What is IPv4?
Internet Protocol version four, or IPv4, is a system of addresses used to identify devices on a network. Originally described in 1981 in RFC791, IPv4 is the most widely used Internet layer protocol, and at this point is used by the vast majority of users to connect to the Internet.
IPv4 addresses are actually 32-bit numbers. This means that there are 232, or just over four billion, possible addresses. Over time, however, it has become clear that more addresses than this will be required to ensure ongoing growth of the Internet. The unused pool of IPv4 addresses is predicted run out in the next two years, so an alternative is required.
IPv4 exhaustion
On 3 February 2011, the IANA allocated the final five /8s of IPv4 address space to the five Regional Internet Registries (RIRs). The Number Resource Organization (NRO), representing the five RIRs, issued the following statement:
The video below is from the ceremony and press conference that took place in Miami, USA, on 3 Feburary 2011, featuring the heads of ICANN, IANA, the five RIRs, the Internet Society and the IETF.
