14-14
Configuring and Monitoring Port Security     
Port Security
Syntax: port-security (Continued)
learn-mode < continuous | static | port-access  | configured | limited-
continuous > (Continued)
Caution: Using the
 static parameter with a device limit 
greater than the number of MAC addresses specified 
with mac-address can allow an unwanted device to 
become “authorized”. This is because the port, to fulfill 
the number of devices allowed by the address-limit 
parameter (se below), automatically adds devices it 
detects until it reaches the specified limit. 
Note: If 802.1X port-access is configured on a given port, 
then port-security learn-mode must be set to either 
continuous (the default) or port-access.
port-access: Enables you to use Port Security with 
(802.1X) Port-Based Access Control. Refer to chapter 13, 
Configuring Port-Based and User-Based Access Control 
(802.1X).
configured: Must specify which MAC addresses are allowed 
for this port. Range is 1 (default) to 8 and addresses are 
not ageable. Addresses are saved across reboots.
limited-continuous: Also known as MAC Secure, or “limited” 
mode. The limited parameter sets a finite limit to the 
number of learned addresses allowed per port. (You can 
set the range from 1, the default, to a maximum of 32 MAC 
addresses which may be learned by each port.)
All addresses are ageable, meaning they are automatically 
removed from the authorized address list for that port 
after a certain amount of time. Limited mode and the 
address limit are saved across reboots, but addresses 
which had been learned are lost during the reboot process.
Addresses learned in the limited mode are normal 
addresses learned from the network until the limit is 
reached, but they are not configurable. (You cannot enter 
or remove these addresses manually if you are using learn-
mode with the limited-continuous option.)
—Continued—