Natear un servidor FTP con un mikrotik
/ip firewall nat add action=dst-nat chain=dstnat comment="FTP server - command" disabled=no dst-address=IP_PUBLICA dst-port=21 in-interface=your_WAN_interface protocol=tcp to-addresses=IP_LOCAL to-ports=21 add action=dst-nat chain=dstnat comment="FTP server - data" disabled=no dst-address=IP_PUBLICA dst-port=55535-65534 in-interface=your_WAN_interface protocol=tcp to-addresses=IP_LOCAL to-ports=55535-65534