What is the table on a switch mapping MAC addresses to the switch ports where those devices are connected?

What is the table on a switch mapping MAC addresses to the switch ports where those devices are connected?

• A. Routing Table
• B. MAC Address Table
• C. ARP Cache
• D. VLAN Table

Answer: (B)

Switches learn where devices live by building a MAC address table that records which MAC addresses are reachable on which switch ports. When a frame arrives, the switch notes the frame’s source MAC address and the port it came in on, updating this table. Later, it uses the table to forward frames only to the port associated with the destination MAC, flooding only if the destination is unknown. This per‑port, per‑MAC mapping is the essence of the switch’s MAC address table (often called a CAM table). This is different from a routing table, which stores network destinations and next hops for layer 3 routing; the ARP cache on a host (or router) maps IP addresses to MAC addresses for local delivery, not per-switch port mappings; and a VLAN table defines which ports belong to which VLAN, not the address-to-port mappings used for frame forwarding.

Switches learn where devices live by building a MAC address table that records which MAC addresses are reachable on which switch ports. When a frame arrives, the switch notes the frame’s source MAC address and the port it came in on, updating this table. Later, it uses the table to forward frames only to the port associated with the destination MAC, flooding only if the destination is unknown. This per‑port, per‑MAC mapping is the essence of the switch’s MAC address table (often called a CAM table).

This is different from a routing table, which stores network destinations and next hops for layer 3 routing; the ARP cache on a host (or router) maps IP addresses to MAC addresses for local delivery, not per-switch port mappings; and a VLAN table defines which ports belong to which VLAN, not the address-to-port mappings used for frame forwarding.