# What is IPV4 address notation and hierarchy of addressing?

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The Internet Protocol version 4 (IPv4) is called the fourth version in the development of the Internet Protocol. Its address is a 32-bit address which uniquely defines the connection that means here each address defines one, and only one, connection to the Internet.

If a device has two connections to the Internet, via two networks, then we call it has two IPv4 addresses.

IPv4 addresses are universal in a sense where the addressing system must be accepted by any host that wants to be connected to the Internet.

## Ipv4 address notation

There are three notations to show an IPv4 address which are as follows −

• binary notation (base 2)
• dotted-decimal notation (base 256)
• hexadecimal notation (base 16)

The three notations to show an IPv4 address are diagrammatically represented below − ### Binary notation

Here, IPv4 address is displayed as 32 bits. To make the address more readable, one or more spaces are inserted between bytes (8 bits).

### Dotted-decimal notation

Here, IPv4 addresses are written in decimal form with a decimal point separating the bytes. Each number in the dotted-decimal notation is between 0 and 255.

Each hexadecimal digit is equivalent to four bits. This means a 32-bit address that has 8 hexadecimal digits. This notation is often used in network programming.

## Hierarchy in IPv4 addressing

The different types of communication network that involve delivery, the addressing system is hierarchical.

A 32-bit IPv4 address is in the form of hierarchical but divided only into two parts as follows −

• The first part of the address is called as the prefix, which defines the network(Net ID).

• The second part of the address is called as the suffix, which defines the node (Host ID).

Usually, the prefix length is n bits and the suffix length is (32-n) bits.

A prefix can be fixed length (or) variable length. The network identifier in the IPv4 was first designed as a fixed-length prefix. This scheme is referred to as classful addressing.

The new scheme, which is referred to as classless addressing, uses a variable length network prefix.

## Categories of IPv4 addressing

There are two broad categories of IPv4 Addressing techniques. They are as follows −