Cannot Connect to CVS Service Externally(connection refused)

I'm sure some variation of this question exists in some form or another. I've been looking everywhere, and I just can't seem to get this problem resolved.

I'm still pretty new to linux.

Anyway, I have installed the mandrake 10 distribution and have setup and installed cvs running on port 2401. The cvs server works great from my lan. I can access from both my linux machine and my windows laptop using the private static ip address assigned to my linux machine.

However, when I attempt to access the server using the wan ip, it says "connection refused." I have port 2401 forwarded on my router and "canyouseeme.org" claims to see the service.

I really believe it to be some setting in the OS, but I can't figure it out for the life of me.

I've run out of things to try. Any ideas?

I was playing around a little bit more with my router configuration and I figured I'd try setting the router to dmz again.

Interestly enough, this time when I tried to connect, it gave me a "timeout" error instead of "refused."

I'm thinking that maybe my problem is two fold. Perhaps, the port forwarding is not working as it should be in addition to a software firewall blocking my connection attempts.

To the best of my knowledge, I have disabled the firewall and set the default security setting to "poor" (not sure if that makes any difference, but I'll try anything at this point). I also temporarily disabled iptables (again, to the best of my knowledge this was done correctly). When I ran "iptables -L" as root, only the 3 headings came up.

Is there possibly something I have done wrong? Or some other firewall I have overlooked? Does cvs need to be configured differently if external connections are necessary?