[CentOS] Can't get forwarding to work

Hello all:

I am having trouble getting port forwarding with iptables to work.

I have this configuration:

Internet --- Linux machine --- Windows machine

The windows machine is set up to listen on IP address 10.0.0.31

I am able to use lynx to connect to http://10.0.0.31 on the linux machine so there is no problem going from the linux machine to the windows machine.

I have tied a public IP address a.b.c.d to the linux machine and entered these rules in its firewall:

/sbin/ifconfig eth0:1 $WIN_EXTERNAL_IP netmask $ETH0_NETMASK broadcast $ETH0_BCAST /sbin/iptables -t nat -A PREROUTING -p tcp -i eth0 -d $WIN_EXTERNAL_IP --dport 80 -j DNAT --to $WIN_INTERNAL_IP:80 /sbin/iptables -A FORWARD -p tcp -i eth0 -d $WIN_INTERNAL_IP --dport 80 -j ACCEPT

I have this log entry at the bottom of the firewall rules:

/sbin/iptables -A FORWARD -j LOG --log-prefix "FORWARD "

When I try to go to the external IP address http://a.b.c.d from another network, I get an error.

Any ideas?

Thanks, Neil

-- Neil Aggarwal, (281)846-8957, www.JAMMConsulting.com Will your e-commerce site go offline if you have a DB server failure, fiber cut, flood, fire, or other disaster? If so, ask about our geographically redundant database system.