How does a switch use the MAC address table to forward unicast frames?

• A. It uses the table to forward frames to the next hop router.
• B. It uses the table to drop frames destined to unknown MACs.
• C. It uses the table to assign MAC addresses to ports.
• D. It uses the table to forward unicast frames to the specific port associated with the destination MAC.

Answer: (D)

Switches forward unicast frames by using the MAC address table (CAM table). The switch learns which MAC addresses are reachable on which ports by inspecting the source MAC of every frame it receives, building a mapping of MAC address to ingress port. When a unicast frame arrives, it looks up the destination MAC in that table. If there’s a match, the switch sends the frame only out the port associated with that destination, delivering it directly to the intended device and avoiding unnecessary traffic on other ports. If the destination MAC isn’t in the table, the switch floods the frame to all ports in the same VLAN so the destination device can respond and the mapping can be learned. This behavior is specific to Layer 2 switching and is separate from routing at Layer 3, which uses IP addresses. The switch isn’t assigning MACs to ports; it learns the existing addresses on each port.