Which device forwards frames based on MAC addresses at the data link layer?

Which device forwards frames based on MAC addresses at the data link layer?

• A. Hub
• B. Switch
• C. Router
• D. Bridge

Answer: (B)

This question focuses on how devices at the data link layer forward frames using MAC addresses. A switch does this by building a MAC address table from the source addresses it sees on incoming frames. When a frame arrives, the switch checks the destination MAC and forwards the frame only to the port associated with that MAC. If the destination isn’t in the table yet, the switch floods the frame to all ports except the source, and as responses come back, it learns where each MAC is located. That’s why a switch is the correct choice: it actively uses MAC addresses to direct traffic and maintains per-port separation, unlike a hub which just repeats signals (layer 1), or a router which uses IP addresses (layer 3). A bridge also operates at the data link layer, but switches are the standard, scalable device for MAC-based forwarding.

This question focuses on how devices at the data link layer forward frames using MAC addresses. A switch does this by building a MAC address table from the source addresses it sees on incoming frames. When a frame arrives, the switch checks the destination MAC and forwards the frame only to the port associated with that MAC. If the destination isn’t in the table yet, the switch floods the frame to all ports except the source, and as responses come back, it learns where each MAC is located.

That’s why a switch is the correct choice: it actively uses MAC addresses to direct traffic and maintains per-port separation, unlike a hub which just repeats signals (layer 1), or a router which uses IP addresses (layer 3). A bridge also operates at the data link layer, but switches are the standard, scalable device for MAC-based forwarding.