There are 3 IP address classes: A, B, C.

To ensure smooth execution of the entire process, every machine connected to the internet receives a unique ‘IP address’, which serves as an internet user’s internet identification number.

Seems simple? Let’s dive deeper.

Let’s begin with the basics.

What Is An IP Address?

While you frequently use the internet for various activities, did you ever wonder how the websites you visit identify your presence? It is done through your IP address.

The entire communication on the internet runs under an address of Internet Protocol (IP). This IP primarily determines the way of packetizing, routing and transference of data on the internet.

Every desktop, laptop, smartphone, or any other device connected to the internet has its own unique IP address, which serves the purpose of its identification while networking.

Just as your home or office address determines your physical location, your IP address marks your online presence, facilitating in the exchange of information over the internet.

Technically, the IP address includes two kinds of addresses – the network address and the host address.

Network address identifies the ‘network’ to which all hosts are connected. Whereas, the host address corresponds to the ‘host’ or the specific machine.

IP Address Format

There are two main standards of IP address – IPv4 and IPv6. At present, most online devices use IPv4, whereas, IPv6 is merely a new system that is yet to take over. So, we basically focus on IPv4 system in this article.

In the case of IPv4, the IP address is a 32-bit long numerical string divided into four parts. Every part, an ‘octet’, contains 8 bits. Every octet is a decimal representation of an eight-digit binary number. Hence, the usual format of an IP address follows 0.0.0.0.

For instance, 107.170.127.117, or 216.27.61.137. With this scheme, the highest value for an IP address is 232 or 4294967296. It means with IPv4, the internet can recognize around 4.3 billion devices with unique IP addresses.

what is ip address ipv4

To deal with IPv4 exhaustion, Internet Engineering Task Force (IETF) developed the new version of IP address, better known as IPv6.

The main advantage of IPv6 over IPv4 is its larger address space. The length of an IPv6 address is 128 bits, compared with 32 bits in IPv4.

The address space therefore has 2128 or approximately 3.4×1038 addresses (340,282,366,920,938,463,463,374,607,431,768,211,456, which is approximately 340 undecillion, or 340 billion billion billion billion, addresses).

IP Address Classes

As stated above, the present IP address standard can manage roughly 4.3 billion devices. This is quite a large number, particularly when one has to locate a single IP address. Therefore, it has been categorized into separate classes for the ease of identification.

Precisely, there are five classes of IP address based on the numerical order. Besides, these classes also have differences in the number of bits reserved for the network address and the home address.

  • Class A: The value of the first octet ranges from 1 to 126, that is, from 1.0.0.1 to 126.255.255.254. Here, the first octet represents the network address (8-bit), whereas the remaining three represent the host address (24-bit). This IP address class can support up to 16 million hosts connected with each of the 127 networks.
  • Class B: The value of the first octet ranges from 128 to 191. Hence, the IP addresses falling in this class include 128.1.0.1 to 191.255.255.254. In Class B, the first two octets represent the network address (16 bit), and the last two represent the host address (16-bit). The Class B can support 65,000 hosts across 16,000 networks each.
  • Class C: In Class C, the first three octets represent the network address (24-bit), whereas, the last one is the host address (8-bit). The values of the first octet in this class range from 192 to 223, thus including the IP addresses from 192.0.1.1 to 223.255.254.254. This class can support 2 million networks with 254 hosts each.
  • Class D: It includes IP addresses ranging from 224.0.0.0 to 239.255.255.255. The entire Class D is reserved for multicast addresses (those having multiple recipients).
  • Class E: In this class fall the IP addresses ranging from 240.0.0.0 to 255.255.255.255. Class E is reserved for research purposes and future use.
ClassStarting AddressEnding AddressSubnet mask
A0.0.0.0127.255.255.255255.0.0.0
B128.0.0.0191.255.255.255255.255.0.0
C192.0.0.0223.255.255.255255.255.255.0
D224.0.0.0239.255.255.255255.255.255.255
E240.0.0.0255.255.255.255255.255.255.255

Special IP Addresses

In addition to the IP address classes, some exceptional IP addresses also exist that remain reserved for specific uses. They are never assigned to any device. These Special IP addresses include the following.

  • 0.0.0.0: It is a representative of all networks being the very first IP address.
  • IP address range 127.0.0.0 to 127.255.255.255: It is entirely reserved for loopback or localhost and is used for troubleshooting and protocol testing.
  • 255.255.255.255: It is the last of all IP addresses representing all hosts. It helps in broadcasting purposes to the hosts connected on a network.

Wrapping Up

It is all about the IP address classes. You see, the simple numerical string you view as a representative for your computer has such a fine classification underneath. This categorization of IP addresses facilitates in uniquely identifying billions of devices connected to various networks.

Since it carries some of your personal information, do not forget to take care of it and hide your IP address.

We hope this brief overview will help you in understanding the basics of IP address classes. Do let me know your thoughts about the article in the comment section below.

Write A Comment