IPv6

IPv6 (Internet Protocol version 6) is the latest revision of the Internet Protocol (IP), the primary communications protocol upon which the entire Internet is built. It is intended to replace the older IPv4, which is still employed for the vast majority of Internet traffic as of 2012. IPv6 was developed by the Internet Engineering Task Force (IETF) to deal with the long-anticipated problem of IPv4 running out of addresses.

Each device on the Internet, such as a computer or mobile telephone, must be assigned a number called an IP address, a binary number with a certain number of digits (each presented by one bit), in order to communicate with other devices. With the ever-increasing number of new devices being connected to the Internet, there is a need for more addresses than IPv4 can accommodate. IPv6 uses 128-bit addresses, allowing for 2128, or approximately 3.4×1038 addresses — more than 7.9×1028 times as many as IPv4, which uses 32-bit addresses. IPv4 allows for only 4,294,967,296 unique addresses worldwide (or fewer than one address per person alive in 2012), but IPv6 allows for around 4.8×1028 addresses per person — a number unlikely to ever run out. However, this means the two protocols are not compatible, complicating the transition to IPv6. IPv6 addresses, as commonly displayed to users, consist of eight groups of four hexadecimal digits separated by colons, for example 2001:0db8:85a3:0042:0000:8a2e:0370:7334.

The deployment of IPv6 is accelerating, with a World IPv6 Launch having taken place on 6 June 2012, in which major internet service providers, especially in countries that had been lagging in IPv6 adoption, deployed IPv6 addresses to portions of their users. Data from Arbor Networks showed a peak of 0.2% of Internet traffic on IPv6 during the launch.