Internet Companies Poised To Switch On IPv6 For Good


At 8 p.m. Eastern on Tuesday, June 5, the Internet will change forever -- or so the organizers of the World IPv6 Launch event hope.

Comcast, Time Warner Cable, AT&T and Verizon Wireless are among the Internet service providers that have committed to enabling the next-generation IPv6 protocol for at least 1% of their users for World IPv6 Launch, set to begin at midnight Coordinated Universal Time (UTC) on June 6.

World IPv6 Launch logo

In addition, more than 2,000 websites -- including Google, Facebook, Microsoft Bing, Yahoo, AOL and Netflix -- pledged to turn on IPv6 permanently for their main websites with World IPv6 Launch, alongside the existing IPv4. (In fact, Facebook already has enabled IPv6 permanently.)

"World IPv6 Launch Day is a lot larger than people understand," said John Curran, president and CEO of the American Registry for Internet Numbers, the body that assigns IP address space to ISPs and other organizations in North America and parts of the Caribbean.

The shift to IPv6 "is the single largest upgrade in the history of the Internet," Curran continued. "It's not a small decision for the major content providers to turn on IPv6 and leave it on... The good news is that done properly, Internet users globally will not notice any significant difference in their daily lives."

The move to IPv6 is becoming urgent for ISPs and other Internet companies as the pool of 4.3 billion available addresses in the current IPv4 nears exhaustion.

Comcast, for one, said that as of May 24 it has launched and enabled IPv6 in over one-third of its broadband network, in areas that are served by Arris cable modem termination systems. The MSO is deploying IPv6 in a "dual-stack" implementation, providing customers native access to both IPv4 and IPv6 sources, which it began on its live commercial networks last fall.

IPv6 is available to approximately 6 million Comcast subscribers, but just roughly 5% of those are actually connecting via the protocol natively on their home-networking equipment and PCs, said John Brzozowski, Comcast distinguished engineer and chief architect for IPv6.

For World IPv6 Launch, Comcast is setting up a war room "to assess the success of the event," Brzozowski said, adding, "We expect this to be incident-free." A key question will be how much traffic ends up being native IPv6, he said: "If that IPv6 take rate is too low we have a lot of work to do."

World IPv6 Launch, organized by the not-for-profit Internet Society, comes one year after the 24-hour World IPv6 Day test on June 6, 2011. In addition to the participating ISPs and website operators, home networking equipment manufacturers including Cisco Systems and D-Link have said they will enable IPv6 by default across their home router products by June 6.

"The support of IPv6 from these thousands of organizations delivers a critical message to the world: IPv6 is not just a 'nice to have'; it is ready for business today and will very soon be a 'must have,'" Leslie Daigle, the Internet Society's chief Internet technology officer, said in a statement.

IPv4 and IPv6 are not compatible. At first, ISPs like Comcast are rolling out dual-stack support so customers can access content on both IPv4- and IPv6-hosted sites. But longer term, users with IPv6-only end devices will not be able access legacy IPv4 services without some intermediate translation.

Only 25% of North American ISPs have deployed IPv6 to date but all plan to do so by the end of 2012, according to a survey of 67 ISPs worldwide by Nominum, a provider of DNS-based applications and solutions for service providers. The ISPs in the survey, released Tuesday, have a combined reach of 110 million households.

Comcast expects to complete IPv6 deployment on all its Arris CMTSs over the summer, and will then turn to its Cisco Systems CMTSs. Currently, the operator's Xfinity and XfinityTV websites are dual-stack-enabled and on Tuesday Comcast turned on pilot tests for both inbound and outbound email servers.

Brzozowski said Comcast will be able to operate in dual-stack mode "for a bit," without specifying a time horizon until IPv4 addresses would run out. "We are really laser-focused on enabling IPv6, and once we have network-wide coverage then we can have a conversation about what comes next," he said. The MSO is not ruling out network address translation, but "our plan is to never have to use it."

More info on World IPv6 Launch is available at