200-301 Question 157
Single answerYou are troubleshooting a switch in a network where a specific frame is being sent to all switch ports, even though the destination MAC address is known to exist in the network. Which of the following scenarios is most likely causing this behavior?
- A
The MAC address table on the switch has aged out the destination MAC address.
- B
The frame has an incorrect VLAN tag configured.
- C
The source MAC address is not present in the MAC address table.
- D
The destination MAC address is a broadcast address.
Show answer and explanation
Correct answer: A
Explanation
Frame flooding occurs when a switch does not have an entry for the destination MAC address in its MAC address table. In this scenario, if the MAC address table has aged out the destination MAC address, the switch will flood the frame to all ports within the same VLAN to ensure the frame reaches its intended destination. This behavior is part of normal switch operation to handle unknown or aged-out MAC addresses.
- A. Correct.
If the MAC address table has aged out the destination MAC address, the switch will flood the frame to all ports within the same VLAN, as it does not know the specific port associated with the destination MAC address.
- B. Incorrect.
While an incorrect VLAN tag may cause communication issues, it does not lead to frame flooding across ports. Instead, the frame would likely be dropped or misrouted.
- C. Incorrect.
The absence of the source MAC address in the MAC address table would cause the switch to add it to the table but does not affect how the destination frame is handled.
- D. Incorrect.
A broadcast address causes intended flooding, but the question specifies that the destination MAC address is known to exist in the network, so this option is not applicable.