For those of you that don't know about IP addresses, here's a very quick lesson. In order for one computer to talk to another computer on the internet, it needs an address, the same as you have an address so that people know where to send you junk mail catalogs. Human beings suck at remembering numbers, so a system of connecting names to numbers exists (called the Domain Name System, or DNS.) But the core underlying structure is computers talking to each other via numbers that run from 0.0.0.0 to 255.255.255.255. This system is called IPv4, or Internet Protocol Version 4. If you're quick at math, IPv4 has 232 possible addresses. That's 4,294,967,296, four billion, plus. That's seems like a lot. But guess what? It's not nearly enough. Certainly not enough for a world with increasingly connected devices - things we'd never considered 20 or so years ago, like your TV and your refrigerator, let alone millions and millions of cell phones. Right now, most people in the US own at least 2 or 3 devices that need an IP address - your computer, your laptop, your phone, your tablet, your cable box, etc. We've known for years (since the 80's) that we'd run out of IPv4 addresses sooner or later. Well, later has come. IANA (Internet Assigned Numbers Authority) has now given out all of the IPv4 address blocks it has. Unallocated IPv4 addresses will run out in August of this year. Yes, this year (right after my birthday, in fact.) So what's next? What do we do in this situation? In comes IPv6. It's a new and improved internet Protocol, IPv6. IPv6 has a different numbering scheme. It is in hexadecimal. Addresses range from 0:0:0:0:0:0:0:0 to ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff. This allows for 3.4 x 1038 addresses. Officially, that is 340 undecillion, but that's really gazillions and gazillions. But IPv6 is no longer in the future the way it used to be. It's NOW, and you have no choice but to deal with it. Luckily, most of you reading this blog shouldn't have to worry too much - although if you have older hardware (computers, cable modems, routers, etc.) you may be in a bit of trouble when your ISP does the switchover. For most folks who have reasonably recent hardware, the issues sits entirely with your ISP. June 8, 2011, is being called "World IPv6 Day." If you own a website (VPS or server inside your firewall) you may well have work to do. Check with your hosting provider or ISP to find out what you need to do to make sure you're ready.