FTP Server Stops allowing Logins

[Patrickm]

I have a win2k3 server running a an FTP site for one user (anonymous). We
use it to transfer files from an AS400 to ur Windows Network. This has run
fine fine for the last year, now all of of a sudden it bombs out and stops
allowing user(s) to log in. The service is still running, just nobody can
log in. If I Restart the IIS admin Service it runs fine for a random limited
amount of time. There is absolutly nothing in any of the event logs
indicating a problem, nothing in any of the IIS logs either. Any ideas?

 

[Charlie Tame]

Just an idea. Could something at the other end have changed to the "Passive"
setting, if so it is possible that a firewall somewhere is causing trouble.

http://www.slacksite.com/ftp.html

Since random (ish) ports are used maybe something is already using a port
that's chosen causing a conflict, so the FTP server isn't seeing the
connection?

The login failure messages I find a bit deceptive, this site may also be
helpful...

http://www.mvps.org/marksxp/WindowsXP/IIS/iis1.php

And this

http://www.mvps.org/marksxp/WindowsXP/IIS/iis1.php

Sorry I don't have a nice "Theory" but perhaps there's something like a clue
in that lot?

Charlie