What is the primary purpose of a subnet mask in networking?

A subnet mask plays a crucial role in networking by defining the network portion of an IP address, which is essential for proper routing and addressing. In an IP address, there are generally two main parts: the network part, which identifies the specific network segment, and the host part, which identifies a specific device within that network. The subnet mask facilitates the differentiation between these two components by specifying how many bits of the IP address are used for the network and how many are reserved for hosts.

For instance, in a common subnet mask of 255.255.255.0, the first three octets (255.255.255) denote the network part, while the last octet (0) indicates the host part. This means that any IP address with the same first three octets belongs to the same subnet, allowing devices within that range to communicate directly without needing routing. Thus, the proper use of a subnet mask is fundamental for ensuring that data packets reach the correct destination within a network, enhancing the overall organization and efficiency of IP address management.

The other options, while relevant to various functions within networking, do not accurately describe the primary purpose of a subnet mask. Encrypting data packets involves security measures rather than network addressing. Managing traffic between