Sends ICMP ECHO packets to hosts to determine whether they are
    active. Same as the PING command.
    Format
      LOOP  [ host ]
            [ /ADDRESS=xx.xx.xx.xx ]
            [ /ALL ]
            [ /FULL ]
            [ /NUMBER_PACKETS=n ]
            [ /PACKET_SIZE=n ]
            [ /PATTERN="hexadecimal-string" ]
            [ /[NO]ROUTE ]
            [ /WAIT=n ]