NOTE:
•
When MAC address learning is disabled, the obtained MAC addresses remain valid until they age out
•
For more information about port groups, see the chapter “Ethernet interface configuration.”
Disabling MAC address learning on a VLAN (available only on the A3100 v2 EI)
You can disable MAC address learning on a per-VLAN basis.
Follow these steps to disable MAC address learning on a VLAN:
To do…
Use the command…
Remarks
Enter system view
system-view
—
Enter VLAN view
vlan
vlan-id
—
Disable MAC address learning on
the VLAN
mac-address mac-learning disable
Required
Enabled by default.
NOTE:
When MAC address learning is disabled, the obtained MAC addresses remain valid until they age out.
Configuring the aging timer for dynamic MAC address entries
The MAC address table uses an aging timer for dynamic MAC address entries for security and efficient
use of table space. If a dynamic MAC address entry has failed to update before the aging timer expires,
the switch deletes the entry. This aging mechanism ensures that the MAC address table can quickly
update to accommodate the latest network changes.
Set the aging timer appropriately. An aging interval that is too long might cause the MAC address table
to retain outdated entries, exhaust the MAC address table resources, and fail to update its entries to
accommodate the latest network changes. An interval that is too short might result in the removal of valid
entries and unnecessary broadcasts, which might affect device performance.
Follow these steps to configure the aging timer for dynamic MAC address entries:
To do…
Use the command…
Remarks
Enter system view
system-view
—
Configure the aging timer for
dynamic MAC address entries
mac-address timer
{
aging
seconds
|
no-aging
}
Optional
300 seconds by default.
You can reduce broadcasts on a stable network by disabling the aging timer to prevent dynamic entries
from unnecessarily aging out. By reducing broadcasts, you improve not only network performance, but
also security, because you reduce the chances that a data packet will reach unintended destinations.
Configuring the MAC learning limit on ports
To prevent the MAC address table from getting too large, you can limit the number of MAC addresses
that a port can obtain.
Follow these steps to configure the MAC learning limit on a Layer 2 Ethernet interface or all ports in a port
group:
20