This coming Wednesday (June 8, 2011), around 300 websites - including Google, Facebook, Yahoo!, Bing - are testing the IPv6 readiness of the internet. For 24 hours "test flight", these participating websites will offer their contents over IPv6. The test will consist of the participating websites publishing their DNS AAAA record and connecting IPv6 capable users through IPv6.
According to the Internet Society, which is organizing the test,
The goal of the Test Flight Day is to motivate organizations across the industry – Internet service providers, hardware makers, operating system vendors and web companies – to prepare their services for IPv6 to ensure a successful transition as IPv4 addresses run out.
In preparation for the event, Google is already preparing users by notifying them of the upcoming test and suggesting that they test if they are IPv6 ready.
Clicking on the Try It Now link in the notification will take users to a page which tests if they are ready for IPv6 or not. (You can also click here to test.)
What to do if you are not IPv6 ready?
Most of the modern Operating Systems already support IPv6. So, there should be no problem from the software. However, users might not be IPv6 ready because of their network infrastructure.
Even if the test, shows that you are not IPv6 ready, there is no reason for you to worry. The participating websites will use IPv6 only for the users who are IPv6 ready. Those who are not ready will continue to get contents through IPv4.