Learn how a switch handles frames with unknown destination MAC addresses for the CCNA 200-301 exam. Understand why switches flood these frames to all ports except the source to ensure delivery.
Table of Contents
Question
A switch receives a frame with a destination MAC address that is not in its MAC table. What will the switch do?
A. Drop the frame
B. Forward it to the default gateway
C. Send an ICMP request
D. Flood the frame out all ports except the source port
E. Generate an ARP request
Answer
D. Flood the frame out all ports except the source port
Explanation
If the switch does not have the MAC address in its table, it floods the frame to all ports except the one it was received on.
When a switch receives a frame with a destination MAC address that is not in its MAC address table, it floods the frame out all ports except the one on which it was received. This process, known as unknown unicast flooding, ensures the frame reaches its intended recipient even if the switch does not yet know which port corresponds to the destination MAC address. Once the destination device responds, the switch learns its MAC address and updates the MAC table for future forwarding decisions.
Cisco Certified Network Associate CCNA 200-301 certification exam practice question and answer (Q&A) dump with detail explanation and reference available free, helpful to pass the Cisco Certified Network Associate CCNA 200-301 exam and earn Cisco Certified Network Associate CCNA 200-301 certification.