Iptables & port forwarding

[Nathan Cable]

I have the following rules in my IP tables setup that should work for port
forwarding:

-A PREROUTING -p tcp -m tcp -d 216.232.115.208 --dport 81 -j DNAT
--to-destination 192.168.1.10:80

-A FORWARD -p tcp -m tcp -m state -i eth2 -o eth0 --dport 81 --state
NEW,RELATED,ESTABLISHED -j ACCEPT

This should have my gateway server accept incoming connections and redirect
them to an internal web server. However, it doesn't work! Our server is
already masquerading for our LAN, and I have a couple of other rules that
work just fine. Any ideas why this setup doesn't work? I have tested it on
two different Linux boxes with the same result.

I'm using Redhat 7.2 with iptables 1.2.5-3.

Thanks,

Nathan