WindowsUpdates Arrrrgh!

September 30, 2005 7:17 AM

WindowsXP and FTP Filter: I am running WindowsXP Pro and every time I allow it to update, my FTP client fails. I have tried everything I can think of and all Microsoft's advice, to no avail. Anyone seen this before?

I use CuteFTP, but the FTP client within Internet Explorer fails as well, so I know it is not CuteFTP itself. I can FTP very small files, but anything larger than around 1KB fails and leaves a 0 byte file on the server I was moving the file to. I assume the small files work because they can be sent in one chunk and require no feedback from the remote server to finish, but I am just guessing about that. I have tired enabling an exception in the Windows Firewall, tried opening port 21 in Windows Firewall and tried completely turning off Windows Firewall and had no luck. Microsoft's troubleshooting goes no further than this. I end up having to roll back the updates and everything is fine again, but I am living without critical updates at the moment and that makes me nervous. My Google-fu turns up nothing about anyone having similar problems. Any pointers, anyone?

posted by juggler to computers & internet (6 comments total)

juggler, I work for MSFT. Contact me via email (look at my profile), and I will hook you up.
posted by stupidcomputernickname at 7:33 AM on September 30, 2005

I had a very similar problem which turned out to be a firewall issue.

I'm clueless how it was actually fixed though. Sorry :(
posted by lemonfridge at 9:39 AM on September 30, 2005

I have the 'exact' same problem.

If there is a solution, please post it here.
posted by Argyle at 12:16 PM on September 30, 2005

Just guessing here, but are you behind a NAT gateway? Your problem could be related to that.
posted by Goblindegook at 4:03 PM on September 30, 2005

Are you using active or passive mode?

What ftp daemon is the server running? Does it only fail with one server or does it fail universally?

Do you use PPPoE or anything else that would result in a smaller MTU? Do you have Path MTU discovery enabled? Are you blocking ICMP "fragmentation needed" packets in your firewall?
posted by Rhomboid at 6:34 PM on September 30, 2005

I fixed my problem by upgrading the firmware in my Linksys router. I only wish I would have realized where the problem lay earlier.
posted by Argyle at 10:59 PM on October 8, 2005