At which OSI layer do switches primarily operate?

Switches primarily operate at Layer 2 of the OSI model, which is the Data Link layer. This layer is responsible for the node-to-node data transfer and handles the physical addressing of frames. Switches use MAC addresses to make forwarding decisions and filter traffic, effectively creating a separate collision domain for each connected device. This characteristic enhances the efficiency of a network's performance by reducing unnecessary traffic.

While switches can technically operate at Layer 1 by forwarding signals, their main functionality revolves around frame processing at Layer 2. Additionally, Layer 3 devices, such as routers, focus on packet forwarding based on IP addresses, which is a distinct function compared to the fundamental role of switches at Layer 2. Layer 4 deals with transport-related functions like flow control and error correction, which are not part of what traditional switches do. Therefore, the Data Link layer is where switches primarily contribute to network operations.