IP Address – Internet Protocol address: Basic about IPv4

An IP address (Internet Protocol address) is actually a numerical tag that is assigned to each participating device over the network either a computer or a printer. These devices are attached via networking using internet protocols for their communication.

Two main functions of an IP address are given under:

  1. Identifying a host or a network interface
  2. allocating addresses

The Internet Protocol designers have defined it as 32 bit IP address but this approach is restricted to the IPv4 version which is still in use. Besides this, another approach of 128 bits was introduced in 1995 which later in 1998 standardized as RFC-2460 and is known as IPv6. Details of both are given below.

Two Main Descriptions of IP Addresses

IP addressTwo editions of the IP come into view, these are named as: IPv4 and IPv6 (internet protocol version 6). But the way to define an IP address is different in both cases.

Typically, people are taken the term “IP” in the same way as it is defined in IPv4 (consisted on 32 bits with addresses space limit to 4294967296). For example, is IPv4 address written form. But the binary of this address will be as following 10101100.00010000.11111110.00000010. According to IPv4, a number of addresses are reserved for the private network. Part of addresses has also been reserved for the multicast addressing. But IPv4 addresses can be represented in different forms like: binary, octal, decimal and hexadecimal etc.

IPv4 subnetting

Classful network design was introduced in order to practice multiple network entities assignment and also to permit the further subnetting of each individual network. Moreover, 1st three bits of an IP address (significant octet) were predefined as the address class and three A, B and C classes were reserved for the worldwide unicast addressing.

For class A, the numbers of possible IP addresses per network are as 16777216, for class B, the possible numbers of IP addresses per network are 65536, and for class C, the possible numbers of IP addresses per network are as 256.

But there was lack of scalability in this network design. Therefore, CIDR (classless inter domain routing) system was introduced in 1993 as a replacement of that IP address class system. Later, in the system variable length subnetting mask was allowed for the allocation and routing purposes.

In addition to this, three Pv4 addresses arrays for private networking were preserved in the RFC 1918. As these addresses are never activated over the Internet so their uses require no coordination along with an Internet P address registry. Nowadays, private networks are connected to the Internet via NAT (network address translation) and reserved blocks which are divided into subnets are in used under the surveillance of administrator.

But extra burden on IPv4 address space was driven the IETF (internet engineering task force) to discover the new techniques and technologies so internet’s addressing expansion could become possible. As a result of such effort, in the year 1995 a replacement of Ipv4, named as internet protocol version 6 was introduced. In which 128 bits address size was possible.

Large numbers in IPv6 allow the assignment of large blocks whenever they are needed and appropriate aggregation for well-organized routing. Example of IPv6 address is 2007:0DB8:AC10:FE00:


Static IP addresses are generally assigned to a computer by hand and this job is done by an administrator. But the exact process is varied and is depending upon the platform, running computers. Anyway, dynamic IP addresses can be assigned with the help of computer interface, host software or a server using DHCP (dynamic host configuration protocol). In case of failure of static or DHCP address configurations, IP address assignment job is performed by an operating system with the assistance of state-less auto-configuration.


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