3Com Switch 8800 Configuration Guide
Chapter 44 MAC Address Table Management
44-3
If aging time is set too short, the Ethernet switch may delete valid MAC address table.
You can use the following commands to set the MAC address aging time for the
system.
Perform the following configuration in system view.
Table 44-2
Set the MAC address aging time for the system
Operation
Command
Set the dynamic MAC address aging
time
mac-address timer
{
aging
age
|
no-aging
}
Restore the default MAC address
aging time
undo mac-address timer
aging
In addition, this command takes effect on all the ports. However the address aging only
functions on the dynamic addresses (the learned or configured as age entries by the
user).
By default, the
aging
-
time
is 300 seconds. With the
no
-
aging
parameter, the command
performs no aging on the MAC address entries.
Caution:
The dynamic MAC address aging is completed during the second aging cycle.
44.3 Maximum MAC Address Number Learned by Ethernet
Port and Forwarding Option Configuration
With MAC address learning, an Ethernet switch can obtain MAC addresses of every
network devices on network segments connecting to a port. As for packets destined to
those MAC addresses, the switch directly uses hardware to forward them. An overlarge
MAC address table may cause the low forwarding performance of the switch.
You can control the number of entries of the MAC address table by setting the
maximum number of MAC addresses learned by a port. if you set the value to
count
,
and when the number of MAC addresses learned by the port reaches this value, this
port will no longer learn any more MAC addresses.
You can also set the switch to drop corresponding packets when the number of MAC
addresses learned by the port exceeds the configured threshold.
