IPv4 for Internet Protocol version 4. IPv4 codes the addresses on 32 bits and allows to manage about 4 billion IP addresses. These IP addresses are presented as a succession of decimal digits (4 in IPv4), such as 192.168.2.2. From 2011, IPv4 is gradually being phased out, as there are no more possibilities to offer combinations of numbers. IPv4 is replaced by theIPv6.