The unique identifier of a machine (Computer, printer etc) on a computer network which uses TCP/IP protocol for communication is called IP address. There are two types of IP versions are in use, one is IPv4 and another one is IPv6. IPv4 address has a size of 32 bits and consists of 4 decimal numbers separated by dot, each part ranging from 0 to 255 and is a group of 8 bits, for an example 220.127.116.11. In IPv4, there are 232 possible combinations which offer a total of 4,294,967,296 unique addresses. On the other hand IPv6 has a size of 128 bits and approximately 3.403x1038 unique addresses, a typical example of IPv6 address is 0:0:0:0:0:ffff:f37:63ff.