Each host in a network is identified by a logical IP address. The IP address is a network layer protocol and has no dependence on the data link layer address. A unique IP address is required for each host and network component that communicates using TCP/IP protocol suite. It identifies a system’s location on the network through uniform format. Each IP address includes a network ID and a host ID. The network ID identifies the systems that are located on the same physical network bounded by IP routers. All systems on the same physical network shall have the same network ID. The host ID, on the other hand identifies a workstation, server, router, or other TCP/IP host within a network.
An IP address is 32 bits long addressing system in computer networking. Moreover, it segments the 32 bits of the IP address into four 8-bit fields named as octets. Each octet is converted to a decimal number in the range 0-255. IP addressing comprises the following classes: Class A (1- 126), Class B (128 – 191), Class C (192 – 223), Class D (224 – 239), Class E (240 – 255)
Class-based address has its own limitations, which are addressed by the classless addressing scheme dubbed as supernetting. The drawbacks of classed based IP addressing includes:
- Lack of internal address flexibility
- Inefficient use of address space
- Challenges in proliferation of routing table entries
- Lack of or low granularity
- Exhaustion of IPv4 address space
- Difficulty in leveraging and coping with the increased demand for connectivity