Subnetting and Supernetting in Computer Network

In this tutorial, we will learn what is subnetting and supernetting related to classful addressing and what are the differences between Subnetting and Supernetting? By Radib Kar Last updated : May 04, 2023

What is Subnetting?

Subnetting is a concept of diving a block of addresses into sub-blocks of addresses. During the era of classful addressing (as it’s obscured now), subnetting was introduced. Say, an organization is granted a large block in class A or B, it can divide the address block assigned into several contiguous groups (sub-blocks) and assign each group to smaller networks (subnets).

What is Supernetting?

The biggest drawback of classful addressing is address depletion. The issue came in front when most of class A and class B addresses were depleted and there was still a huge demand for midsize blocks. Class C was too small to adjust and solve the situation as the size of a class C block with a maximum number of 256 addresses hardly satisfied the needs of most organizations.

Even a midsize organization needed more address range. The solution was supernetting.

In supernetting, an organization can combine several class C blocks to create a larger block of addresses. Several networks were combined to create a supernetwork. An organization can apply for a set of class C blocks (i.e. multiple class of C blocks) instead of just one. For example, an organization that needs 500 addresses can be granted three contiguous class C blocks. Then, an organization can use such addresses to create one supernetwork.

Classless addressing actually eliminated the need for supernetting.

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