What is the default aging timer for a MAC Address table in a Cisco switch?

The default aging timer for a MAC address table in a Cisco switch is indeed set to 300 seconds. This timer determines how long a MAC address entry remains in the switch's MAC address table if there are no additional frames sent from that address. After this period, if the MAC address hasn't been seen again, it is removed from the table to free up space for new entries.

This aging process helps manage the size of the MAC address table and optimize memory usage on the switch. If the switch is receiving a steady stream of traffic from a device, the corresponding MAC address entry will be refreshed, effectively resetting the timer, thereby keeping the entry valid as long as there’s ongoing communication.

Understanding this concept is crucial for network configurations and troubleshooting related to MAC address table management, enhancing your comprehension of how packet forwarding occurs in switched networks.