What device operates at the network layer of the OSI model?

The device that operates at the network layer of the OSI model is a router. The network layer is responsible for packet forwarding including routing through intermediate routers. Routers use IP addresses to determine the best path for data packets to travel across different networks, making decisions based on the logical addressing information contained in the packets.

Routers analyze network traffic and can manage and direct packets between separate networks. They also facilitate connections between local area networks (LANs) and wide area networks (WANs). This function distinguishes routers from other network devices, which primarily operate at lower layers of the OSI model. For instance, switches operate at the data link layer and function mainly to switch packets within the same local area network without making routing decisions. Hubs operate at the physical layer, simply relaying data without any intelligence regarding the path the data should take. Bridges, similar to switches, operate at the data link layer but are primarily used to connect and filter traffic between two networks.

Understanding the roles of different devices in the OSI model is key to configuring and troubleshooting networks effectively.