The Standard TFTP Client

In this assignment we will use the TFTP client supported by the operating system to contact the server we are about to implement. In the following session we show how to use the client to fetch a file (RFC1350.txt) from a TFTP server on a remote machine. The port we use here is the default TFTP port (69), and it should be changed to the actual port the server listens to. Unix systems provide a client operating in interactive mode:

# tftp (Starts client program)
connect localhost 69 (Defines remote endpoint)
tftp> mode octet (Defines transport mode)
tftp> get RFC1350.txt (Read request for RFC1350.txt)
Received 2360 bytes in 0.0 seconds 
tftp> quit (Terminate session)

It is as easy as it looks. After we have started the client program, we define the remote endpoint and transport mode to be used. Once this is done we can make one or more requests to the server. We use get filename to read a file from the server and put filename to write a file to the server. If we try to read files that doesn’t exist, or write to files that already exist, an error message will be received and displayed. We can not change directory at the remote machine, nor can we list the available files. The only thing we can do is access files from two preassigned directories (read and write) at the machine hosting the server.

If you use Windows, the standard TFTP client lacks such an important option as server port selection. Therefore, we suggest using TFTPD32 application which provides TFTP client (as well as server) implementation with number of options.