You may have heard already - we have run out of IPv4 addresses. An IPv4 address is 32 bits long and looks like this: 37.187.192.179. If you count up all the possible combinations (considering each section may be between 0 and 255), missing out the addresses reserved for special purposes, you get about 3,706,452,992 addresses.

The new system that the world is currently moving to (very slowly mind you) is called IPv6 and is 128 bits long. They look like this: 2001:41d0:52:a00::68e. This gives us a virtually unlimited supply of addresses so we should never run out.

The problem is that the world is moving far too slowly over to it and you can never be sure if you have IPv6 connectivity or not. I built a quick IP version tester to solve this problem. I know there are others out there, but I wanted to build one myself :)

You can find it here: Ip Version Tester.