I wrote an article about IPv6 a while back.The current Internet protocol, IPv4, will eventually run out of addresses to assign to machines connected to the Internet. Sony’s announcement that it plans to assign IP addresses to all its new products will undoubtedly heat up interest in IPv6. How many addresses can you get from IPv6’s 128-bit header? Here’s one way to look at it: Imagine 1 trillion Bill Gateses standing in a circle (not a pretty picture, but play along for a moment). Now ask each one to convert his fortune into pennies and toss them in a collective pile. If each penny contained 1 trillion tiny computers and each computer had its own IP address, you’d still have used only a fraction of IPv6’s potential space. Link