R3303-HP HSR6800 Routers Layer 2 - LAN Switching Configuration Guide

5
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 device deletes that entry. This aging mechanism makes sure the MAC address table can promptly
update to accommodate the most recent network changes.
Set the aging timer appropriately. Too long an 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retain outdated entries, exhaust the MAC address table resources, and fail to update its entries to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 most recent network changes. Too short an interval might result in removal of valid
entries, causing unnecessary floods, which could affect device performance.
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 }
Optional.
The default aging timer
for .dynamic MAC address entries
is 300 seconds.
The no-aging keyword disables the
aging timer.
You can reduce floods on a stable network by 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 you reduce the chances that a data packet will reach unintended destinations.
Configuring the MAC learning limit on ports
As the MAC address table grows, the forwarding performance of your device might degrade. To prevent
the MAC address table from getting so large that the forwarding performance degrades, you can limit
the number of MAC addresses that a port can learn.
To configure the MAC learning limit on a Layer 2 Ethernet interface, Layer 2 aggregate interface, or all
ports in a port group:
Step Command Remarks
1. Enter system view.
system-view N/A
2. Enter interface view or port
group view.
• Enter Layer 2 Ethernet or
aggregate interface view:
interface interface-type
interface-number
• Enter port group view:
port-group manual
port-group-name
Use either command.
Settings in interface view take
effect only on the specific interface.
Settings in port group view take
effect on all member ports in the
port group.