Installing a Firewall (eg: Config Security Firewall/CSF) is one step to hardening security of your webserver. But this come with an issue that CSF block PureFTPd/ProFTPd server, so your FTP client cannot connect to FTP server with passive mode. This is because CSF block the passive connection ports. To enable it you need set the ip range for passive connection, and make sure you are not block it from CSF.To do that, you need to edit your FTP server configuration.For PureFTPd: open … Read more...