Which of the following is NOT true with respect to a transparent bridge and a…

Concept. A bridge and a router operate at different layers of the protocol stack and key their forwarding on different kinds of addresses. A bridge is a Data Link (Layer 2) device: it forwards Ethernet frames within a LAN and keys its decisions on MAC addresses, which it learns automatically by observing the source address of incoming frames. A router is a Network (Layer 3) device: it forwards packets between separate networks and keys its decisions on IP addresses held in a routing table.

Applying this to the statements. The question asks for the one statement that is NOT true. Test each against the layer/address rule above:

• “Both bridge and router selectively forward data packets” — true; each consults its own table (MAC table for the bridge, routing table for the router) to forward or filter.

• “A bridge uses IP addresses while a router uses MAC addresses” — false; this swaps the layers. The bridge uses MAC addresses and the router uses IP addresses, not the reverse.

• “A bridge builds up its routing table by inspecting incoming packets” — true in mechanism; the bridge learns addresses from incoming frames. (The table is strictly a MAC/CAM forwarding table; “routing table” is loose wording, but the learning behaviour described is correct.)

• “A router can connect between a LAN and a WAN” — true; joining different networks is a core router function.

Cross-check. Only one statement contradicts the layer/address rule outright: the claim that a bridge uses IP and a router uses MAC. Every memory of “bridge = Layer 2 = MAC, router = Layer 3 = IP” flags it immediately. The remaining three describe correct behaviour, so they are all true and therefore not the answer.

Result. The statement that is NOT true is “A bridge uses IP addresses while a router uses MAC addresses.”