Users Guide

To save all sticky MAC addresses into a configuration file that can be used as a startup configuration file,
use the write config command. If the number of existing MAC addresses is fewer than the configured
MAC learning limit, additional MAC addresses are converted to sticky MACs addresse on the port. To
remove all sticky MAC addresses from the running configuration file, disable sticky MAC and enter the
write config command.
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 address ages.
mac learning-limit station-move
The mac learning-limit station-move command allows a MAC address already in the table to be
learned from 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
Learning Limit Violation Actions
Learning limit violation actions are user-configurable.
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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