Cisco Systems 3750E manual Understanding Port Security, Secure MAC Addresses, 26-8

Chapter 26 Configuring Port-Based Traffic Control

Configuring Port Security

These sections contain this conceptual and configuration information:

•Understanding Port Security, page 26-8

•Default Port Security Configuration, page 26-10

•Port Security Configuration Guidelines, page 26-10

•Enabling and Configuring Port Security, page 26-12

•Enabling and Configuring Port Security Aging, page 26-16

•Port Security and Switch Stacks, page 26-17

•Port Security and Private VLANs, page 26-17

Understanding Port Security

These sections contain this conceptual information:

•Secure MAC Addresses, page 26-8

•Security Violations, page 26-9

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-securitymac-addressmac-addressinterface 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.

You can configure an interface to convert the dynamic MAC addresses to sticky secure MAC addresses and to add them to the running configuration by enabling sticky learning. To enable sticky learning, enter the switchport port-securitymac-address sticky interface configuration command. When you enter this command, the interface converts all the dynamic secure MAC addresses, including those that were dynamically learned before sticky learning was enabled, to sticky secure MAC addresses. All sticky secure MAC addresses are added to the running configuration.

The sticky secure MAC addresses do not automatically become part of the configuration file, which is the startup configuration used each time the switch restarts. If you save the sticky secure MAC addresses in the configuration file, when the switch restarts, the interface does not need to relearn these addresses. If you do not save the sticky secure addresses, they are lost.

Catalyst 3750-E and 3560-E Switch Software Configuration Guide

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