Difference between Subnetting and Supernetting

Introduction

A network is a collection of two or more computers that can communicate with one another to share data and resources. A device within a network is identified uniquely through the use of IP addresses. Subnetting and Supernetting are two methods used to organize IP addresses. Subnetting is a method of breaking a huge network into smaller ones, whereas supernetting is a method of joining many networks into one.

In this blog, we will discuss the basic difference between the two, i.e., Subnetting and Supernetting. Let’s begin!

Difference between Subnetting and Supernetting

The basic difference between the two has been explained in the form of a table based on various factors.

We have explained the fundamental differences; now, let’s understand both subnetting and supernetting in detail.

What is Subnetting in Computer Networks?

Subnetting is a method used to divide a given physical network into smaller units known as sub-networks. Sub-networks are often referred to as subnets. An internal address is composed of a combination of the small networks segment and the host segment. A subnetwork is created by taking the bits from the host section of the IP address, which are then used to allocate a set of smaller sub-networks inside the original network.

How does Subnetting work?

During the process of subnetting, the network bits undergo conversion into host bits. The subnetting method is used in order to reduce the rapid exhaustion of available IP addresses. The administrator can divide the singular class A, class B, and class C into smaller portions. Subnetting employs both Variable Length Subnet Mask (VLSM) and Fixed Length Subnet Mask (FLSM) techniques.

Dividing the IP address space into subnets of varying sizes is called Variable Length Subnet Mask (VLSM). VLSM is a technique that minimizes memory waste. Dividing the IP address space into a subnet of equal magnitude is referred to as a Fixed Length Subnet Mask.

Advantages of Subnetting

Some of the advantages associated with subnetting are:

• Subnetting offers numerous benefits in network routing within large network ecosystems.
• Subnetting allows the reduction of network traffic by decreasing the volume of broadcasts.
• Maintaining Subnets is simpler because of their manageable size, while the process of organizing them is further simplified through Subnetting.

Disadvantages of Subnetting

Some of the disadvantages associated with subnetting are:

• It can increase the risk of misconfiguration and human errors, as subnetting requires careful planning and calculation of subnet masks, addresses, and ranges.
• It can increase the cost of network equipment and maintenance as more routers, switches, and cables are needed.

We have explained subnetting in detail; now, let’s move on to Supernetting.

What is Supernetting in Computer Networks?

To create a larger network out of many smaller ones, a technique known as “supernetting” is used. It works by doing the opposite of what subnetting does.

How does Supernetting work?

Supernetting shifts the mask bits to the left of the normal mask, turning the network bits into the host bits. Supernetting is also known as router aggregation or router summarization. At the price of network addresses, it generates a larger number of host addresses. The supernetting technique is carried out by the ISP in order to allocate IP addresses in the most effective manner.

The CIDR (Classless Inter-Domain Routing) protocol directs network traffic across the internet. CIDR is used to route network traffic across several subnetworks at once. Simply said, CIDR is a way to group IP addresses into subnetworks independent of the address’s value.

Advantages of Supernetting

Below we have outlined some of the advantages of supernetting. These are:

• The router memory table is optimized by combining multiple routing information entries into a single entry, thereby reducing its size.
• Additionally, it enhances the efficiency of the routing table lookup process by increasing its speed.
• The router should be equipped with a provision to isolate topology changes from other routers effectively.
• Additionally, it has the capability to decrease network traffic.

Disadvantages of Supernetting

Some of the disadvantages of supernetting are:

• It can create security risks if the supernetted network spans across different administrative domains or trust levels.
• It can increase the complexity of routing and subnetting calculations.
• The whole network must be in the same class.

Subnetting vs Supernetting

Below we have explained the difference between subnetting and supernetting in detail. The difference between them can be summarized based on the following factors:

Definition

Subnetting is the process of splitting a network into smaller subnetworks, each with its own range of IP addresses and subnet masks.

Supernetting is the opposite process of combining multiple subnetworks into a larger one with a common IP address and subnet mask.

Purpose

Subnetting reduces network congestion, improves security, and simplifies network management.

Supernetting is used to reduce the size of routing tables, optimize routing performance, and conserve IP address space.

Bits

Subnetting involves borrowing bits from the host portion of an IP address and adding them to the network portion, creating more subnetworks with fewer hosts each.

Supernetting involves borrowing bits from the network portion of an IP address and adding them to the host portion, creating fewer subnetworks with more hosts each.

Mask

Subnetting uses a subnet mask that has more 1s than the default network mask, indicating a smaller subnetwork.

Supernetting uses a supernet mask that has fewer 1s than the default network mask, indicating a larger subnetwork.

Implementation

Subnetting is implemented by network administrators using VLSM and FLSM.

Supernetting is implemented by Internet service providers (ISPs) using classless inter-domain routing (CIDR).

These are the top difference between Subnetting and Supernetting.

Frequently Asked Questions

Q1 – What is the difference between subnetting and supernetting?

Subnetting is the process by which a large network is divided into sub-networks. Whereas, Supernetting is the process by which small networks are combined to form a large network.

Q2 – What is the difference between a subnet and a subnetting?

A subnet is a logical division of an IP network into smaller segments that share a common prefix. Subnetting is the process of creating subnets by assigning bits from the host portion of an IP address to the network portion.

Q3 – What are the 2 types of subnets?

Two types of subnets are FLSM and VLSM. In FLSM, each subnet uses the same Subnet mask and has the same amount of host addresses. With VLSM, the number of hosts per subnet and the subnet mask may vary.

Q4 – Why is supernetting used?

Supernetting is a technique that allows multiple networks to be combined into a larger network and is used to reduce the number of routing entries and simplify network management.

Conclusion

In this blog, we have discussed two crucial processes, i.e., Subnetting and Supernetting. We also have seen their advantages and disadvantages. Both techniques are used to extend the number of usable IP addresses and prevent depletion. We also have discussed the basic difference between subnetting and supernetting.