3com MSR 20-20 참조 매뉴얼

The default maximum number of MAC addresses that can be learned on a port 
varies with devices. When the upper limit is reached, frames received with 
unknown destination MAC addresses on a port are forwarded by default.

The command takes effect on the current port only when executed in interface 
view.

mac-address (system view), mac-address (Ethernet interface view), 
mac-address timer.

# Set the maximum number of MAC addresses that can be learned on port 
Ethernet 1/0 to 600. After this upper limit is reached, frames received with 
unknown destination MAC addresses on the port will not be forwarded.

<Sysname> system-view

[Sysname] interface ethernet 1/0

[Sysname-Ethernet1/0] mac-address max-mac-count 600

[Sysname-Ethernet1/0] mac-address max-mac-count disable-forwarding 

mac-address timer { aging seconds | no-aging }

System view

aging seconds: Sets a aging time for dynamic MAC address entries, in the range 
10 to 4080 seconds.

no-aging: Sets dynamic MAC address entries not to age.

Use the mac-address timer command to configure the aging timer for dynamic 
MAC address entries.

Use the undo mac-address timer command to restore the default value.

By default the aging timer for dynamic MAC address entries is 300 seconds.

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address table to retain outdated entries and fail to accommodate latest network 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.

# Set the aging timer for dynamic MAC address entries to 500 seconds.

<Sysname> system-view

[Sysname] mac-address timer aging 500