Note: (1) 127 Network Address reserved for loopback test. With scarcity of IP addresses, the class-based system has been replaced by Classless Inter- Domain Routing (CIDR) to more efficiently allocate IP addresses. The computers identify the class by first 3 bits (A=000, B=100, C=110), while humans identify the class by first octet(8-bit) number.

Traditionally IP network is classified as A, B or C network.

The host address can further divided into subnetwork and host number. The network address determines how many of the 32 bits are used for the network address and the remaining bits are used for the host address. An example of IPv4 address is 216.3.128.12, which is the IP address previously assigned to .ДЄn IPv4 address is divided into two parts: network and host address. An IP address is written in 'dotted decimal' notation, which is 4 sets of numbers separated by period each set representing 8-bit number ranging from (0-255). A new version of the IP protocol (IPv6) has been invented to offer virtually limitless number of unique addresses. A 32-bit number is capable of providing roughly 4 billion unique numbers, and hence IPv4 addresses running out as more devices are connected to the IP network. The traditional IP Address (known as IPv4) uses a 32-bit number to represent an IP address, and it defines both network and host address. An IP address is analogous to a street address or telephone number in that it is used to uniquely identify an entity. Any device connected to the IP network must have a unique IP address within the network. The Internet Protocol Address (or IP Address) is a unique address that computing devices such as personal computers, tablets, and smartphones use to identify itself and communicate with other devices in the IP network.

Loopback ip address