World IPv6 Day and Windows

 has a great post out on some more detail on our support for World IPv6 Day coming June 8…


To ensure that these issues are avoided, the Internet is transitioning to the new protocol, Internet Protocol version 6 (IPv6). IPv6 offers a tremendous number of unique addresses – more than a billion per person! We’ll hopefully never run out. Websites and Internet experiences will gradually transition to this new system of communication, and we’re confident that prudent IPv6 migration will ensure that the Internet continues to function and grow.
On June 8, 2011,,, along with Internet properties from a host of technology companies, will be participating in World IPv6 Day. Most websites today only support IPv4, but on World IPv6 Day participating Internet properties will additionally enable connectivity via IPv6, going “dual-stack.”
This one-day test will enable the Internet community to evaluate the general state of IPv6 preparedness. We want to validate that all of the hardware and software that participates in Internet communication is able to transition smoothly. Laptops, home routers, web servers, network load balancers – there are a lot of things that need to checked for robust and scalable IPv6 support.
Most people won’t even notice World IPv6 Day. If you have no IPv6 connectivity, then you will continue to work as before. If you happen to have IPv6 connectivity, then your connectivity to participating websites will automatically shift over to IPv6. Here at Windows, we’ve been working on IPv6 support since Windows XP. Windows Vista and Windows 7 are automatically enabled to use IPv6 when it is provided by your ISP and your local network.
IPv6 “Brokenness”  Again, most people will be fine on IPv6 Day. But not necessarily everyone – one thing that we hope to assess and isolate is how many users might lose network connectivity when accessing web sites that support dual IPv4 and IPv6 connectivity, a situation called “IPv6 Brokenness.” For example, it is possible that a misconfiguration of your Internet connection can make it hard for your computer and browser to pick the right IP address to contact. This problem might require usage of the IPv6 Brokenness fix that we have made available on Knowledge Base.
Current indications show that this affects less than 0.1% of Internet users. The below test can help you understand whether you will be negatively affected, as well as whether you have IPv6 web access.
It’s important to note that this is a basic test of your computer, its configuration, its local network, and the connectivity provided by your ISP. A negative test at a coffee shop isn’t necessarily informative of the experience at your home.