CCNA: Cisco Certified Network Associate — Question 982

An Ethernet frame arrived at switch interface G0/1, but the destination MAC address is missing from the MAC address table. How does the switch process the frame?

Answer options

• A. It sends an ARP request to attempt to locate the destination
• B. It updates the destination to FFFF.FFFF.FFFF.
• C. It drops the frame and notifies the sending host.
• D. It floods the frame out of the remaining switch interfaces.

Correct answer: D

Explanation

The correct answer is D because when a switch does not find the destination MAC address in its table, it floods the frame to all other interfaces to locate the destination device. Option A is incorrect because ARP is used for IP address resolution, not for MAC address flooding. Option B is not applicable, as switches do not update unknown destination addresses to the broadcast address, and option C is incorrect because drops do not involve notifying the sender.