What action takes place when the source MAC address of a frame entering a switch is not in the MAC address table?
- The switch replaces the old entry and uses the more current port.
- The switch adds a MAC address table entry for the destination MAC address and the egress port.
- The switch updates the refresh timer for the entry.
- The switch adds the MAC address and incoming port number to the table.
| Explanation & Hint:
When a switch receives a frame and the source MAC address of that frame is not in the MAC address table, the switch will: The switch adds the MAC address and incoming port number to the table. This is how a switch learns the locations of devices within the network. Each time a frame is received, the switch records the source MAC address and the port on which the frame arrived. If a frame arrives with a destination MAC address that is not known, the switch will broadcast the frame out of all ports except the one on which it was received. However, it does not add the destination MAC address to the table until it receives a frame originating from that MAC address. |