74 FTP AND TFTP C ONFIGURATIONFTP ConfigurationIntroduction to FTP FTP (file transfer protocol) is commonly used in IP-based networks to transmit files.Before World Wide Web comes into being, files are transferred through commandlines, and the most popular application is FTP. At present, although E-mail andWeb are the usual methods for file transmission, FTP still has its strongholds.As an application layer protocol, FTP is used for file transfer between remote serverand local host. TCP port 21 is used for control connections, and port 20 is used fordata connections. Basic FTP operations are described in RFC 959.FTP-based file transmission is performed in the following two modes:■ Binary mode, which is used for program file transfer.■ ASCII mode, which is used for text file transfer.An Ethernet switch can act as an FTP client or an FTP server in an FTPimplementation.■ FTP serverAn Ethernet switch can operate as an FTP server to provide file transmissionservices for FTP clients. You can log into a switch operating as an FTP server byrunning an FTP client program on your PC to access the files on the FTP server. Toaccept login requests, an FTP server must be assigned an IP address.Table 637 describes the configurations needed when a switch operates as an FTPserver.Table 637 Configurations needed when a switch operates as an FTP serverDevice Configuration Default DescriptionSwitch Enable the FTP serverfunctionThe FTP serverfunction is disabledby defaultYou can run thedisplay ftp-servercommand to view theFTP server configurationon the switch.Performauthentication-/authorization-relatedconfigurationBy default, FTP serverlogon authenticationand authorization arenot configured.Configure user names,passwords, and thework directory.Configure theconnection idle timeThe default idle timeis 30 minutes.-
