The MAC locking security feature provides for limiting access to a port to specified MAC addresses or a maximum number of MAC addresses on a first come first serve basis. In the first case, a device with a MAC address that is not specifically configured will not be allowed access to a port. This provides the network administrator with confidence that only known devices will gain access to a port. The second case provides a means of controlling the maximum number of unique devices that will have access at any given time to the port configured for this mode of MAC locking.