ITPEC FE Subject A April 2024 Question 23
Which of the following is the network device that makes a forwarding decision on the basis of the destination MAC address in the frame header?
Explanation
Switching hub — a Layer 2 device that forwards each frame by its destination MAC address.
A switching hub (Layer 2 switch) learns which MAC address sits behind which port by reading the source address of incoming frames. When a frame arrives, it looks up the destination MAC address in that table and sends the frame out of the matching port only, instead of to every port.
Answer (d)
Why not others:
- •(a) Patch cable — a passive cable that carries the signal; it makes no decisions at all
- •(b) Repeater hub — a Layer 1 device that regenerates the signal and sends it out of every port without reading any address
- •(c) Router — a Layer 3 device that forwards packets by destination IP address, not MAC address
Key rule: Match the device to the address it reads: none (Layer 1) is a repeater or repeater hub, MAC address (Layer 2) is a switch or bridge, IP address (Layer 3) is a router.
Networks · AI-written, may contain errors
This question comes from an official ITPEC past paper. ITPEC Practice is an independent study tool and is not affiliated with ITPEC. See the official FE past-paper collection or Report an issue.