Performs a loop operation with another system.

    loop [node node-id] mop client client-name [,optional args...]

    For a LAN circuit, if there is no default Address and Circuit
    information specified for this client in the MOP Client database,
    then that information must be specified on the command line.

    loop  [node node-id] mop client client-name -
          address lan-address, -
          circuit circuit-name [,optional arguments...]

    Optional arguments for this loop mop client command are:
    Assistance Type, Assistant Address, Assistant System, Count,
    Format, and Length.

    Examples:

    loop mop client lamchp    ! Client provides Address and Circuit.

    loop mop client lamchp -  ! Overrides default Circuit
         circuit csmacd-1     ! provided by Client