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An aging interval that is too long might cause the MAC address table to retains outdated entries. As a
result, the MAC address table resources might be exhausted, and the MAC address table might fail to
update to accommodate the latest network changes.
An interval that is too short might result in removal of valid entries, which would cause unnecessary floods
and possibly affect the device performance.
To reduce floods on a stable network, set a long aging timer or disable the aging timer to prevent
dynamic entries from unnecessarily aging out. Reducing floods improves the network performance.
Reducing flooding also improves the security because it reduces the chances for a data frame to reach
unintended destinations.
To configure the aging timer for dynamic MAC address entries:
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Configure the aging timer for
dynamic MAC address
entries.
mac-address timer
{
aging
seconds
|
no-aging
}
By default, the aging timer for
dynamic MAC address entries is
300 seconds
The
no-aging
keyword disables the
aging timer.
Configuring the MAC learning limit on an interface
To prevent the MAC address table from getting too large, limit the number of MAC addresses that can be
learned on an interface.
To configure the MAC learning limit on an interface:
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter Layer 2 Ethernet
interface view.
interface
interface-type
interface-number
N/A
3.
Configure the MAC learning
limit on the interface.
mac-address max-mac-count
count
By default, no maximum number of
MAC addresses that can be
learned on an interface is
configured.
Configuring the device to forward unknown frames
after the MAC learning limit on an interface is
reached
NOTE:
In this document, unknown frames refer to frames whose source MAC addresses are not in the MAC
address table.