How to configure PASV mode for Gene6 FTP Server:

Step 1.

First, highlight your desired domain under, "Domains" on the left side of the screen.

Then double click on "properties" on the right side of the screen.

Under, "Domain settings", click on, "IP binding".
You should now be seeing the "IP binding" tab. Under
"Redirect PASV IP", put your desired domain name or enter your
OUTSIDE IP ADDRESS (You can find out what it is by going to
http://www.whatismyip.com).If you are running a webserver and
DNS server, you cannot put the name of your FTP server, for example,
"ftp.yoursite.com", you still have to enter your OUTSIDE IP ADDRESS.
If you have a dynamic IP and are using a
dynamic IP service such as "no-ip.com",
you can enter your dynamic DNS server website address
(You can get one at no-ip.com) for example,
"yourname.no-ip.org", or "yourname.dyndns.org".

Step 2. On the bottom, under "Passive Port Range", enter 50000 on the
left window, and 50100 on the right window, and click OK.