Subnetting in Networking: Explained with Examples

I have been employed as a network designer for the last fifteen years. I have collaborated with several global organizations over the years, and all of these firms had one consistent demand- having an effective and rapid networking chain. And this is where my knowledge of subnetting made this work easier!

If you are a fresher or just starting to work in this field, believe me when I say that a deep understanding of subnetting in computer networks will take you a long way.

What is Subnetting?

Subnetting is a computer networking technology that divides a vast network into reduced more manageable smaller networks, or subnets. The basic purpose of subnetting is to facilitate the effective use of IP addresses and the management of network traffic

IPv4 addresses are commonly encoded as four octets, each spanning from 0 to 255 (e.g., 192.168.1.1). Subnetting is the process of stealing bits from the host component of an IP address and assigning them to the networking portion. This results in several lesser addresses inside the initially constructed system.

What is an IP address?

To completely appreciate subnets, we must first understand IP addresses. You must remember that both IP addressing and subnetting in computer networks are interdependent. Each device linked to the Internet is allocated a distinctive IP (Internet Protocol) address, allowing data communicated over the internet to be directed to the appropriate device among the vast number of devices linked to the internet at large. While systems recognize Internet Protocol (IP) addresses as an array of binary integers (1s and 0s), they are most typically expressed as a string of numeric characters.

Benefits of Subnetting

Subnetting has the following benefits:

1. Efficient Address Allocation: It makes optimum use of IP addresses by dividing an extensive address field into more compact ones, reducing waste.

2. Improved Network Productivity: By restricting domain broadcasting, smaller subnets tend to reduce traffic on the network while also boosting the general efficiency of the network.
3. Enhanced Security: Subnets may be employed to organize devices depending on performance or safety requirements, enabling more precise management of network communications and accessibility.

4. Simplified Network Administration: Dividing a vast network into multiple subnets may render network-related activities like debugging and tracking data easier.

Subnetting provides for more effective use of IP addresses as well as improved control and structuring of network resources. It is a critical component of IP networking, especially in systems of great size.

How Subnetting Works?

Subnetting divides a big IP network into fewer, simpler-to-manage networks, or subnets. This method involves obtaining bits from the server component of the IP address and assigning them to the computer network section. Here's an in-depth rundown of how subnetting works:

1. Identify the Network Address: First things first, begin with an IPv4 address, which you will find is represented by dotted decimal notations (e.g., 192.0.2.146). Determine the network component of the address using the subnet mask.
2. Select the Subnet Mask: The subnet mask is used to identify how many bits are assigned for the network component and the number of bits left for the host component. Popular subnet masks are/ 24 (255.255.255.0), /16 (255.255.0.0), and /8 (255.0.0.0).
3. Assess the Number of Subnets: Identify the number of subnets that are required to be formulated within the broader network. Doing this will help you determine the number of bits required to be borrowed from the host component.
4. Evaluate the Number of Hosts per Subnet: Estimate how many hosts are necessary in each subnet. This will assist in identifying what number of bits remain for the host portion after subnetting.
5. Evaluate the New Subnet Mask: Determine the new subnet mask based on the number of subnets and hosts per subnet.
6. Locate Subnet Addresses: Compute the subnet addresses for every subnet by increasing the network component of the IP address based on the updated subnet mask.
7. Allocate Host Addresses: Once subnets have been formed, allocate host addresses to each subnet. The host address is calculated by increasing the host part within the subnet address.
8. Apply Routing and Configuration: Set up routers and internet devices to detect subnetted IP addresses and redirect data appropriately. Verify that every gadget in every subnet is set to utilize the correct network mask.

Advantages of Subnetting

There are a lot of advantages of subnetting. Here are some essential ones:

• Subnetting can be utilized to reduce the number of IP (Internet Protocol) addresses.
• Subnets assist in preventing computers or electronics from dominating the entire network as well as allowing hosts to choose which types of users have permission to access critical information. Simply put, the subnetting notion allows us to determine whether or not a network is secure.
• The subnetting approach improves overall network efficiency by removing repetitive traffic that causes mistakes.
• We may use the previously stated idea of subnetting to divide an extensive network into individual networks.

Disadvantages of Subnetting

Though there are a lot of advantages of Subnetting, it also comes with a few disadvantages:

• If the quantity of subnets rises, so does the amount of routers. This occurs because every single subnet has a unique subnet mask, broadcast address, and network domain.
• Subnetting raises the overall connection cost since it necessitates the purchase of expensive internal switches, routers, platforms, and gateways.
• Subnetting increases the system's functionality. A professional network manager is required to oversee the subnetwork.

Examples

Now that I have shared the basics of subnetting with you, let me make the concepts easier for you with two subnetting in computer networks examples:

Example 1: Home Network

Situation: Assume you have several devices, such as PCs, cellphones, and smart televisions, all connected to the same network. You intend to subnet the network to boost its performance and safety.

Solution:

• Network Address: 192.168.0.0/24
• Subnetting Scheme:
• Subnet 1: Laptops (30 devices)Subnet Range: 192.168.0.0/27 (30 addresses)IP Range: 192.168.0.1- 192.168.0.30
• Subnet 2: Smartphones (20 devices)Subnet Range: 192.168.0.32/27 (30 addresses)IP Range: 192.168.0.33- 192.168.0.62
• Subnet 3: Smart Televisions (10 devices)Subnet Range: 192.168.0.64/28 (14 devices)IP Range: 192.168.0.65- 192.168.0.78

By using this subnetting technique, you will be able to easily divide your home network into numerous subnets based on your equipment. By shifting traffic, the system's security, speed, and connection will all increase.

Example 2: Small Business Network

Situation: You own a small-scale business. Your company has several divisions, including sales, marketing, accounting, and information technology. You want to allocate subnets to each unit to boost efficiency and security.

Solution:

• Network Address: 10.0.0.0/22
• Subnetting Scheme:
• Subnet 1: Sales (80 employees)Subnet Range: 10.0.0.0/25 (126 addresses)IP Range: 10.0.0.1- 10.0.0.126
• Subnet 2: Marketing (30 employees)Subnet Range: 10.0.0.128/26 (62 addresses)IP Range: 10.0.0.129- 10.0.0.190
• Subnet 3: Accounting (15 employees)Subnet Range: 10.0.0.192/27 (30 addresses)IP Range: 10.0.0.193- 10.0.0.222
• Subnet 4: IT (8 employees)Subnet Range: 10.0.0.224/28 (14 addresses)IP Range: 10.0.0.225- 10.0.0.238

This subnetting technique will enable you to quickly distribute IP addresses throughout each division while maintaining segregation and privacy between them.

Summing up

Summing up, subnetting is a key technique in computer networking that enables effective use of IP addresses and improved control of network facilities. Subnetting breaks a network into more compact, distinct networks, enabling better routing, increased safety through sorting, and simpler debugging and maintenance. While subnetting in computer networks may appear difficult at first, understanding this ability is critical for anybody dealing with networked devices. Professionals who regularly practice and understand subnetting ideas may securely create and manage networks that satisfy the changing demands of modern technology.

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