What is the purpose of a subnet mask?

The purpose of a subnet mask is to divide an IP address into network and host components. In networking, IP addresses are used to identify devices on a network, and each IP address consists of two parts: the network portion, which identifies the specific network, and the host portion, which identifies the specific device on that network.

The subnet mask acts as a filter that helps define which part of an IP address represents the network and which part represents the host. By using a specific subnet mask, network administrators can effectively segment the network into smaller, manageable sub-networks, or subnets. This segmentation is crucial for efficient IP address management and helps to prevent IP conflicts among devices.

While enhancing network security, increasing bandwidth capacity, and simplifying routing tables are important aspects of networking, they are not the primary function of the subnet mask itself. The direct role of a subnet mask is focused on how an IP address is structured and interpreted.