What is Subnetting in Computer Networking?

There is a quite common belief among network administrators that if you want to make your computer network more efficient, you should consider Subnetting. But what is subnetting, and how can it make the computer network efficient?

Many of us might be unaware of these queries. So, in this article, we will discuss all there is to know about Subnetting in computer networking. But, before we explore the term “Subnetting,” let’s go through the list of topics listed under the table of contents (TOC) that we will cover in this article.

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Table Of Contents (TOC)

• What is Subnetting?
• Example of Subnetting
• How Does Subnetting Work?
• Characteristics of Subnetting
• Advantages of Subnetting
• Disadvantages of Subnetting
• What is a Subnet Calculator?
• Conclusion

What is Subnetting?

Subnetting is a technique used in computer networking to divide a single network into multiple smaller networks, known as subnetworks or subnets. The purpose of subnetting is to partition a large network into smaller, more efficient subnets, which can improve network performance, security, and organization.

In a subnetted network, each subnet has its own unique subnet mask and network address. These unique subnet mask and network address allows devices on the subnet to communicate with each other directly without having to go through a router or other networking device. Thus improving communication’s speed and efficiency within the subnet and reducing network traffic on the wider network.

Subnetting is often used in larger organizations, such as companies or universities, to create separate networks for different departments or groups of users. It can also be used to create separate networks for different types of devices, such as servers, workstations, and mobile devices.

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Example of Subnetting

In order to understand the concept of subnetting, let’s go thorugh one more example and in detail. Imagine that you have a network with the following network address: 192.168.1.0/24

This network has 256 possible host addresses, from 192.168.1.1 to 192.168.1.256. However, let’s say that you want to divide this network into two smaller subnets, each with 128 host addresses. To do this, you can create a subnet mask that uses the first two octets (192.168.1) to identify the network, and the third octet to identify the subnet.

For example, you could use the subnet mask 255.255.255.0, which would give you two subnets with 128 host addresses each:

• Subnet 1: 192.168.1.1 – 192.168.1.128
• Subnet 2: 192.168.1.129 – 192.168.1.256

You can also create additional subnets by using a different subnet mask. For example, you could use a subnet mask of 255.255.255.128, which would give you four subnets with 64 host addresses each:

• Subnet 1: 192.168.1.1 – 192.168.1.64
• Subnet 2: 192.168.1.65 – 192.168.1.128
• Subnet 3: 192.168.1.129 – 192.168.1.192
• Subnet 4: 192.168.1.193 – 192.168.1.256

How Does Subnetting Work?

Subnetting works by dividing the host part of an IP address into two or more subnets using a subnet mask. The subnet mask is a series of ones and zeros that determines which portion of the IP address represents the network and which portion represents the host.

In order to better understand it, consider the following IP address and subnet mask:

• IP address: 192.168.1.100
• Subnet mask: 255.255.255.0

The subnet mask comprises four octets (sets of eight bits), each represented by a number from 0 to 255. In this case, the subnet mask is 255.255.255.0, which means that the first three octets (192.168.1) represent the network portion of the IP address, and the fourth octet (100) represents the host portion of the address.

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To determine which subnet an IP address belongs, you can perform a bitwise AND operation on the IP address and the subnet mask. The resulting value will be the network address of the subnet that the IP address belongs to.

For example, if we perform a bitwise AND on the above IP address and subnet mask, we get the following network address:

192.168.1.100 AND 255.255.255.0 = 192.168.1.0

This means that the IP address 192.168.1.100 belongs to the subnet with the network address 192.168.1.0/24.

Characteristics of Subnetting

Here are some characteristics of subnetting:

• Each subnet has its own unique network address and subnet mask.
• Subnetting can improve network performance, security, and organization.
• It divides a single network into smaller subnetworks or subnets.
• It can be used to reduce network congestion and improve network reliability.
• Subnetting allows you to create separate networks for different departments, locations, or types of devices.
• It allows you to add more devices to a network without requiring additional IP addresses or network infrastructure.
• Devices on the same subnet can communicate with each other directly without having to go through a router or other networking device.
• Subnetting requires the use of a subnet mask, which determines which portion of an IP address represents the network and which portion represents the host.

Advantages of Subnetting

There are several advantages of using subnetting in a computer network:

• Improved network performance: By dividing a large network into smaller subnets, you can reduce the amount of network traffic on the main network. Thus, improving communication speed and efficiency within the subnets.
• Enhanced security: Subnetting can create separate networks for different types of devices or users, Thus, helping in improving security by limiting access to sensitive resources.
• Greater network scalability: Subnetting allows you to add more devices to a network without requiring additional IP addresses or network infrastructure.
• Enhanced network organization: Subnetting allows you to group devices by location, department, or other criteria, making it easier to manage and maintain the network.
• Reduced network congestion: By dividing a network into smaller subnets, you can reduce the number of devices trying to communicate over the same network segment. Thus, reducing congestion and improving overall network performance.
• Improved network reliability: By creating redundant subnets, you can improve the reliability of your network by providing a backup communication path if one subnet goes offline.

Disadvantages of Subnetting

There are a few potential drawbacks to using subnetting in a computer network:

• Complexity: Subnetting can add complexity to a network, as it requires the use of subnet masks and network addresses, which may be difficult for some users to understand.
• Additional hardware: In some cases, subnetting may require the use of additional hardware or network devices, such as routers or switches. Thus, increasing the cost of the network.
• Increased configuration: Subnetting requires the configuration of subnet masks and network addresses, which can be time-consuming and may require the assistance of a network administrator.
• Limited scalability: While subnetting can allow you to add more devices to a network without requiring additional IP addresses, it limits the number of subnets and devices that can be created.
• Security risks: Subnetting can improve security by creating separate networks for different users or devices, but it can also create security risks if not configured properly, as it can allow unauthorized users to access restricted resources.

Overall, the benefits of subnetting can outweigh the drawbacks. But it is essential to carefully consider the needs of your network and the potential impacts of subnetting before implementing it.

What is Subnet Calculator?

A subnet calculator (subnetting calculator) is a tool that helps a network administrator determine the various subnet parameters for a given IP address range. Using a subnet calculator, a network administrator can perform various tasks, such as:

• Determining the subnet mask to use.
• Identifying the broadcast address for a subnet.
• Calculating the range of IP addresses in a subnet.

Subnet calculators can be useful for planning and organizing large networks. These calculators helps in ensuring that IP addresses are assigned efficiently and without overlap.

Conclusion

This article has discussed subnetting in great detail, along with its example, working, characteristics, advantages, and so on. If you have any queries related to the topic, please feel free to send your query to us through a comment. We will be happy to help.

Happy learning!!