Issue:
Implementing proftpd with TLS/SSL in zPanel with access issue through firewall.
Solution:
Besides port 21 for standard ftp and ftp with explicit SSL/TLS, need to forward range of port for Passive Mode.
Configuration:
- Centos 6.4
- zpanel 10.1.0
- proftpd 1.3.3g
Tricks:
Both the server firewall and the router port forwarding should be configured.