The internet will soon be running out of IP addresses, which means that we inevitably will have to move to IPv6 addresses very soon. There are supposedly 91 million addresses remaining, which might seem like a lot, but considering the number of devices coming online each day, these addresses will only suffice for around a month or two. After that, no new devices will be able to connect to the internet.
A few popular services namely Google, Facebook, Yahoo! and Akami have decided to test out IPv6 on the 8th of June this year along with the Internet Society, an organization which handles internet standards. The exercise is being done to eliminate any issues that might crop up during the worldwide transition to IPv6. IPv6 currently has provision for about four billion IPs. Moving to IPv6 will allow four billion times that number. Google has already been running an IPv6 server (http://ipv6.google.com) since 2008. During the test, sites such as Google and Youtube.com will run on a separate IPv6 server.
If you want to see if your device or system is IPv6 ready, visit Test your IPv6 connectivity.