What action takes place when a frame entering a switch has a unicast destination MAC address that is not in the MAC address table?
- The switch resets the refresh timer on all MAC address table entries.
- The switch updates the refresh timer for the entry.
- The switch replaces the old entry and uses the more current port.
- The switch will forward the frame out all ports except the incoming port.
| Explanation & Hint:
When a frame entering a switch has a unicast destination MAC address that is not in the MAC address table, the switch will: The switch will forward the frame out all ports except the incoming port. This behavior is known as “flooding.” The switch does this because it does not have any information on which port the destination device is located. By flooding the frame to all ports (except the one it received the frame on), the switch ensures that the frame reaches its intended destination. Once the destination device responds and the switch receives a frame with the source MAC address of that device, the switch will then add the MAC address and corresponding port to the MAC address table for future reference. |