H3C Technologies H3C WX3000 Series Unified Switches - Manual (Page 167)

21-6
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When you add a MAC address entry, the current port must belong to the VLAN specified by the
vlan argument in the command. Otherwise, the entry will not be added.
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If the VLAN specified by the vlan argument is a dynamic VLAN, after a static MAC address is
added, it will become a static VLAN.
Setting the Aging Time of MAC Address Entries
Setting aging time properly helps effective utilization of MAC address aging. The aging time that is too
long or too short affects the performance of the device.
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If the aging time is too long, excessive invalid MAC address entries maintained by the device may
fill up the MAC address table. This prevents the MAC address table from being updated with
network changes in time.
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If the aging time is too short, the device may remove valid MAC address entries. This decreases
the forwarding performance of the device.
Follow these steps to set the aging time of MAC address entries:
To do… Use the command… Remarks
Enter system view system-view —
Set the aging time of MAC
address entries mac-address timer { aging age |
no-aging }
Required
The default aging time is 300 seconds.
Normally, you are recommended to use the default aging time, namely, 300 seconds. The no-aging
keyword specifies that MAC address entries do not age out.
MAC address aging configuration applies to all ports, but only takes effect on dynamic MAC addresses
that are learnt or configured to age.
Setting the Maximum Number of MAC Addresses a Port Can Learn
The MAC address learning mechanism enables the device to acquire the MAC addresses of the
network devices on the segment connected to the ports of the device. By searching the MAC address
table, the device directly forwards the packets destined for these MAC addresses through the hardware,
improving the forwarding efficiency. A MAC address table too big in size may prolong the time for
searching MAC address entries, thus decreasing the forwarding performance of the device.
By setting the maximum number of MAC addresses that can be learned from individual ports, the
administrator can control the number of the MAC address entries the MAC address table can