Cisco me 3400 Guide De Référence

Use the mac address-table aging-time global configuration command to set the length of time that a 
dynamic entry remains in the MAC address table after the entry is used or updated. Use the no form of 
this command to return to the default setting. The aging time applies to all VLANs or a specified VLAN.

mac address-table aging-time {0 | 10-1000000} [vlan vlan-id]

no mac address-table aging-time {0 | 10-1000000} [vlan vlan-id]

The default is 300 seconds.

Global configuration

If hosts do not send continuously, increase the aging time to record the dynamic entries for a longer time. 
Increasing the time can reduce the possibility of flooding when the hosts send again.

If you do not specify a specific VLAN, this command sets the aging time for all VLANs.

This example shows how to set the aging time to 200 seconds for all VLANs:

Switch(config)# mac address-table aging-time 200

You can verify your setting by entering the show mac address-table aging-time privileged EXEC 
command.

This value disables aging. Static address entries are never aged or removed from 
the table.

Aging time in seconds. The range is 10 to 1000000 seconds.

vlan vlan-id

(Optional) Specify the VLAN ID to which to apply the aging time. The range is 
1 to 4094. 

12.2(25)EX

This command was introduced.

Displays the MAC address table aging time for all VLANs 
or the specified VLAN.