3Com Switch 4800G 24-Port Configuration Manual page 175

n
Configuring MAC
Address Aging Timer
n
Configuring the
Maximum Number of
MAC Addresses an
Ethernet Port or a Port
Group Can Learn
Do not configure a static or dynamic MAC address entry on an aggregation port.
The MAC address table on your device is available with an aging mechanism for
dynamic entries to prevent its resources from being exhausted. Set the aging timer
appropriately: a long aging interval may cause the MAC address table to retain
outdated entries and fail to accommodate latest network changes; a short interval
may result in removal of valid entries and hence unnecessary broadcasts which
may affect device performance.
Follow these steps to configure the MAC address aging timer:
To do...
Enter system view
Configure the aging timer for
dynamic MAC address entries
The MAC address aging timer takes effect globally on dynamic MAC address
entries (learned or administratively configured) only.
To prevent a MAC address table from getting so large that it may degrade
forwarding performance, you may restrict the number of MAC addresses that can
be learned. One approach is to do this on a per-port or port group basis.
Follow these steps to configure the maximum number of MAC addresses that an
Ethernet port or port group can learn:
To do...
Enter system view
Enter Enter Ethernet port
Ethernet view
port or
Enter port group
port group
view
view
Configure the maximum
number of MAC addresses that
can be learned on an Ethernet
port or port group.
Configuring MAC Address Table Management
Use the command...
system-view
mac-address timer { aging
seconds | no-aging }
Use the command...
system-view
interface interface-type
interface-number
port-group { aggregation
agg-id | manual
port-group-name }
mac-address
max-mac-count count
175
Remarks
-
Optional
300 seconds by default.
Remarks
-
Required
Use either command to
configure on a port or ports
in a group.
Required
The maximum number of
MAC addresses that can be
learned on a port or port
group is not configured by
default.