008 to 2010, in terms of routing IPv6, we were growing faster than we thought," Huston said, pointing out that the number of IPv6 entries in the core routing tables grew from 1,000 to 3,000 in that timeframe. However, the number of IPv4 routing table entries now tops 300,000.

Similarly, Huston said the number of Internet hosts that support IPv6 has reached 1%. While that sounds tiny, Arbor Networks estimated in August 2008 that IPv6 represented only .002% of Internet traffic.

"The relative use of IPv6 has increased over the last four years to hit 1% of traffic," Huston said. He added that one cause for optimism is that "the folks in the transit ISP industry show that they get IPv6."

Comcast, which was the first ISP in the United States to announce an IPv6 trial, said it was surprised by the number of people who signed up to participate in the trial, which begins in April.

"We had 5,500 volunteers sign up in a matter of days," said Jason Livingood, executive director of Internet systems engineering at Comcast. "Not only did we get more volunteers than we expected, but we had people switching ISPs to participate in this trial. We also saw a lot of interest from our corporate customers, particularly for our fiber-based commercial service that is IPv6 ready."