rohnlawadmin
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Users Cannot Connect to FTP Server
Hosting an FTP server on a Windows 2K8 machine. Previously worked fine until the last week or so - no known changes to the server. Firewall is verified with port 21 open for FTP services and I double-checked permissions on both the share and the directory security itself. Outside users get the prompt for user credentials but even after seemingly accepting the login info, it just shows a progress bar at the bottom of IE that never connects. I can even see the incoming connection in the firewall so I know they get that far. Tried restarting the FTP service and the entire server and I still get the same result. Not sure what else to troubleshoot but I need to get it fixed ASAP. Thanks!
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AlexPace
If you are prompted to give credentials but can't get past that point then most likely the browser is requesting a directory listing but can't open the data channel to transfer it.
ASKER
How do I correct that and also why would it happen if I made no changes on my end?
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ASKER
Interestingly enough, when I installed CuteFTP from two different remote locations, it connected to our FTP site with no problem whatsoever. I can't get it to connect outside of that software though and we had users who regularly connected with IE, Mozilla and on Mac computers. I guess I can tell all the remote people to install and use this software but I'd really like to not have to do that since it was easier just letting them access through a browser. I know in the past I had to make sure the passive FTP checkbox in Internet Options was unchecked but that isn't the issue this time because I've verified it is turned off (the setting is is supposed to be for our server).
I bet CuteFTP can make a log so why don't you see if it is sending PORT or PASV to open the data channel.... then you'll know which type actually works. Also, check your server logs to make sure these are the last commands sent from the cleints that DONT work.
ASKER
I just tried again via IE and now it is working. I didn't do anything on the server end though. Any idea what would make this happen?
The port range used for the data channel may be partially blocked. The software tends to increment through the range so maybe you just hit a few blocked ports. More likely is that someone is tweaking your firewall rules, either at your office or at your ISP.
Check the server logs to compare the PASV or PORT commands sent when it failed vs. when it worked. You should be able to just search the raw command trace for the string "PASV" or "PORT"
ASKER
I am the only one with access to change anything in the office so maybe it is our ISP. I'll review the server logs when I get time to see what may be the cause but at least I know what to look for. Thanks!