Question The server is blocking my iP when uploading via FTP

[quattro123]

Server operating system version

Debian 11

Plesk version and microupdate number

18.0.55

I realized, that Plesk is blocking my own IP when I upload many files via FTP (Filezilla).

First, I thought it is fail2ban, but somehow it only works again, when I deactivate the plesk firewall.

Any idea what could cause this behaviour or where I could start to check?


Greetings

 

[Kaspar]

IP addresses that get banned by fail2ban are blocked by the same Firewall mechanism (iptables) used by the Plesk Firewall. Deactivating the Plesk firewall clears all bans. So it is still possible (likely even) that the issue is caused by fail2ban.

Did you whitelist your own IP address in fail2ban?

 

[quattro123]

Fail2Ban was deactivated the whole day now. I couldnt even login via FTP, getting "timeout" error.
When turning the firewall of again, its working.
Turning it on, it immedately stops working.
Turning it off again, makes things work again.

 

[Kaspar]

Check if firewalld is also running on your server by running # systemctl status firewalld. If it's not running or not installed, can you post the output of iptables -L INPUT, when having the Plesk firewall enabled and you can't access your server via FTP?

 

[quattro123]

firewalld seems to be inactive.
I will check your second advice tonight.

 

[quattro123]

Right now I can not connect to the FTP server again.

Here is the output of iptables -L INPUT

 

[Peter Debik]

When do you get the "timeout" exactly. Is this really before login takes place or is it when trying to list directories after a successful login? Could you please provide the log from your FTP client? In most clients such as Filezilla this can be seen and copied easily from your client's user surface.