Port Security

Port security is a security feature of Cisco switches.

It allows you to control which source MAC address(es) are allowed to enter the switchport.

If an unauthorized source MAC address enters the port, an action will be taken.

• The default action is to place the interface in an 'err-disabled' state.

When you enable port security on an interface with the default settings, one MAC address is allowed.

• You can configure the allowed MAC address manually.

• If you don't configure it manually, the switch will allow the first source MAC address that enters the interface.

You can change the maximum number of MAC addresses allowed.

A combination of manually configured MAC addresses and dynamically learned addresses is possible.