There are two modes for connecting to an FTP server - active and passive.
Active mode is intended for connecting through a firewall. If you work with the Internet through a home local network or through an enterprise local network, your administrators probably use some kind of firewall to protect the network.
When working via FTP through a firewall, you may receive an error like “425 Can't build data connection: Connection refused” or similar.
This means that you need to change the settings of your FTP program so that it forces it to use passive FTP mode to connect to our server.
Above in this document, when setting up the FTP program Far Manager.
