When a frame is sent from PCA and the MAC address table on switch SW1 is empty, SW1 will flood the frame out on all ports except the port through which the frame entered. This means SW1 does not yet know the destination MAC address location, so it broadcasts (floods) the frame to all other ports to find the destination device. This behavior helps SW1 learn the MAC addresses dynamically as devices respond, building its MAC address table for future frame forwarding. In summary:
- SW1 floods the frame on all ports except the incoming port because its MAC address table is empty.
- This flooding allows SW1 to discover the destination MAC address connected port when the responding device replies, enabling proper forwarding in the future.
This explanation aligns with standard switch behavior when the MAC address table is empty or does not have an entry for the destination MAC address.
