In this video, Tony Fortunato shows how TFTP can be problematic when transferring files between network devices.
In the past, transferring files to or from networking equipment wasn’t as common as it is now. I suspect this is largely due to many factors, including vendors updating their software to meet ever-challenging security risks and clients' interest in logs that may reside on the unit.
For example, when I was troubleshooting a problem with a Cisco router for a client, we needed to download the crash log for Cisco's Technical Assistance Center (TAC). I was a bit surprised when my client was not familiar – or comfortable -- with downloading a file from the router. In another situation, a client wanted me to figure out why Trivial File Transfer Protocol (TFTP) was slow or failing when uploading a new version of Cisco IOS to his router. To cut to the chase, I used File Transfer Protocol (FTP) and the upload finished in a fraction of the time. The client misunderstood and thought I had uncovered a bug, but I explained that TFTP is UDP based and not too forgiving where FTP) is TCP based and more likely to work where TFTP struggles.
I thought it would be helpful to duplicate the TFTP vs FTP performance issue. In this video, I used a WAN emulator from Apposite Technologies, Wireshark, and a Cisco router and provided an example of items that I document when performing an application baseline.
The two key point to take away from this:
- It doesn’t take that much time to perform a high-level comparison between two applications.
- When TFTP is taking too long, or not completing, you might want to try FTP.