Standard TCP/IP Services

• FTP and Anonymous FTP - The File Transfer Protocol (FTP) transfers files to and from a remote network. The protocol includes the ftp command (local machine) and the in.ftpd daemon (remote machine). FTP enables a user to specify the name of the remote host and file transfer command options on the local host's command line. The in.ftpd daemon on the remote host then handles the requests from the local host. Unlike rcp, ftp works even when the remote computer does not run a UNIX-based operating system. A user must log in to the remote computer to make an ftp connection unless it has been set up to allow anonymous FTP.

  You can now obtain a wealth of materials from anonymous FTP servers connected to the Internet. These servers are set up by universities and other institutions to make certain software, research papers, and other information available to the public domain. When you log in to this type of server, you use the login name anonymous, hence the term "anonymous FTP servers."

  Using anonymous FTP and setting up anonymous FTP servers is outside the scope of this manual. However, many trade books, such as The Whole Internet User's Guide & Catalog, discuss anonymous FTP in detail. Instructions for using FTP to reach standard machines are in System Administration Guide, Volume 1. The ftp(1) man page describes all ftp command options, including those invoked through the command interpreter. The ftpd(1M) man page describes the services provided by the daemon in.ftpd.

• Telnet - The Telnet protocol enables terminals and terminal-oriented processes to communicate on a network running TCP/IP. It is implemented as the program telnet (on local machines) and the daemon in.telnet (on remote machines). Telnet provides a user interface through which two hosts can communicate on a character-by-character or line-by-line basis. The application includes a set of commands that are fully documented in the telnet(1) man page.

• TFTP - The trivial file transfer protocol (tftp) provides functions similar to ftp, but it does not establish ftp's interactive connection. As a result, users cannot list the contents of a directory or change directories. This means that a user must know the full name of the file to be copied. The tftp(1) man page describes the tftp command set.