Cisco Port-Security

How to set the number of mac-addresses allowed on a secure switch port. This is useful if you have setup swtichport security, but want to allow one or more ports to be used by multiple machines or virtual machines. This is how you enable more than one mac-address on a port.
When you have logged onto the switch and entered the enable mode. Enter the configuration terminal,
    conf term
    interface <interface name>
    switchport port-security maximum <max num of macs>
This will allow a maximum of <max num of macs> mac addresses on the switch interface <interface name>. The "switchport port-security" conf section also allows you to enable/disable security all together and set the violation policy (ie what to do if the settings are violated).