IPv4 address: Structure and examples

IP address explained

Each component that is included in a network needs an IP address as an identifier. To connect to the Internet, you receive from your Internet service provider (ISP) a public IP address. To operate successfully, servers have a public IP address too. In other cases, computers, devices, smartphones require a private IP address to connect to a private network.

IP addresses help with identifying devices connected in any kind of communication. Furthermore, they give information about the location of the devices in the network, making them capable of exchanging data and communicating.

What is IPv4 address?

Can you imagine IPv4 has been around since the early 80s? It is the 4th version of Internet Protocol which was launched in 1981. Its purpose is to set the rules for communication, such as how the data packets should be sent or how they should have to be received. 

IPv4 has one key characteristic, which is to apply the best-effort delivery model. It is not required to set prior adjustments between the two endpoints for the connection to operate successfully. Instead, it is possible to try to send a message and not wait to notice if it was sent successfully or not. That is the reason why it is excellent for the Internet.

IPv4 addresses are short and actually easy to use. They serve as an ID card of any connected host.

Structure of IPv4 address 

Every IPv4 address has a structure, which looks like that: x.x.x.x. The x represents an octet and is a decimal value from 0 to 255. Periods separate the different octets. Thus, each IPv4 address includes four octets and three periods. The IPv4 address is a 32-bit number and uniquely recognizes a network interface on a machine. The digits are formatted as four 8-bit fields divided by periods. Thus, every 8-bit range describes a byte of the IPv4 address. This way of interpreting the bytes of an IPv4 address is commonly introduced as the dotted-decimal format.

These are simple examples of valid IPv4 addresses:

  • 1.2.3.4
  • 31.142.173.104

The bytes regarding the IPv4 address can be divided even further into two parts. The first one is the network part, and the second one is the host part. 

Let’s take, for example, the IP address 1.2.3.4 

The first component characteristic of a typical IPv4 address, the network part, is represented with the first two octets and first two periods –  1.2.3.4 

The other component, the host part, is expressed with the third and fourth octets and the third period – 1.2.3.4

Network Part

The network part defines the specific number, which is delegated to a particular network. Furthermore, it also can identify the class selected for the network.

Host Part

The host part of the IPv4 address is the one is selected for every host 

With it is possible to identify a specific individual device on a particular network. It is important to know that for every host on your network, the network part of the IPv4 address will be identical, and the host part is going to be different.