Setting The Mac Learning Limit; Configuration Restrictions And Guidelines; Setting The Mac Learning Limit On An Interface - H3C S7500X Series Configuration Manual

An aging interval that is too long might cause the MAC address table to retain outdated entries. As a
result, the MAC address table resources might be exhausted, and the MAC address table might fail
to update its entries 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 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 set the aging timer for dynamic MAC address entries:
Step
1. Enter system view.
2. Set the aging timer for
dynamic MAC address
entries.

Setting the MAC learning limit

Configuration restrictions and guidelines

In an IRF 3.1 system, interfaces and VLANs on PEXs do not support this feature. For more
information about PEXs, see Virtual Technologies Configuration Guide.
The MAC address learning limit does not take manually configured dynamic MAC addresses into
account.
This feature does not take effect when MAC-based VLANs or voice VLANs are configured or MAC
authentication is performed. For more information about MAC-based VLANs and voice VLANs, see
"Configuring VLANs" and "Configuring voice VLANs." For more information about MAC
authentication, see Security Configuration Guide.
For the MAC learning limit feature to function correctly, do not configure this feature in both interface
view and VLAN view.
If you configure this feature in the view of a VLAN, only basic VLAN commands and port-based
VLAN commands are supported on the VLAN. For more information, see VLANs in Layer 2—LAN
Switching Command Reference.

Setting the MAC learning limit on an interface

This feature limits the MAC address table size. A large MAC address table will degrade forwarding
performance.
If you set the MAC learning limit on a member port of an aggregation group, the setting takes effect
only after the member port is removed from the aggregation group.
To set the MAC learning limit on an interface:
Step
1. Enter system view.
2. Enter Layer 2 Ethernet
interface view.
Command
system-view
mac-address timer { aging
seconds | no-aging }
Command
system-view
interface interface-type
interface-number
7
Remarks
N/A
The default setting is 300
seconds.
The no-aging keyword disables
the aging timer.
Remarks
N/A
N/A