Dear Lifehacker, I've heard that we're running out of IP addresses and we need to switch to a new system called IPv6, but I don't understand any of it. What does this all mean for the internet and for me? Signed, Infinitely Perplexed
The transition from IPv4 to IPv6 is kind of confusing if you've never really read much about it, but the idea is pretty simple. IPv4 is what we currently use, and it results in IP addresses with four sets of numbers. For example, the IP address to your router is probably 192.168.1.1 or 10.0.1.1 (or something similar).
The periods separate each number, and there are a total of four. Because there are only so many combinations, we've actually managed to (essentially) run out of IPv4 addresses. Without IP addresses, we can't keep adding more computers (and other devices) to the internet. That's a simplified explanation of the problem, but that's essentially the issue. The solution is iPv6, which results in longer addresses that look like this: 3ffe:1900:4545:3:200:f8ff:fe21:67cf. This offers up many, many more combinations so we'll be able to allocate new IPv6 addresses for a long time.
How The Change Affects You
It's pretty easy to memorise an IPv4 address—it's not much different than memorising a phone number—but IPv6 addresses are quite a bit more difficult. On the surface, you're dealing with something a bit more complex. Beneath the surface, IPv6 also works a bit differently than IPv4 and requires both hardware and software support to function. IPv6 support is built in to most modern computer hardware, but not all. If you want to check if your hardware supports IPv6, the easiest thing to do is head for the command line. In Windows you can run ipconfig. On a Mac or Linux machine you can run ifconfig. These commands should list IPv4 and IPv6 addresses for your hardware. If you see an IPv6 address listed, you're good.
Software support is also necessary for IPv6 to work. You can't just enter an address like 3ffe:1900:4545:3:200:f8ff:fe21:67cf because, at the moment, your browser probably doesn't recognise the format (or sort of does). Arguably there isn't much to worry about here because, 1) you can't do anything about this and 2) software support will be on its way (though many industry watchers believe that there'll be an uncomfortable transition period).
When The Change Is Coming
In the United States, the IPv6 compatibility deadline set by the federal government is June 30th, 2011 -- but that doesn't mean that everything has to be (or will be) IPv6 ready by then. This is soon; whether you think it's ridiculously soon depends a little on your point of view. If you're running a popular browser, you can expect compatibility by then, but that doesn't mean everything you access in a browser will necessarily work either.
The most important steps you can take are keeping your software up to date and making sure you have IPv6 compatible hardware. While the IPv6 transition won't halt your ability to access the internet, it could cause some issues moving forward.
Hope that helps!