Hi, An strange, for me, situation... I can connect to my server using sftp. I can also connect using FTP in active mode, with a plain authentication (insecure, just for test). But I can not connect if I use passive mode, doesn't matter if using plain or TLS. I can also NOT connect using active mode and TLS authentication... Have you any idea about where could be the problem? My system is Debian 9 + ispconfig 3 + apache2 (perfect server guide). In an old system, using debian 7 + ispconfig3 I can connext FTP using TLS and default passive mode.
It might be that the passive port range is blocked. Define the passive port range in pure-ftpd and then ensure that the same port range is open in your firewall.
you can fix that by defining an active port range in your client, and opening that in your firewall(s) and port forwarding that range in your nat. Or just use passive mode once you set that up.
