Each device on the Internet, suchas a computer or mobile telephone, must be assigned an IP address in order to communicate with other devices. With the ever-increasing number of new devices beingconnected to the Internet, there is a need for more addresses than IPv4 can accommodate. IPv6 uses 128-bit addresses, allowing for 2128, or approximately 3.4×1038addresses — 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 less than one addressper person alive in 2012), but IPv6 allows for around 4.8×1028 addresses per person — a number unlikely ever to run out.
IPv6 addresses, as commonly displayed tousers, 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 isaccelerating, 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 IPv6adoption, 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.