The optional Length argument specifies the length of the test
    data part of each message. The maximum and minimum permitted
    values depend on the particular data link in use.  The range is
    0-4294967295.  The default length is 40.

    test [node node-id] mop client client-name -
         length integer [,optional arguments...]

    If an Address and Circuit are not supplied by the MOP client
    database, then that information must be provided in the command:

    test [node node-id] mop client client-name -
         circuit circuit-name, -
         address lan-address, -
         length integer [,optional arguments...]

    Examples:

    test mop client lamchp -     ! Client gives Address and Circuit
         length 20

    test mop client lamchp -       ! Client gives default Address
         circuit fddi-1, length 45