I have a Ubuntu server hosting client websites, IP:
220.127.116.11. We have Pro-FTPd set up and it runs fine when connecting through FileZilla to upload files etc. We have some clients with software that automates some file uploading so I have set up FTP accounts for each of them (actually standard user accounts in Linux, but the FTP uses them the same).
Most can connect fine but one client cannot, they get a "connection closed by host" error. They also noted that they cannot connect via Windows Explorer, which I tested and it doesn't work for me either. I get a message:
Windows cannot access this folder. Make sure you typed the file name correctly and that you have permission to access the folder.
Details: The FTP session was terminated
(I tried another server from Explorer and it connected fine so it's not WE itself.)
We have a basic iptables firewall on the server but nothing else AFAIK. iptables is not blocking anything specific.
I also checked log files and could not see the client server's IP address anywhere (ran
grep in the entirety of
var/logs). The client has also tried disabling firewalls etc their side with no luck.
Is this likely to be a problem on our side? Is there anything I can do to diagnose the issue?