Reading Time: 4 minutes

You know what IP address is, right? It is a numerical label assigned to the devices connected to the network so that they can use it for communication. It seems simple, but here’s where things get complicated: These numerical digits are actually divided into multiple IP address classes, with each denoted with an alphabet like “A,” “B,” “C,” “D” and “E.”

These IP address classes have a unique range of IP addresses (which by the way, reflects the number of devices you can connect to your network). Most people on the internet use IP addresses from classes A, B and C, while the IP addresses from classes D and E are reserved for special use. Sounds interesting, right? Do you know which class your IP address falls into?

Check out our guide to learn about different classes of IP addresses. And which class does your IP address belong to?


IP Address Classes Chart

ClassAddress RangeSubnet maskingMax number of networksLeading bitsExample IPUsage
IP Class A1 to 126255.0.0.012881.1.1.1Used for a large number of hosts.
IP Class B128 to 191255.255.0.01638416128.1.1.1Used for the medium-size network.
IP Class C192 to 223255.255.255.0209715724192.1.11.Used for local area network.
IP Class D224 to 239NANANANAReserve for multi-tasking.
IP Class E240 to 254NANANANAThis class is reserved for research and Development Purposes.

What is an IP Address?

An IP (Internet Protocol) address is a unique numerical address assigned to all the devices connected to a network for communication. The communication is being done in the form of IP packets to ensure the packets reach the right destination.

Basically, IP addresses are like the phone numbers your computer uses to talk to connected devices. They also serve as an identifier of a specific device linked to a particular network. Moreover, these addresses help establish a virtual connection between a source and a destination.

IP addresses are usually expressed as a set of four numbers or Octets – For example, 192.911.2.34. Each number can range from 0 to 255.

Four-Octets-of-IP-address-classes

Each IP address is divided into two parts:

  1. Prefix: Also known as a network address, it is the initial part of the IP address that reflects the physical network to which the computer is connected.
  2. Suffix: Also known as the host address, it is later part of the IP address that is associated with the individual device on the network.

Classes of IP Address

Back in 1993, RFC 91 introduced a new addressing architecture which they call “Classful addressing.” This method divides the IP address into five separate classes based on the four IP address bits.

According to this classification, IP addresses from classes A, B, and C are associated with three different network sizes. Class D is only used for multicast, and Class E is reserved for experimental usage. Let’s dig in further to learn more about these types of IP address classes.

Class “A” IP Addresses

IP addresses from class A are associated with networks that have a huge number of hosts. In a network of Class A, the first 8 bits (also known as the first octet) represent the network, and the rest of the 24 bits identify the host in that network.

Class-A-IP-address

In Class A IP address, the first bit of the 1st octet is set to 0 (zero).

Here’s an example of a Class A address: 102.168.212.226. In this example, “102” represents the network and 168.212.226 denotes the host.

A Class A address that begins with 1 and ends at 127 is called a loopback IP address. These types of IP addresses are not supposed to be used and are only reserved for diagnostic purposes.

Class “B” IP Addresses

IP addresses from Class B are for average to large-scale networks. About 16,384 networks are allowed in this IP address class with the initial two octets representing the ID of a particular network.

Note that these binary addresses usually begin with 1 0. So, the rest of the six bits – combined with the second octet – represent the network ID. Similarly, the 16 bits in the last two octets stand for the host ID, which permits about 65,000 hosts on each network.

Class-B-IP-Address

In Class B IP address, the first two bits in the first octet are always set to 1 0.

Check out the Class B IP address example here: 168.212.226.204, where “168 212” represents the network, and “226.204” indicates the Host ID.

Note that the number 127 indicates a loopback IP, which is used for internal testing on the local devices.

Class “C” IP Addresses

IP addresses belonging to Class C are for small networks. This class permits around two million networks with the initials of the first three octets symbolising the network ID.

In Class C IP address, binary digits “1 1 0″ are usually comprised of the first three bits of the very first octet, which were combined with the remaining 21 bits of three octets to represent the network ID. In the same manner, the last octet consisting of 8 bits represent the host ID, which permits about 254 hosts per network. This IP ranges from 192 to 223.

