LinuxQuestions.org - [SOLVED] Port Forwarding to Debian box

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Port Forwarding to Debian box

I have been trying to get Port Forwarding working to my Debian Lenny Server.

At first I had a D-Link modem router which I set to forward ports 80,443, and 22 to the Debian Box.

screenshot:

However, when I accessed the network (through dyndns), I just got the modem's web admin screen.

I replaced the modem with a mega 105WR modem, but the result is the same.

So I started to think it may be the Debian Box. However, it would appear that the Firewall is turned off.

Code:

 iptables -S

-P INPUT ACCEPT

-P FORWARD ACCEPT

-P OUTPUT ACCEPT

Can anyone think of something I can look at?

I'm seriously confused.

Weirdness!

Sitting on the network, any attempt to access the server through the internet (through Dyndns) results in a connection to the modem's web admin page.

If I leave the office and go through the dyndns site externally, I access the server as expected.

It would seem that the modem recieves a request for it's own IP from inside the network and, rather than forwarding the ports to the server, intercepts them and serves up it's own pages.

If it receives a request from outside the network, it forwards on to the server as expected.

Does this behaviour sound typical? Or is it just our backwards South African Proxy-based system?