Allied Telesis AT 8000/8POE - Manual (Page 206)

Chapter 16: MAC Address Tables
206 Section I: Using the Menus Interface
Setting the Age-Out Time
The switch uses the age-out time to delete inactive MAC addresses from
the MAC address table. When the switch detects that no packets have
been sent to or received from a particular MAC address in the table after
the period specified by the aging time, the switch deletes the address. This
prevents the table from becoming full of addresses of nodes that are no
longer active.
The default for the age-out time is 300 seconds (5 minutes).
To adjust the age-out time, perform the following procedure:
1. From the MAC Address Table menu, select one of the MAC address
display options.
2. On the MAC address display menu, type A to select Set Age-Out
Time.
The following prompt is displayed:
Enter new age-out time>
The range is 15 to 3000 seconds.
3. Enter a new number for the age-out time.