What Does An IP Address Look Like?

There are 2 versions of IP address in use today, IPv4 which has been in use since the early 80s, and IPv6 which is due to replace the current IPv4 system in the near future due to the lack of IPv4 addresses available.

What Does An IPv4 Address Look Like?

Here is an example of a typical IPv4 address:

The IPv4 address is grouped into 4 seperate decimal numbers, seperated by dots rangeing from 0 - 255

IPv4 Addresses are oganised into 5 different classes as below.

Class A: -
Class B: -
Class C: -
Class D: -
Class E: -

Classes A - C are used for general IP communication between computers and routers, whilst classes D and E are reserved for multicasting and experimental purposes.

What Does An IPv6 Address Look Like?

Here is an example of an IPv6 Address: 2001:CDBA:0000:0000:14AF:0000:0412:00BB

The IPv6 address is arranged into 8 seperate groups, consisting of 4 hexadecimal digits seperated by a colon. As hexademical is a base-16 number, each digit ranges from 0 - 9 and A - F.

As you can see the above IPv6 address is alot longer than the IPv4 address and more difficult to remember.
However, the engineers who developed the IPv6 system came up with a couple of rules that can make the IPv6 address shorter by eliminating zeros.

The first rule states you can use "::" to remove one or more groups of concsecutive zeros (0000)
But this can only be used once per IPv6 address.

If we use the example of: 2001:CDBA:0000:0000:14AF:0000:0412:00BB

This shortened address can become: 2001:CDBA::14AF:0000:0412:00BB or 2001:CDBA:0000:0000:14AF::0412:00BB

The second rules states you can eliminate leading zeros in a group until the group starts with a digit other than a zero, or if the final digit in a group is a zero. This can be used as many times as you like in an IPv6 address, you can also combine this with the first rule.

Let us take the same example: 2001:CDBA:0000:0000:14AF:0000:0412:00BB

Using the second rule, the IPv6 address can become: 2001:CDBA:0:0:14AF:0:412:BB

Using the first and second rules: 2001:CDBA::14AF:0:412:BB

All of a sudden, the IPv6 address becomes alot easier to digest.