FTP Trubleshoot

1. Telnet IP 21
2. /etc/init.d/xinetd status or service xinetd status
3. lsof -i tcp:21 > check the port number output/input
4. proftpd works under xinetd service, check if ProFTPD works
5. cat /etc/xinetd.d/ftp_psa with following content:

#ATTENTION!
#
#DO NOT MODIFY THIS FILE BECAUSE IT WAS GENERATED AUTOMATICALLY,
#SO ALL YOUR CHANGES WILL BE LOST AFTER YOU UPGRADE PARALLELS PLESK PANEL.

service ftp
{
flags = IPv6
disable = no
socket_type = stream
protocol = tcp
wait = no
user = root
instances = UNLIMITED
server = /usr/sbin/in.proftpd
server_args = -c /etc/proftpd.conf
}

Enable Passive FTP:

1. Log in to your server via SSH as the root user.

2. Create the /etc/proftpd.d/55-passive-ports.conf file, add the following lines to it, and 3. then save the changes:

<Global>
PassivePorts 49152 65535
</Global>

4. Run the following command:

systemctl restart xinetd

Now your Plesk server accepts passive FTP connections. If you have installed the Plesk Firewall and switched on its default configuration, you need to add a firewall rule allowing passive FTP:

Direction: Incoming

Action: Allow

Ports: TCP 49152-65535

Sources: (any host)