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(also subnet mask)

Netmask definition

A netmask is a 32-bit binary mask that divides an IP address into subnets or smaller networks and defines networking rules in routers and firewalls. It is also used to determine the class and range of IP addresses, which makes computer networking easier. A netmask provides the number range of IP addresses from Class A to Class C and sets a mask that divides them into subnets.

Additionally, dividing IP addresses into subnets depends on the IP address class, and the longer the netmask is, the more networks it can house. In a netmask, two possible addresses representing the final byte are always automatically assigned. For instance, in, the “0” is the given network address, while in, the last “255” is the given broadcast address. As a result, these two values can’t be used to assign IP addresses.

See also: IPv4, class A IP address

Benefits of a netmask

  • Improves network speed and performance because it divides broadcast domains, meaning that traffic routing is more efficient.
  • Reduces significant traffic congestion and the load on the network because it ensures that traffic remains in its appointed subnet.
  • Decreases the distance that data packets need to travel, which improves network performance.
  • Provides advanced network security because companies can determine which hardware and users can access more sensitive data.
  • Allows organizations to have complete control over their traffic, data packets, routers, and network, which increases efficiency.

Further reading

Ultimate digital security