The first version of the Internet Protocol (IP) was developed in the 1970s. It uses 32-bit addresses, which allows for a total of approximately 4.3 billion unique addresses. IPv4 is still widely used today, but it is running out of available addresses due to the rapid growth of the internet.
Address Format
An IPv4 address is a 32-bit numerical address that consists of four octets (8-bit blocks) separated by periods. For example, the following is a valid IPv4 address: 192.168.1.1. Each octet of an IPv4 address can have a value between 0 and 255, which allows for a total of approximately 4.3 billion unique addresses.
Address Notation
IPv4 addresses can be written in decimal notation (e.g. 192.168.1.1) or in hexadecimal notation (e.g. 0xC0A80101).
Address Exhaustion
IPv4 was the first version deployed for production on SATNET in 1982 and on the ARPANET in January 1983. It is still used to carry most Internet traffic today, even with the ongoing deployment of Internet Protocol version 6 (IPv6), its successor. IPv4 uses a 32-bit address space which provides 4,294,967,296 (232) unique addresses, but large blocks are reserved for special networking purposes. This quantity of unique addresses is not large enough to meet the needs of the global Internet, which has caused a significant issue known as IPv4 address exhaustion during the ongoing transition to IPv6.
