Here is a little bit about my environment, I just received 10 used 2950 LRE's with a 12.1.14 IOS loaded on them. I am in the process of upgrading them all to 12.1.22-EA4 using TFTP and the basic "copy tftp flash" command. The problem is that 7 out of 10 of them fail at about 70% completion. I receive an error message stating that "error accessing TFTP server at IP x.x.x.x."
Now again, some of these are able to be upgraded without a problem. I was originally using TFTP dekstop, but then switched the the Solarwinds TFTP app, but the upgrade fails at approx the same place each time. I have even gone back on to the Cisco web site and downloaded the IOS image again to make sure that it was not corrupt, but the same failure happens.
Thanks in advance, and let me know if there is anything else that you need.