What is a Subnet?

Any group of computers using Internet Protocol (IP) as its network layer communications protocol can be referred to as a network. Any portion of that network where the computers share a continuous range of IP addresses that are a smaller set of a larger network are a sub-network or subnet.

The term subnet came into use because there are a finite number of IP addresses and too many of them were given out too quickly in the early days of the Internet. The need to become more efficient about how IP addresses are used required carving up the blocks of classful addresses into smaller ranges of addresses.

 

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