FTP server problem
Hi - anyone got any bright ideas how to resolve an FTP problem?
We are moving server farms, and have migrated our (quite old) Serv-U FTP server from the old site, where it worked perfectly, to the new one. As far as we can see, it is configured correctly.
However, only some clients will connect. Or, rather, they connect but then log out.
Windows own FTP service and FileZilla, that I have tried, both connect perfectly and I can use the site. However, WS_FTP and Firefox's built in FTP service do not. I haven't attempted to diagnose the FF connection, but with WS_FTP I can connect and log in, and execute the FEAT command. But as soon as it gets the "203 OK to proceed message" and sends a CLNT command, Serv-U logs it out (at least, I think that it is at that end).
So why would it work for some clients but not others? Turning passive FTP on or off in the client end doesn't seem to make any difference.
As you have not changed the server I would be checking the firewall for issues. You should be able to view a log of the FTP connections on the firewall.
We did try that, but what I might now do is to look at the connections when using one of the clients that connects correctly and then compare it with connections with one of the clients that logs in and then quits, to see if we can spot what is going on.
OK, here's a solution!
It was hanging at the CLNT command. So for now, I have turned off the FEAT command in the client, and the connections are coming through OK.
But that isn't terribly ideal, and I have also discovered someone else having a similar problem with this (very old) version of Serv-U, so I am going to upgrade that as well and see what happens.
Now on to the other FTP problems on the server...*sigh*