IPv4 and IPv6 Overview

IP stands for internet protocol. The internet protocol is the protocol which allows internetworking at the internet layer of the internet protocol suite. IPv4 is the fourth version of the protocol and IPv6, as the name implies, is the sixth version.


IPv4 is the fourth version of IP. It was bought into action by deploying on SATNET in 1982 and on the ARPANET in January 1983. As compared to IPv6, IPv4 still is widely used and contributes almost 95% of internet traffic to date. 

IPv4 provides addressing capability of approximately 4.3 billion addresses. It works as a network layer of ISO-OSI models. Being a connectionless protocol, it makes the best effort to deliver the packet to the destination.

IPv4 address range

IPv4 has an address of 32 bits. The address is divided into four parts, each part separated by a dot. Each part is known as an octet, so there are four octets in an IPv4 address. For example: The range of each octet is 0-255.

IPv4 address classes

IPv4 addresses have been divided into various classes depending on the range of IP addresses. They are as follows:

  1. Class A – 1.XXX.XXX.XXX – 127.XXX.XXX.XXX
  2. Class B – 128 XXX.XXX.XXX – 191. XXX.XXX.XXX
  3. Class C – 192.XXX.XXX.XXX – 223.XXX.XXX.XXX
  4. Class D – 224.XXX.XXX.XXX – 239.XXX.XXX.XXX
  5. Class E – 240.XXX.XXX.XXX – 255.XXX.XXX.XXX

Private IP ranges

The following IP ranges in IPv4 are private IP addresses and are used internally within the network:

  • –
  • –
  • – 192.168. (Read more...)

*** This is a Security Bloggers Network syndicated blog from Infosec Resources authored by Nitesh Malviya. Read the original post at: http://feedproxy.google.com/~r/infosecResources/~3/ld2ZCbj5Vbg/