Enables a csma-cd station entity which manages a CSMA-CD
    controller.

    enable  [node node-id] csma-cd station station-name -
            [,mac address address]

    MAC Address is an optional argument.  It specifies the
    individual medium access control address for the station. If
    you do not specify a MAC address, the network uses the address
    specified in the first EnableMacAddress user interface call
    directed to this station.

    Examples:

    enable csma station csmacd-1

    enable csma station csmacd-2 mac address 08-00-2B-11-19-68