The File Transfer Protocol (FTP) is one of the oldest members of the TCP/IP protocol stack, yet it is still in common use today. As the name suggests, it is optimized for transferring files. While you can also download a file through an alternative protocol (such as HTTP) or an encrypted service (such as SFTP), FTP is faster. I use FTP to download the CD files whenever Red Hat releases a new version of their Linux distribution; for me, with my DSL connection, the FTP download speeds over the same transmission media are twice as fast as with HTTP.
As with other services, there are FTP clients and FTP servers. A rich variety of commands are associated with FTP clients; you can even upgrade RPMs directly with the right ftp command. And of course, GUI FTP clients exist that work just as well.
Many FTP servers are available for Linux, and in this chapter we cover two of them: very secure FTP (vsFTP) and Washington University s (St. Louis) WU-FTP. Both servers can be configured to allow anonymous users. vsFTP is now the default; WU-FTP was the default FTP server through Red Hat Linux 8.0 (but is not included with Red Hat Linux 9). While neither server is truly secure, each has its own configuration file to control users and computers that are allowed access. Both have ways of protecting the other files and directories on your system. This chapter covers the following topics:
Using FTP as a client
Configuring the secure FTP server
Creating an anonymous FTP server
Using FTP servers with real users