Reference Guide

When you enable sticky mac on an interface, dynamically-learned MAC addresses do not age, even if you enabled
mac-learning-limit dynamic. If you configured mac-learning-limit and mac-learning-limit
dynamic and you disabled sticky MAC, any dynamically-learned MAC addresses ages.
mac learning-limit station-move
The mac learning-limit station-move command is available on the Z-Series platform.
The station-move option, allows a MAC address already in the table to be learned off of another interface. For
example, if you disconnect a network device from one interface and reconnect it to another interface, the MAC address
is learned on the new interface. When the system detects this “station move,” the system clears the entry learned on
the original interface and installs a new entry on the new interface.
mac learning-limit no-station-move
The no-station-move option, also known as “sticky MAC,” provides additional port security by preventing a station
move.
When you configure this option, the first entry in the table is maintained instead of creating an entry on the new
interface. no-station-move is the default behavior. Entries created before you set this option are not affected.
To display a list of all interfaces with a MAC learning limit, use the following command.
Display a list of all interfaces with a MAC learning limit.
EXEC Privilege mode
show mac learning-limit
FTOS Behavior: The systems do not generate a station-move violation log entry for physical interfaces or port-channels
when you configure mac learning-limit or when you configure mac learning-limit station-move-
violation log. FTOS detects a station-move violation only when you configure mac learning-limit
dynamic and logs the violation only when you configure the mac learning-limit station-move-
violation log
, as shown in the following example.
FTOS(conf-if-gi-1/1)#show config
!
interface GigabitEthernet 1/1
no ip address
switchport
mac learning-limit 1 dynamic no-station-move
mac learning-limit station-move-violation log
no shutdown
Learning Limit Violation Actions
Learning limit violation actions are supported only on the Z9000 platform.
To configure the system to take an action when the MAC learning limit is reached on an interface and a new address is
received using one the following options with the mac learning-limit command, use the following commands.
• Generate a system log message when the MAC learning limit is exceeded.
INTERFACE mode
learn-limit-violation log
• Shut down the interface and generate a system log message when the MAC learning limit is exceeded.
INTERFACE mode
learn-limit-violation shutdown
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