The term IP stands for Internet Protocol. This protocol is essential for transferring data from one device to another. When data is sent or received on a network, basically that data gets divided into small packets and these packets contain two things – one is the sender’s address and the other is the receiver’s address. The TCP is responsible for putting each piece of packet into a right sequence so that it can be delivered properly to the desired host.
There are a few things that need to be discussed about IP:
IP address has two versions-
IPV4 – IP version 4 is a 32 bit binary address which gets divided into four octets in terms of dots.
IPV4 has 5 classes namely – Class A, Class B, Class C, Class D, Class E.
Class A: Class A addresses have an IP address in which the first octet is between 1 to 126 and the default subnet mask is 255.0.0.0 . In this class of IP the 1st octet represents network ID and the last three 3 octets represent host ID. Each octet can contain 256 possible values (0to 255) which mean class A supports 16,777,216 hosts on the network (256*256*256) but the number of valid hosts are 16,777,214.
127 –Loop back address is used for self-test.
Class B: Class B has an IP address in which the value of the first octet is between 128 to 191 and the default subnet mask is 255.255.0.0 . In this class of IP first two octets represents network ID and the last two represents host ID. That means there can be 256*256 = 65,536 hosts on the network but the valid hosts will be 65,534.
Class C: The range of class C IP starts from 192 to 223 and the default subnet mask is 255.255.255.0 . Accordingly the first three octets of this class represents network ID and the last represents host ID. Having only one octet as the host ID means a class C address can support only (256 to 2) 254 hosts on a network.
Class D: Class D (range 224 to 239) addresses are specially used for multicasting. It means if a particular data needs to be sent to multiple systems simultaneously then it can be done by just sending it to the multicast address and the message will be conveyed to its registered hosts.
Class E This type of address is used for experimental purpose so it is not assigned to networks (240 to 255).
When IPV4 was designed in 1981, no one actually anticipated the growth of internet and the security related issues with it, as a result of at present more options are being looked for like IPV6. Compared to IPV4, IPV6 has 128bit address space which supports a total of 2128 (3.4×1038) addresses and on a security note IPV6 has IPSec as a pre-defined security feature. This type of address is represented in hexadecimals like 2001:DB8:0:0:22:F376:FF3B:AC94.