Understanding Subnet Mask in Computer Networks

A subnet mask is a 32-bit numerical value that is used in conjunction with an IP address to differentiate the network portion and host portion of the address. It helps in dividing a larger network into smaller subnetworks, known as subnets.

When a device needs to communicate with another device within the same network, it uses the subnet mask to determine whether the destination IP address is within the same subnet or a different subnet. If the destination IP address is in the same subnet, the device can directly communicate with it without involving a router. If the destination IP address is in a different subnet, the device sends the data to the router.

Subnet masks are represented in the form of four octets, each containing eight bits (e.g., 255.255.255.0). The subnet mask is applied to the IP address using a bitwise AND operation to determine the network address and host address. The result helps in routing packets within the network efficiently.

Overall, understanding subnet masks is crucial in designing and managing computer networks to optimize performance and manage network traffic effectively.