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In today’s digital world, communication between devices is essential for businesses and individuals alike. From sending emails to streaming videos, all our online activities depend on data transfer between devices. This is where IP addresses come into play: they enable devices to communicate with one another and ensure that data reaches the correct destination. In this article, we’ll explore what IP addresses are and their different classes, why they’re essential for communication between devices, and how they work.
What are IP addresses?
IP addresses, or Internet Protocol addresses, are unique numerical identifiers assigned to devices connected to a computer network. They are essential for communication between devices and for the transmission of internet traffic.
IP addresses work by assigning a unique sequence of numbers to every device connected to the internet. These numbers are used to identify the device and its location on the internet. IP addresses consist of four sets of numbers separated by full stops, and can range from 0.0.0.0.0 to 255.255.255.255.255.255. When a device connects to the internet, the internet service provider (ISP) assigns it an IP address. This IP address enables the device to communicate with other devices and to access websites and other online services.
When data is sent over the internet from one device to another, it is divided into packets. Each packet contains the IP addresses of the sender and the recipient. As the packets travel across the internet, they are routed from one network to another using these IP addresses, and in this way they reach their destination.
Variations of the IP address
There are two types of IP addresses: IPv4 and IPv6. IPv4 addresses are the older of the two and consist of 32 bits, which allows for the creation of approximately 4.3 billion unique addresses. As the internet has grown, the number of available IPv4 addresses has become limited, which led to the development of IPv6. IPv6 addresses consist of 128 bits, which allows for approximately 340 quadrillion, quadrillion, quadrillion, quadrillion unique addresses, ensuring there are enough to accommodate the growing number of IoT and other smart devices.
Classes of IP addresses
Not all IP addresses are the same, and they are classified into different categories based on their characteristics and usage. There are five classes of IP addresses, designated by the letters A, B, C, D and E, each with its own range of values and uses. The first three classes are the most commonly used, and we will discuss them in more detail below.
Class A IP addresses
Class A IP addresses are allocated to large organisations, such as major corporations, universities and government bodies, which require a large number of IP addresses. The IP address range between 10.0.0.0.0 and 10.255.255.255.255 is reserved for private networks, and many large organisations use this range for their internal networks. Class A IP addresses consist of an 8-bit network portion and a 24-bit host portion, which allows for up to 126 networks and more than 16,000,000 host addresses per network. The first bit of the address is always 0, leaving 7 bits to identify the network.
Class B IP addresses
Class B IP addresses are allocated to medium-sized organisations, such as regional internet service providers, which require a moderate number of IP addresses. These consist of a 16-bit network portion and a 16-bit host portion, allowing for up to 16,384 networks and more than 65,000 hosts per network. The first two bits of the address are always 10, leaving 14 bits to identify the network.
Class C IP addresses
Class C IP addresses are allocated to smaller organisations, such as small and medium-sized enterprises and home networks, which only require a few IP addresses. These consist of a 24-bit network portion and an 8-bit host portion, allowing for a maximum of 2,097,152 networks and 254 hosts per network. The first three bits of the address are always 110, leaving 21 bits to identify the network.
Other classes of IP addresses
Class D IP addresses are reserved for multicast traffic, whilst Class E IP addresses are used for experimental and research purposes. These classes are not generally used in typical network configurations.
Summary
IP addresses are essential for communication between devices and for the transmission of internet traffic. The different classes enable the efficient allocation of IP addresses to organisations of various sizes. Understanding the different classes of IP addresses and their uses can help network administrators manage their networks more effectively.