What Is a Subnet Mask?

What is a Subnet Mask? A Glimpse on Network Security

Essence of Subnet Masks


what is subnet mask?


Also known as net masks, a subnet mask is utilized to create concrete notions of the number of bits that a particular network should use to designate IP addresses.

Furthermore, it also functions as some sort of an IP address that could point out the size of a smaller network to which other network components and devices are connected to.

One of its main functions is to divide an IP address into two elements. These two important components are the network address and the host address.

This means that subnetting would split a certain host section into its own structure which could be formed like this:


Through easier and smoother transactions,  employing subnet masks would enhance security and safety as it can also block other computers or subnetworks from access. Because of these very essential benefits, and also the stability that a subnet mask offers, subnetting has become a staple commodity in the network infrastructure, and has since expanded its array and reach.

Variations of Subnet Masks

There are a number of network classes on which a subnet mask can be utilized and integrated. These are the following: Class A (16-bit), Class B (16-bit), and Class C (24-bit). These networks have their own
varieties of subnet masks and can be categorized as shown below:

  • The subnet mask of is often used by Class A (16-bit) networks and can provide support for almost 16,777,216 other hosts.
  • The subnet mask of is often used by Class B (16-bit) networks and can provide support for only 65,534 IP devices.
  • The subnet mask of is often used by Class C (24-bit) networks and can provide 256 IP devices. The Class C category is where most home networks reside, and can also be recommended for smaller companies and businesses.

A concrete example would be to look at an IP address that has the numbers Taking into consideration that it is a Class B category network, the first two numbers in the address would be the network address, and the last two numbers would describe the host address.

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