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Cisco ME 3400 Ethernet Access Switch Software Configuration Guide
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Chapter 22 Configuring Port-Based Traffic Control Configuring Port Security
Configuring Port Security
You can use the port security feature to restrict input to an interface by limiting and identifying MAC
addresses of the stations allowed to access the port. When you assign secure MAC addresses to a secure
port, the port does not forward packets with source addresses outside the group of defined addresses. If
you limit the number of secure MAC addresses to one and assign a single secure MAC address, the
workstation attached to that port is assured the full bandwidth of the port.
If a port is configured as a secure port and the maximum number of secure MAC addresses is reached,
when the MAC address of a station attempting to access the port is different from any of the identified
secure MAC addresses, a security violation occurs. Also, if a station with a secure MAC address
configured or learned on one secure port attempts to access another secure port, a violation is flagged.
These sections contain this conceptual and configuration information:
• Understanding Port Security, page 22-9
• Default Port Security Configuration, page 22-11
• Port Security Configuration Guidelines, page 22-11
• Enabling and Configuring Port Security, page 22-12
• Enabling and Configuring Port Security Aging, page 22-16
• Port Security and Private VLANs, page 22-17

Understanding Port Security

These sections contain this conceptual information:
• Secure MAC Addresses, page 22-9
• Security Violations, page 22-10

Secure MAC Addresses

You configure the maximum number of secure addresses allowed on a port by using the switchport
port-security maximum value interface configuration command.
Note If you try to set the maximum value to a number less than the number of secure addresses already
configured on an interface, the command is rejected.
The switch supports these types of secure MAC addresses:
• Static secure MAC addresses—These are manually configured by using the switchport
port-security mac-address mac-address interface configuration command, stored in the address
table, and added to the switch running configuration.
• Dynamic secure MAC addresses—These are dynamically configured, stored only in the address
table, and removed when the switch restarts.
• Sticky secure MAC addresses—These can be dynamically learned or manually configured, stored in
the address table, and added to the running configuration. If these addresses are saved in the
configuration file, when the switch restarts, the interface does not need to dynamically reconfigure
them.