I currently have a linux machine with a perm modem connection to the net. I'm using iptables to port forward from this machine to other machines in my private network. All is working fine.
I've now just installed ADSL in bridged mode and want to do exactly the same thing. I've installed the ADSL modem on a second ethernet card in the linux machine, and it's talking to the net fine. When I setup port forwarding for the IP address of the ADSL connection, it doesn't work. For example, if I don't have any iptables rules, I can telnet to the IP address of the ADSL connection and get to the linux machine fine. If I add a port forward rule for telnet to another host, when I try and telnet to it from the net, it just says "trying" and doesn't go anywhere. Both connections have static IP's, and I disconnected the modem link and flushed the iptables rules before trying it with the ADSL link. I used the following line to do the port forwarding - works fine on the modem link, but doesn't work on the adsl link - can anyone tell me why? (obviously x.x.x.x was substituted with the appropriate connection IP address) -A PREROUTING -d x.x.x.x -p tcp -m tcp --dport 23 -j DNAT --to-destination 10.20.0.1:23 Thanks
