When a file is transferred in PASV mode, Sysax Multi Server needs to send back an IP Address and connection port to the client connection. If the Server is running inside a firewall or other secured environment, an IP address that is externally accessible is required. The Use IP Address checkbox is selected and the external IP Address is specified. The range of connection ports can also be restricted. The Restrict PASV port range checkbox is selected and the minimum and maximum port values are specified.