200-301 Question 158
Select 3A network administrator notices unusual traffic on a switch where frames are being sent to multiple ports unnecessarily. Upon investigation, it is determined that the switch is performing frame flooding. In which of the following scenarios would frame flooding occur?
- A
The switch receives a frame with an unknown destination MAC address.
- B
The MAC address table of the switch is full and cannot learn new addresses.
- C
The switch is configured in cut-through mode rather than store-and-forward mode.
- D
A broadcast frame is sent into the switch.
- E
The switch's VLAN configuration is misconfigured, causing frames to be forwarded to all VLANs.
Show answer and explanation
Correct answers: A, B, D
Explanation
Frame flooding occurs in scenarios where a switch is unable to determine the correct port to forward a frame. Common causes include an unknown destination MAC address, a full MAC address table, or broadcast traffic. These scenarios ensure the frame reaches its intended destination or all devices in the broadcast domain. However, switching modes or VLAN misconfigurations are unrelated to frame flooding.
- A. Correct.
Correct. If the switch receives a frame with an unknown destination MAC address, it floods the frame out all ports except the one it was received on to ensure it reaches the destination.
- B. Correct.
Correct. If the MAC address table is full, the switch cannot learn new addresses, so it floods frames destined for unknown MAC addresses.
- C. Incorrect.
Incorrect. The switching mode (cut-through or store-and-forward) does not directly cause frame flooding. This is unrelated to the MAC address table or flooding behavior.
- D. Correct.
Correct. Broadcast frames are inherently designed to be sent to all devices in the broadcast domain, which causes frame flooding.
- E. Incorrect.
Incorrect. A VLAN misconfiguration may cause other issues, but it is not a direct cause of frame flooding. Frame flooding is tied to MAC address learning and broadcast traffic.