What is IPv6?

IPv6 (Internet Protocol version 6) is the new version of IP designed to replace IPv4. Why? You may ask.

First, A Brief History of IPv4

IPv4 is described in IETF (Internet Engineering Task Force) RFC 791 which was originally published in 1981. IPv4 uses 32 bits for addressing which allows for over 4 billion unique addresses. At the time this seemed like an unlimited resource but with the explosion in popularity of the protocol and the Internet itself, that unlimited resource soon began to run out. Several enhancements such as CIDR (Classless Inter-Domain Routing) and NAT (Network Address Translation) delayed the inevitable depletion of IPv4 addresses, but those were only stop gap measures and not a solution to the problem.

Along Comes IPv6

The IETF developed IPv6 which is described in RFC 2460 to deal with the exhaustion of public IPv4 addresses. The most important enhancement to IPv6 is the sheer number of available addresses. Using 128 bits for addressing, IPv6 has over 340 undecillion (3.4 X 1038) possible unique addresses. To put that number in perspective (if that’s even possible), it’s equivalent to roughly 9,903,520,314,283,042,199,192,993,792 unique addresses for each of the 6.5 billion people alive on Earth at the time of this article. With this many addresses available in the new IPv6 protocol, it’s hard to imagine ever running out of them.

There are many other enhancements to IPv4 in the IPv6 protocol and we’ll go over those in future blog posts.