What is IPv4?

How are IPv4 addresses created? What is an IPv4 address?

There are several stages in the history of the creation and development of IP addresses.

In the 70s, employees of the DARPA agency, which is engaged in advanced technologies, decided to work on creating a link between computers. Late in that decade, the development of the first protocol was completed. However, the IP (Internet Protocol) underwent some changes until IPv4 came out. It happened in 1981.

Let's review IPv4 addresses in more detail. IPv4 is the fourth version of IP, it is the basis of the Internet, and establishes the rules for the computer networks functioning on the principle of packet exchange. This protocol is responsible for establishing connections between computers, servers, mobile devices based on IP addresses. Information exchange in IPv4 is carried out through IP packets. An IP packet is divided into two large fields: a data field that carries useful information and a header that contains all the protocol functionality.

IPv4 works on the network layer of the TCP/IP protocol stack. The main task of the protocol is to transfer data blocks from the sending host to the destination host, where the senders and receivers are computers that are uniquely identified by IP addresses.

An IP address is a unique identifier for a device (computer, server) connected to a local network or the Internet. It is used for addressing and transmitting data over the network; without it, the device could not determine where it is worth transmitting data. Each device operating over the network (telephone, computer, network printer, server, etc.) needs its own network address.

An IP address is somewhat like passport data. It is written as four numbers from 0 to 255 (e.g. 172.127.1.2). In fact, for a computer, the address would look like 0222022 00000000 00020000 02000002. IPv4 addresses are most often written as four decimal numbers from 0 to 255, separated by a period (e.g. 172.127.1.2). A minimum possible address is 0.0.0.0 and the maximum, 255.255.255.255. A device without an IP address cannot be identified on the network or exchange information with other devices.

What are the types of IP addresses?

There are several different types of IP addresses. Public IP addresses (white) are addresses on the global Internet. Such addresses are used to access the Internet and to provide access all over the world. Private IP addresses are used to create a local network in offices and enterprises. An Internet provider can use these addresses to save public addresses.

In addition, there are static and dynamic IP addresses. Dynamic IP addresses are public addresses used by Internet providers. These addresses can sometimes result in a shortage for subscribers. When connecting to the Internet, subscribers receive a free IP address. When this subscriber disconnects from the Internet, this IP address is released and may be issued to another subscriber. Static IP addresses are the exact opposite of a dynamic IP address. They are permanently assigned to the subscriber.

The design of IPv4 did not take into account current growth rates in the Internet and the impending depletion of IPv4 address space. Today, the rapid development of the Internet has reached a point where most IPv4 addresses have already been distributed. This has led to the creation of a new IPv6 protocol and Carrier Grade Network Address Translation (CGN or CGNAT), also known as Large Scale NAT (LSN).