2-12 TFTP ConfigurationWhen configuring TFTP, go to these sections for information you are interested in:z Introduction to TFTPz TFTP ConfigurationIntroduction to TFTPCompared with FTP, Trivial File Transfer Protocol (TFTP) features simple interactive access interfaceand no authentication control. Therefore, TFTP is applicable in the networks where client-serverinteractions are relatively simple. TFTP is implemented based on UDP. It transfers data through UDPport 69. Basic TFTP operations are described in RFC 1986.TFTP transmission is initiated by clients, as described in the following:z To download a file, a client sends Read Request packets to the TFTP server, then receives datafrom the TFTP server, and sends acknowledgement packets to the TFTP server.z To upload a file, a client sends Write Request packets to the TFTP server, then sends data to theTFTP server, and receives acknowledgement packets from the TFTP server.A 3com switch 4500 can act as a TFTP client only.When a 3com switch 4500 serving as a TFTP client downloads files from the TFTP server, theseven-segment digital LED on the front panel of the switch rotates clockwise, and it stops rotating whenthe file downloading is finished, as shown in Figure 1-1.When you download a file that is larger than the free space of the switch’s flash memory:z If the TFTP server supports file size negotiation, file size negotiation will be initiated between theswitch and the server and the file download operation will be aborted if the free space of theswitch’s flash memory is found to be insufficient.z If the TFTP server does not support file size negotiation, the switch will receive data from the serveruntil the flash memory is full. If there is more data to be downloaded, the switch will prompt that thespace is insufficient and delete the data partially downloaded. File download fails.TFTP-based file transmission can be performed in the following modes:z Binary mode for program file transfer.z ASCII mode for text file transfer.Before performing TFTP-related configurations, you need to configure IP addresses for the TFTP clientand the TFTP server, and make sure a route exists between the two.
