Trivial File Transfer Protocol

TFTP Definition

TFTP stands for Trivial File Transfer Protocol. It's a technology for transferring files between network devices and is a simplified version of FTP (File Transfer Protocol).

TFTP was developed in the 1970s for computers lacking sufficient memory or disk space to provide full FTP support. Today, TFTP is also found on both consumer ​broadband routers and commercial network routers.

Home network administrators sometimes use TFTP to upgrade their router firmware, while professional administrators might also use TFTP to distribute software across corporate networks.

How TFTP Works

Like FTP, TFTP uses client and server software to make connections between two devices. From a TFTP client, individual files can be copied (uploaded) to or downloaded from the server. In other words, the server is the one serving files while the client is the one requesting or sending them.

TFTP can also be used to remotely start a computer and back up network or router configuration files.

TFTP uses UDP for transporting data.

TFTP Client and Server Software

Command line TFTP clients are included in current versions of Microsoft Windows, Linux, and macOS.

Some TFTP clients with graphical interfaces are also available as freeware, like TFTPD32, which includes a TFTP server. Windows TFTP Utility is another example of a GUI client and server for TFTP, but there are several other free FTP clients that you can use, too.

Microsoft Windows does not ship with a TFTP server but several free Windows TFTP servers are available for download. Linux and macOS systems typically use the tftpd TFTP server, although it might be disabled by default.

Networking experts recommend configuring TFTP servers carefully to avoid potential security issues.

How to Use the TFTP Client in Windows

The TFTP client in the Windows OS is not enabled by default. Here's how to turn it on through the Programs and Features Control Panel applet:

  1. Open Control Panel.
  2. Search for and open Programs and Features.
  3. Select Turn Windows features on or off from the left side of Control Panel to open "Windows Features." Another way to get to that window is to use enter the optionalfeatures command in Command Prompt or the Run dialog box.
  4. Scroll down in the "Windows Features" window and put a check in the box next to TFTP Client.

After it's installed, you can access TFTP through Command Prompt with the tftp command. Use the help command along with it (tftp /?) if you need information on how to use TFTP, or see the tftp command-line reference page on Microsoft's website.

TFTP vs. FTP

Trivial File Transfer Protocol differs from FTP in these key respects:

  • Original versions of TFTP only allowed transferring files up to 32 MB in size (some newer TFTP servers remove this restriction or might cap it out at 4 GB)
  • Unlike FTP, TFTP has no login feature, so it doesn't prompt for a username and password. It's therefore important to be careful to not use TFTP to share sensitive files
  • Listing, renaming, and deleting files over TFTP is usually not allowed but it is supported
  • TFTP uses UDP port 69 to establish network connections while FTP uses TCP ports 20 and 21

Because TFTP is implemented using UDP, it generally works only on local area networks (LANs).