Today is IPv6 Day, and you probably didn't notice. That's good, because if you had noticed--because your Internet wasn't working the way it usually does--the solution for allowing the enormous growth of the Internet would have suffered a setback.

So what is IPv6? It's a way of allowing more IP (Internet protocol) addresses. Every device on the Internet has an address, but in the past, each address was limited to 32 bits of information. IPv6, which will replace this old system (called IPv4), will allow IP addresses with 128 bits of information. That means the new system will allow more than a billion times as many addresses--and therefore devices on the Internet--than we currently have available. The world was running out of IP addresses, so something had to be done.

IPv6 has been under development since 1996, and today, which has been dubbed World IPv6 Day by the tech community, is the first day the new protocol has been tested widely. Several large content providers, including Google, Facebook, Yahoo! and Limelight, are participating.

Thus far, only a small percentage of users have experienced problems, as was expected. So, Happy IPv6 Day. It may seem invisible and unimportant, but if it hadn't gone well ... well, you wouldn't be reading this.