World IPv6 Day - The Internet Protocol Journal, Volume 14, No.1

Phil Roberts, ISOC

On June 8, 2011, websites including Google, Facebook, Yahoo!, and Bing will make their main webpages reachable over IPv6 for a 24-hour period from 00:00 to 23:59 Coordinated Universal Time (UTC). This activity, World IPv6 Day, a "test flight" of IPv6, is motivating organizations across the Internet industry to prepare their services for IPv6, the next generation of the Internet Protocol. Internet Service Providers, hardware makers, operation system and application vendors, and other websites are indeed working to make this activity of testing IPv6 on an Internet scale successful.

The Internet is a never-ending exercise in collaboration. Making a successful transition to IPv6 is one of the major challenges facing the Internet today. Although IPv6 is used extensively in many large networks today, the World IPv6 Day activity is acting as a focal point to bring together all parts of the Internet industry to accelerate deployment of IPv6 in all parts of the Internet.

For some time the deployment of IPv6 has faced a "chicken-and-egg problem." Website owners have been reluctant to deploy IPv6 because there were not many end users to view their webpages over IPv6. Network operators have been hesitant to deploy IPv6 for many end users because there were few places for those users to view content over IPv6. That the most popular websites in the world according to Alexa rankings are deploying IPv6 on their main webpages is a clear indication that the Internet industry is moving beyond this long-standing impasse. Although June 8 is a 24-hour test, it is clear that this is a move toward regular operation of IPv6, and network operators can confidently roll out IPv6 to end users knowing that the Internet industry is making a concerted effort to make IPv6 an operational reality.

Today, IPv6 connectivity concerns provide another disincentive for a major website to enable IPv6 for regular operation. Badly configured or poorly behaving implementations may prevent end users from reaching a major website that enables IPv6 on its main page. It is currently estimated that this problem will affect only a minor percentage of end users—at the time of the announcement of World IPv6 Day, the estimate was that only 0.05 percent of end users would experience difficulties.

Although this percentage is small, it is potentially a very large number of end users for a website that has visitors numbering in the tens of millions (or more). It is simply impossible from a business point of view for a website of this magnitude to deploy IPv6 alone when this many users could be affected. The users who would not be able to get to that website will simply go to another website in search of similar services.

However, because several such websites have agreed to do this testing at the same time, and for the same duration, individual end users who experience disruption of their connectivity by IPv6 may be able to determine that the problem they are experiencing is indeed not a problem with a set of major websites but may, in fact, be a problem in their own host or network, and will provide an incentive for them to take steps to determine the source of the problem and repair it.

Website owners, network operators, and hardware and software vendors are collaborating to minimize these effects leading up to World IPv6 Day. All of these organizations are working to provide tools to detect these problems and offer suggested fixes in advance of June 8. The test site allows end users today to test their connectivity and determine whether their connectivity to websites will be affected when those websites enable IPv6.

Some websites have already performed a similar 24-hour test. Last year, the German online news site Heise ( conducted a similar experiment. The site enabled IPv6 on its main page for 24 hours, turned it off, examined the effects of the experiment, and then permanently enabled IPv6 on its main page. Two major websites in Norway did a similar test, and they also have enabled IPv6 permanently. An activity like this for many websites is clearly a step toward regular and normal IPv6 operations. Website owners will, of course, determine when it makes sense for their business to make IPv6 operations available permanently.

Since the announcement of World IPv6 Day, many other websites from around the world have indicated that they are deploying IPv6, and many of those have decided to join in the global IPv6 test on June 8. The list of websites includes major websites such as Google, Facebook, and Yahoo! and very small websites with small numbers of visitors. It is exciting that websites from every inhabited continent plan to participate. Major websites from the Czech Republic, Portugal, Brazil, and Japan, for example, are joining this test, with more websites joining every day.

For further information about World IPv6 Day, please visit:

There you will find details about the websites that will be turning on IPv6 on June 8, how to join, and information for networks and individuals, including an FAQ.

PHIL ROBERTS joined the Internet Society (ISOC) in 2008. Prior to that he spent several years with Motorola in research and product development, all in the area of mobile broadband systems. He has been active in the IETF for more than a decade. He can be reached at: