I'm trying to configure IIS 7.5 FTP service on a network that is hidden behind a firewall / NAT. The communication should look like this:
client (FileZilla) <--> router (NAT, firewall) <--> Win2008r2 (IIS + FTP)
As I understand it I should aim for passive connection - or at least that is what FileZilla or Total Commander use automatically.
I can now successfully log in to my FTP server given an IIS Manager user that I've configured, however, I can't work with the data, e.g. the
LIST command will fail with "connection timed out, failed to retrieve directory listing" etc. I think I have incorrectly configured ports and that's where I need help.
In FTP 7.5, you can go to server > FTP Firewall Support > Data Channel Port Range. It is
0-0 by default and in this documentation page, a range of
49152 - 65535 is given as an example.
So I tried it and on my router, I've created a new port forwarding rule like this:
"if external port is 49152 - 65535, forward to MYWEBSERVER 49152 - 65535"
However, with these settings in place I immediately lost internet connection on all other devices on the network. I'm not a network expert and it may be obvious to you that I made a mistake, however, what port range should I configure on my IIS / FTP and on my router so that there is no chance that it will conflict with other connections from other devices?