Internet Protocol version 6 (IPv6) is a network layer protocol for packet-switched internetworks. It is designated as the successor of IPv4, the current version of the Internet Protocol, for general use on the Internet.
The main improvement brought by IPv6 is the drastic increase in the number of addresses available for networked devices. IPv4 supports 232 (about 4.3 billion) addresses, which is not even enough to give one address to every living person, let alone to embedded and portable devices. IPv6, however, supports 2128 (about 34×1037) addresses, or approximately 5×1028 addresses for each of the roughly 6.5 billion people alive today.
This large number of addresses gives extreme flexibility in the assignment of addresses of devices, allowing, for example, each mobile phone to have its own address without the complexity of IPv4 variable-length prefixes, let alone network address translation.
