Question

Hosts A through J have been connected to a switch for some time, with Host A on port 1, Host B on port 2, and so on. A user moves his system and connects Host A to interface 12. Immediately after the connection, Host A sends a unicast message to Host B. Which of the following are true?

A. When the frame enters the switch, it is flooded to all interfaces.

B. When the frame enters the switch, it is sent directly to interface 2, and no other.

C. After this unicast message is sent, frames addressed to Host A will continue to be sent to interface 1.

D. After this unicast message is sent, frames addressed to Host A will be sent to interface 12.

Answer 1

B and D are correct. Moving Host A to a different port would not affect the delivery of frames with a destination MAC for Host B—still on port 2. As the first message from Host A is received, the CAM table will update to the new port (12).

A and C are incorrect. A is incorrect because only three types of frames are flooded by switches: broadcast, multicast, and frames without a matching entry in the CAM table. Since Host B is still in the CAM table, the message would be delivered appropriately. C is incorrect because the CAM table is updated to Host A’s new port number immediately after the frame enters the switch.