Which type of address does a switch use to build the MAC address table?

A switch uses the source MAC address to build its MAC address table, which is crucial for efficient data packet forwarding within a network. When a switch receives a frame, it examines the source MAC address of the incoming frame and learns which port that address is associated with. This process allows the switch to maintain a table (commonly referred to as the MAC address table) that maps MAC addresses to specific switch ports. By doing so, when the switch receives a frame destined for a particular MAC address, it can refer to its MAC address table and forward the frame only to the appropriate port, thereby reducing unnecessary traffic and enhancing overall network performance.

The other types of addresses mentioned are used differently in networking. The destination MAC address is relevant for determining where the frame is intended to go, but it does not help in building the table – the switch simply forwards frames to the destination based on the table built from the source addresses. The broadcast MAC address is utilized when a frame is sent to all devices on a network, and this does not contribute to the learning process for the MAC address table. Lastly, an IP address pertains to the network layer and is not used by switches at the data link layer for building tables. Hence, the source MAC address is the key