Which layer of the OSI model does a switch operate at?

A switch primarily operates at Layer 2, also known as the Data Link layer, of the OSI model. This layer is responsible for node-to-node data transfer and error detection and correction in the data frames that are sent between devices on a network.

At this layer, switches use MAC (Media Access Control) addresses to forward data frames to the appropriate destination within a local area network (LAN). By using these addresses, switches can create a MAC address table which helps them to efficiently direct incoming data to the correct output port without flooding all connected devices with the traffic. This enhances network performance and reduces unnecessary data collisions.

While some advanced switches, known as Layer 3 switches, can perform routing functions (operating at Layer 3), the fundamental operation of standard switches is focused at the Data Link layer. Thus, identifying the correct layer where switches primarily operate is crucial for understanding networking technologies and how data flows through switched networks.