What is the function of a subnet mask in networking?

The function of a subnet mask in networking is to determine an IP address's subnet. A subnet mask works in conjunction with an IP address to segment a network into smaller, more manageable parts known as subnets. It defines which portion of the IP address represents the network and which part refers to the individual host within that network. By using a subnet mask, devices and routers can effectively route traffic within and between subnets, ensuring that data is sent to the correct destination in a networked environment.

This understanding is essential for efficient network management and helps in optimizing network performance by reducing broadcast domains and improving security. When configuring networks or troubleshooting connectivity issues, recognizing the role of the subnet mask is fundamental for IT professionals.