Class-C-IP-Address

The first three bits in the first octet of this IP are ” 1 1 0″, which indicates a Class C IP address.

Here’s an example of a Class C IP address:

192.168.178.1

Class “D” IP Addresses

IP addresses from class D are not assigned to hosts but instead used for multicasting applications. Multicasting is basically a phenomenon that allows a single host to send a series of data to multiple hosts across a particular network at once.

It is mostly used in cable TV networks for video and audio streaming or for delivering real-time data to a network of similar companies.

Note that these addresses are never used for regular networking operations. The first three bits always begin with “1” in a Class D IP address, and their fourth bit consists of “0“.

Class-D-IP-Address

This Class D IP address shows that the first four bits of the first octet are set to 1110.

Here’s an example of a Class D IP address:

227.21.6.173

Class “E” IP Addresses

Class E IP addresses are neither assigned to hosts nor used for regular networking operations. These addresses are reserved for research purposes only.

In a Class E IP address, the first four bits are set to 1, ranging from 240.0.0.0 to 255.255.255.255. Because of its unidentified usage, many network providers nullify these addresses and regard them as undetermined or illegal.

Here’s the Class E IP address example:

243.164.89.28

Pro Tip: You can change your IP address by using a reliable VPN tool. For example, you can change your Canadian IP address to the Italy IP address just by connecting to a VPN server.


IP Address Classes Ranges

IP address ranges for each class are mentioned below:

Class A Public and Private IP Address Range

  • Private IP Range: 10.0.0.0 to 10.255.255.255
  • Number of Hosts per Network: 16,777,214
  • Subnet Mask: 255.0.0.0 (8 bits)
  • Number of Networks: 126
  • Public IP Range: 1.0.0.0 to 127.0.0.0
    • First octet value range from 1 to 127

Class B Public and Private IP Address Range

  • Private IP Range: 172.16.0.0 to 172.31.255.255
  • Number of Hosts per Network: 65,534
  • Number of Networks: 16,382
  • Subnet Mask: 255.255.0.0 (16 bits)
  • Public IP Range: 128.0.0.0 to 191.255.0.0
    • First octet value range from 128 to 191

Class C Public and Private IP Address Range

  • Private IP address classes range: 192.168.0.0 to 192.168.255.255
  • Number of Networks: 2,097,150
  • Number of Hosts per Network: 254
  • Subnet Mask: 255.255.255.0 (24 bits)
  • Special IP Range: 127.0.0.1 to 127.255.255.255
  • Public IP Range: 192.0.0.0 to 223.255.255.0
    • First octet value range from 192 to 223

Class D Public and Private IP Address Range

  • Range: 224.0.0.0 to 239.255.255.255
    • First octet value range from 224 to 239
  • Number of Hosts per Network: Multicasting
  • Number of Networks: N/A

Class E IP Address Range

  • Range: 240.0.0.0 to 255.255.255.255
    • First octet value range from 240 to 255
  • Number of Hosts per Network: Experimental/Research/ For Unique or undefined use
  • Number of Networks: N/A

Note: Check out the difference between Private and Public IP addresses from our informative guide.


FAQs — IP Address Classes

You can figure out the class of an IP address by checking out at its first octet. For example, Class A IP address always use 0-127 as their first octet and a default subnet mast of 255.0.0.0.

IP addresses of class D and class E are used for experimental purposes. They are not allocated to hosts and cannot be used for regular networking operations.

There are five IP address classes: A, B, C, D, and E. Each class has a particular range of IP addresses representing the network size, number of hosts and network.


Conclusion

IP address classes are the division of IP addresses based on the first bits of their octets. Class A, B and C represent large, medium and small networks, respectively, whereas IP addresses from Class D are for multicasting applications. On the other hand, Class E IP addresses are used for special purposes such as experimenting or researching.

Hope this clears up your concept about different classes of IP addresses. If you have any queries, hit us up in the comment section below.