83FTP configurationFTP overviewIntroduction to FTPThe File Transfer Protocol (FTP) is an application layer protocol used to share files between server andclient over a TCP/IP network.FTP uses TCP ports 20 and 21. Port 20 is used to transmit data, and port 21 is used to transmit controlcommands. For more information about FTP basic operations, see RFC 959.FTP transfers files in the following modes:• Binary mode—Transfers files as raw data, such as .app and .bin files.• ASCII mode—Transfers files as text, such as .txt, .bat, and .cfg files.FTP operates in either of the following modes:• PORT mode—Active mode, in which the FTP server initiates a data connection request. This modeis unavailable when the FTP client is behind a firewall.• PASV mode—Passive mode, in which the FTP client initiates a data connection request. This modeis unavailable when the server side does not allow the client to connect to a random unprivilegedport (>1024).The FTP operation mode varies with FTP client programs.FTP operationFTP adopts the client/server model. Your device can function either as the client or the server. See Figure36.• When the device serves as the FTP client, a user can Telnet to it from a PC, and execute the ftpcommand to establish a connection to the remote FTP server on the PC to upload/download filesto/from the PC.• When the device serves as the FTP server, a user can FTP to the device from a PC that runs the FTPclient and upload/download files to/from the device.Figure 36 Network diagramWhen the device serves as the FTP client, you need to perform the following configuration:
