Huawei Quidway S3900 series Command Manual page 241

Command Manual – MAC Address Table
Quidway S3900 Series Ethernet Switches-Release 1510
Description
Use the mac-address timer command to set the aging time for dynamic MAC address
entries.
Use the undo mac-address timer command to restore the default aging time.
Set the aging time of dynamic MAC address entries as required but ensure that the
aging time does not decrease the layer 2 packet forwarding performance of the switch.
If the aging time is too short, the MAC address entries that are still valid may be
removed. Upon receiving a packet destined for a MAC address that is already
removed, the switch broadcasts the packet through all its ports in the VLAN which
the packet belongs to. This decreases the operating performance of the switch.
If the aging time is too long, MAC address entries may still exist even if they turn
invalid. This causes the switch to be unable to update its MAC address table in
time. In this case, the MAC address table cannot reflect the position changes of
network devices in time.
Example
# Set the aging time of MAC address entries to 500 seconds.
<Quidway> system-view
System View: return to User View with Ctrl+Z.
[Quidway] mac-address timer aging 500
Huawei Technologies Proprietary
1-7
Chapter 1 MAC Address Table Configuration
Commands