Configuring an FTP Server
The File Transfer Protocol (FTP) is one of the oldest protocols in existence for sharing files over networks. While there are more secure protocols for network file sharing, FTP is still used quite often for making files freely available on the Internet.
Several FTP servers are available with Linux today. However, the one used by default with Fedora, Red Hat Enterprise Linux, and other Linux distributions is the Very Secure FTP Daemon (vsftpd package). This chapter describes how to install, configure, use, and secure an FTP server using the vsftpd package.
FTP operates in a client/server model. An FTP server daemon listens for incoming requests (on TCP port 21) from FTP clients. The client presents a login and password. If the server accepts the login information, the client can interactively traverse the filesystem, list files and directories, and then download (and sometimes upload) files.
What makes FTP insecure is that everything sent between the FTP client and server is done in clear text. The FTP protocol was created at a time when most computer communication was done on private lines or over dial-up, where encryption was not thought to be critical. If you use FTP over a public network, someone sniffing the line anywhere between the client and server ...