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 the remote computer has been configured to allow anonymous FTP.
You can now obtain an enormous amount of materials from anonymous FTP servers that are connected to the Internet. Universities and other institutions set up these servers to offer software, research papers, and other information 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 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: Resource Management and Network Services. The ftp(1) man page describes all ftp command options that are invoked through the command interpreter. The ftpd(1M) man page describes the services that are provided by the daemon in.ftpd.
Telnet – The Telnet protocol enables terminals and terminal-oriented processes to communicate on a network that runs TCP/IP. This protocol is implemented as the program telnet (on local machines) and the daemon in.telnetd (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 that are similar to ftp, but the protocol does not establish ftp's interactive connection. As a result, users cannot list the contents of a directory or change directories. A user must know the full name of the file to be copied. The telnet(1) man page describes the tftp command set.