200-301 Question 156
Single answerA network administrator is troubleshooting an issue where frames are not reaching their intended destination. Upon reviewing the switch's MAC address table, they notice that the destination MAC address of the frame is not present in the table. What action will the switch take in this scenario?
- A
The switch will drop the frame immediately.
- B
The switch will forward the frame to all ports except the one it was received on.
- C
The switch will forward the frame only to the port where the source MAC address was learned.
- D
The switch will store the frame in memory until the destination MAC address is learned.
Show answer and explanation
Correct answer: B
Explanation
Frame switching involves the switch making decisions based on the MAC address table. If the destination MAC address is not present in the table, the switch cannot determine the specific port to forward the frame. To ensure the frame reaches its destination, the switch floods the frame out of all ports except the one it was received on. This behavior ensures connectivity in cases where the MAC address table is incomplete.
- A. Incorrect.
The switch does not drop the frame in this scenario; it uses a flooding mechanism when the destination MAC address is unknown.
- B. Correct.
Correct. When the MAC address table does not have an entry for the destination MAC, the switch floods the frame out all ports except the one it was received on.
- C. Incorrect.
The switch does not forward the frame only to the source MAC address's corresponding port; it needs to ensure the frame reaches the correct destination, so it floods the frame in this case.
- D. Incorrect.
The switch does not store the frame in memory for later forwarding. Instead, it uses flooding to ensure the frame reaches the correct destination.