What is a switch's forwarding table?

A switch's forwarding table, often referred to as a MAC address table, plays a crucial role in the operation of network switches. This data structure is fundamental to how switches function in efficiently directing traffic within a local area network (LAN). Specifically, the forwarding table maps each MAC (Media Access Control) address to the corresponding port on the switch, allowing the switch to make informed packet forwarding decisions.

When a switch receives a frame, it checks the source MAC address and binds that address to the port from which the frame was received. This information is stored in the forwarding table. When the switch needs to forward a frame, it references the table to determine which port to use based on the destination MAC address. If the destination MAC address is found in the forwarding table, the switch sends the frame directly to the corresponding port. If the address is not found, the switch will flood the frame to all ports except the one it originated from, in an attempt to locate the destination device.

This efficient mapping and forwarding process help minimize unnecessary network traffic and speed up overall data transmission between devices connected to the switch, showcasing the significance of the forwarding table in networking environments.