The four numbers are then arranged as contiguous maximum values followed by contiguous minimum values.

In the class-based method, each of these four numbers can only have a maximum value of 255 or a minimum value of 0. A subnet mask, like an IP address, is made up of four numbers. To split a network identifier, use a subnet mask.Ī subnet mask distinguishes the network identifier from the host identifier in an IP address, but is not restricted by the same rules as the class-based method. Using these smaller network identifiers, the network can be divided into subnets, each with its own network identifier, also known as a subnet identifier. With subnetting, a class-based network identifier can be divided into smaller (according to the defined number of identified IP addresses) network identifiers. To solve this problem, the concept of subnetting was introduced.

If there are a large number of hosts, the network will not perform efficiently. With a single network identifier, the organization can have only a single network that connects the assigned number of hosts. Therefore, an organization assigned a network identifier has a single fixed network identifier and a specified number of hosts determined by the address class to which the IP address belongs. With the class-based method, the number of networks and hosts available for a particular address class is determined in advance.

Another term for subnet mask