252 CHAPTER 11: SYSTEM MANAGEMENT
By default, the MAC address learning function is enabled.
Setting MAC Address Aging Time
Setting an appropriate aging time implements MAC address aging. Too long or
too short an aging time set by subscribers will cause the Ethernet switch to flood a
large amount of data packets. This affects the switch operation performance.
If aging time is set too long, the Ethernet switch stores a great number of
out-of-date MAC address tables. This consumes MAC address table resources and
the switch will not be able to update the MAC address table according to the
network change.
If aging time is set too short, the Ethernet switch may delete valid MAC address
table entries.
You can use the following commands to set the MAC address aging time for the
system.
Perform the following configuration in system view.
In addition, this command takes effect on all the ports. However, the address
aging only functions on the dynamic addresses (the learned or configured as age
entries by the user).
By default, the aging-time is 300 seconds. With the no-aging parameter, the
command performs no aging on the MAC address entries.
Displaying and Debugging the MAC Address Table
Execute the display command in all views to display the MAC address table
configuration, and to verify the effect of the configuration.
Execute the debugging command in user view to debug MAC address table
configuration.
Tabl e 274 Setting the MAC Address Aging Time for the System
Operation Command
Set the dynamic MAC address aging time mac-address timer { aging age |
no-aging }
Restore the default MAC address aging time undo mac-address timer aging-time
Tabl e 275 Displaying and Debugging MAC Address Table
Operation Command
Display the information in the address table display mac-address [ static |
dynamic ] [ [ interface {
interface-name | interface-type
interface-num } ] [ vlan vlan-id ]
]
Display the aging time of dynamic address
table entries
display mac-address aging-time
Display the dynamic MAC address learning
capability of the system and ports
display mac-address learning [
interface-type interface-num |
interface-name ]