I am having issues with the Windows ftp client over openvpn. The ftp client can make a connection to the ftp server but cannot initialize the data connection. I have port 20 open in the firewall. I have used passive mode in the ftp client. The ftp client is proven to be working fine when the host is on the LAN or using an external address to connect. Only the data connection over openvpn does not work.
I remember seeing ports in the 40000-60000 range used for the data connection from watching traffic analyzers... I do not have these ports open in the firewall. I'm thinking this is my issue but i'm not sure how to fix it.
The ftp client is Windows Xp/vista (multiple machines have been tried)
The firewall and openvpn are running on Red Hat Enterprise Linux 5.4