IPv6, for those unfamiliar, is the Internet Protocol version 6, the next evolution of network addressing and the internet. Just like Bill Gates’ famous statement about 640KB being all that we’d ever need in computing, so the designers of IPv4 (Internet Protocol version 4) thought of the 4.3 billion addresses in the 32 bits of IPv4. Surely that’s enough! Nearly one per every person on earth?!? But how many of us have a smart phone (iPhone, Android, BlackBerry, etc), a home computer, an Xbox or PS3…not to mention any internet-connected devices at your place of employment?
Those 4.3B quickly disappear, especially when a lot of blocks were eliminated from distribution from day 1 (10.x.x.x, 172.16.x.x-172.31.x.x, 192.168.x.x, and all the multicast and experimental chunks). Add to that the Class A’s (16 million address blocks) wastefully given to large corporations, and you can see where the addresses went. Two weeks ago, the last Class A and thus, the last allotment from the centralized addressing authority, IANA, was dispensed. In technical terms, IPv4 is officially spent. Sure, ISPs still have supplies, but those are now a non-replenishable resource.
Enter IPv6. 128 bits of addressing glory. The IETF (Internet Engineering Task Force) decided that once was enough with regards to running out of space (at least until we expand to other worlds). How many addresses is that, you ask?