IP Addresses Explained

Every computer has an exclusive number associated in order to be able to work properly and efficiently on the internet or in any local network. This exclusive or unique number is called an address because it makes possible for a computer to be identified, recognized by other computers and also to communication with them.

This unique address is called an IP address (Internet Protocol address) that computers make use of in order to identify and converse with each other on an internet network.

This address is in the form of XXX . XXX . XXX . XXX where XXX is an integer number between 0 and 255. An IP address shows two things: first the network to which the computer fits in and the host, which is the number of the computers. IP addresses can be classified as private IP addresses (where computers are not connected directly to the Internet) and public IP addresses (where computers connected directly to the Internet).

An IP address can be static or dynamic. Static IP addresses are allocated by the system administrator to every computer and dynamic IP addresses are allocated by another device connected to the network. When the computer is linked to a local area network (LAN), for instance in the corporate network or at home, the IP address is decided while organizing the network and is generally static. Such IP addresses can be, for example, 192.168.0.1, also known as private IP addresses. On the other hand, when connecting to the internet network, the Internet Service Provider (ISP) decides the IP address which will recognize your PC when it is connected via modem to the internet, known as a public IP address. IP addresses for linking to the internet, considered a wide area network (WAN), and can be dynamic or static, depending on the Internet Service Provider.

So, IP addresses are now classified in classes as given below:

Class A: An IP addresses between 1.0.0.0 and 127.255.255.255. The first byte recognizes the networks, the next 3 bytes the host. For example, here we have 127 networks and 16.777.216 hosts.

Class B: IP addresses between 128.0.0.0 and 191.255.255.255. The first 2 bytes recognize the networks, the next 2 bytes the hosts. Here the first byte is restricted to 128 – 191, so we have 65536 hosts and 16384 networks.

Class C: IP addresses between 192.0.0.0 and 223.255.255.255. The first 3 bytes recognize the networks, the last byte the hosts.

Class D: it is used when just one host is propagating and all the others are receiving.

Class E: Only for the future utilization

Now, how are IP addresses created?
IP addresses are supervised and created by the Internet Assigned Numbers Authority (IANA). The Internet Assigned Numbers Authority generally assigns super-blocks to Regional Internet Registries, who in turn assign smaller blocks to Internet service providers and the enterprises.

Thus to conclude, an IP address is a unique identifier for a computer or device on a TCP/IP network which is required so that computer can be recognized and can communicate with other computers in an internet network.