The optional SAP argument specifies the Service Access Point on
    the target system to which the XID message is to be sent.  SAP is
    an octet (00-FF).  The default SAP is 00.

    test  [node node-id] mop circuit circuit-name -
          address lan-address, -
          sap octet [,optional arguments...]

    If an Address is not supplied in the command on a LAN circuit,
    then the Client argument must be specified so the address
    information can be obtained from the MOP Client database.

    test  [node node-id] mop circuit circuit-name -
          client client-name, -
          sap octet [,optional arguments...]

    Examples:

    test mop circuit csmacd-1 address 08-00-2b-00-13-4F, sap ff

    test mop circuit fddi-1 client mynode, sap 55