Cannot connect to FTP - External Firewall

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This a new out of the box install of Plesk 12.5 on 1&1 Could Server.
The FTP would not list directories and it will time out in the process of retrieving directories. After opening some ports on the server firewall, I am able to get the initial list of directories, but I cannot switch directories without timing out. Testing with Firefox's FTP client I noticed that it was asking for username and password for each directory change, something i could not see when using FileZilla.

Plesk Firewall is not installed, the could server has its own firewall and I opened the following ports:
TCP: 20, 21, 22, 80, 443, 3306, 8443, 8447, 49152-65534 (after reading this article: http://kb.odin.com/en/119525)

Any idea what the issue is?

 

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The /etc/proftpd.d/passive_ports.conf lists PassivePorts 30000 30400. Once added to the external firewall the issue was resolved.
This issue was escalated twice to Odin support by my host and they did not come up with the solution, blaming it on my FileZilla client. Strange, but hopefully this will help the next person.

New firewall ports: TCP: 20, 21, 22, 80, 443, 3306, 8443, 8447, 30000-30400, 49152-65534