100-150 Question 191
Single answerA network administrator notices that unauthorized devices are connecting to the network in a specific VLAN. To mitigate this issue, they decide to implement MAC address filtering on the switch. During configuration, what will the switch do if a device with an unrecognized MAC address attempts to connect to this VLAN?
- A
Allow the device to connect but assign it to a default VLAN
- B
Deny the connection and block the MAC address from the network
- C
Drop all frames from the unrecognized MAC address
- D
Forward the frames to the default gateway for further inspection
Show answer and explanation
Correct answer: C
Explanation
MAC address filtering allows administrators to control which devices can connect to the network by permitting or denying traffic based on MAC addresses. When an unrecognized MAC address attempts to connect, the switch enforces the filtering policy by dropping all frames from the unauthorized MAC address, preventing it from accessing the network.
- A. Incorrect.
This is incorrect because MAC address filtering does not assign devices to a default VLAN upon failure. It simply enforces whether a MAC address is allowed or denied.
- B. Incorrect.
This is partially incorrect. While the connection is denied, the MAC address is not necessarily blocked dynamically; filtering simply drops frames from unrecognized MAC addresses.
- C. Correct.
This is correct. When MAC address filtering is enabled, the switch drops all frames from unrecognized or unauthorized MAC addresses.
- D. Incorrect.
This is incorrect because the switch does not forward frames to the default gateway for inspection. The switch enforces MAC filtering locally.