421 Timeout after large file transfer

[suctionman]

I have been using Filezilla for small scripts and images without problems, but the last couple of days I have been trying to upload a 200mb file to my server. The process all seems to work properly (I sit and wait 40 minutes for the transfer to be completed), but once it reaches 100% a box asking me if I want to replace the file I just uploaded with the same file again pops up. I click cancel, because I don't want to sit waiting for it to upload again for another 40 minutes (which is what happens). The message log reads:

Response: 421 Timeout.
Error: Disconnected from server

and the transfer is moved to 'Failed transfers' with the error 'timeout'. I have a keep-alive in place, and the timeout variable is set to 0. The file I am trying to upload will be on the server after all this, at least most of it, but clearly a few last bits haven't made it because the data is corrupt when I re-download it.

Thanks for any help.

[boco]

Firewall/router/Antivirus/'security' software causing disconnection. Hard to say which one exactly. Read the Network Configuration Guide and identify the offending device/software.

[suctionman]

Thanks for the response. I'm running Linux, and have no antivirus software. The only firewall is on my routers, and I've disabled all security measures on them. It now appears to successfully upload the file, but hangs on 100% with the message 'transferring' remaining. If I cancel the process queue, and then re-enable, the message log reads:

Error: Transfer aborted by user
Status: Starting upload of /home/tom/Desktop/4637
Status: Retrieving directory listing...
Status: ftpcontrolsocket.cpp(1707): Waiting for replies to skip before sending next command... caller=0x8da17d0

then continues to hang forever.

[botg]

Cause by some router or firewall between the client and the server that does not comply to the TCP specifications. According to the TCP specifications, connections are to be assumed alive and active unless explicitly closed. A lot of rogue routers and firewalls however just drop connections that appear idle.