H3C Technologies H3C S12500-X Series Switches - Manual (Page 37)

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Set the aging timer appropriately. A stable network requires a longer aging interval and an unstable
network requires a shorter aging interval. A too long aging interval 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to retain outdated entries, exhaust the MAC address table resources, and fail to update its entries to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. A too short interval might result in removal of valid entries,
causing unnecessary floods, which might increase network burden.
You can reduce floods on a stable network by setting a long aging timer or disabling the aging timer to
prevent dynamic entries from unnecessarily aging out. By reducing floods, you improve not only network
performance, but also security, because the chances for a data frame to reach unintended destinations
are reduced.
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 interfaces
To prevent a large MAC address table from degrading forwarding performance, 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 frame forwarding rule
You can determine whether to allow the device to forward frames with unknown source MAC addresses
after the upper limit is reached.
To enable the interface to forward frames with unknown source MAC addresses after the upper limit is
reached:
Step Command Remarks
1. Enter system view. system-view N/A