I have the strangest problem with ftp. Immediately after a reboot the windows command line ftp program works fine.
Then, I try to use a friendlier ftp client (TotalCommander, which I have used for years) and it can log in, get folder contents, everything works until I try to upload a file. Then it seems that the connection gets suddenly closed -- and ftp ability is thereafter damaged.
Here is the strange part: ftp upload seems to then be permanently broken. And the way it is broken is quite strange. I go back to the command line ftp client, and I can connect, list folders, change folders, download files of any size, upload small files <2Kbytes, BUT upload of a file bigger than 2K causes the connection to be dropped, and the command times out.
Reboot the OS (64 bit Win 7) and everything is fine again.
I have disabled the windows firewall since many discussions centered on this. The behavior is the same whether windows firewall is on or off.
I have tried toggling PASV mode, and again, the behavior is the same whether sending passive or not.
I have tried in both binary and ASCII mode, and the behavior is the same.
This problem began when I reinstalled the Windows 7 Enterprise, Service Pack 1 on a new disk. Installed all 146+ patches and updates.
Network is not a problem: no problems with my laptop connected to the same network. No problems with the remote server when accessed from other machines. It is clearly isolated to this new installation of windows.
Any ideas at all how running one program could cause the command line ftp to become unable to send files if they are >2k?
The problem has magically gone away, and this question has won me the time honored "Tumbleweed" badge.
While it is inconclusive, the problem appeared to be something with the network driver. The application was making a request that somehow put the driver in a mode which would limit sending (only for ftp as far as I know) to less than 2K. I reinstalled the latest network driver and latest chipset drivers, rebooted a number of times, to no effect. However, I installed the HP Printer driver, and poof, the problem went away. This might simply be a coincidence, or there might be some OS utility that got updated as a result. If anyone has clues as to why installing HP printer software would fix a network card, please share.