[Nottingham] Port forwarding with iptables

[Steve Goodliff]

Hello All,

Please can anyone help me out with my latest linux networking conundrum.

I have a redhat 8.0 machine with 3 NIC's. 2 of them are connected to ADSL
routers and the 3rd to our internal network.

Both routers have web front ends which I would like to access by connecting
to the redhat box and then move onto some sort of balancing traffic across
the 2.

Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use
Iface
192.168.1.0     0.0.0.0         255.255.255.0   U     0      0        0 eth2
192.168.254.0   0.0.0.0         255.255.255.0   U     0      0        0 eth0
10.0.0.0        0.0.0.0         255.0.0.0       U     0      0        0 eth1
127.0.0.0       0.0.0.0         255.0.0.0       U     0      0        0 lo
0.0.0.0         192.168.254.254 0.0.0.0         UG    0      0        0 eth0

The redhat box has the ip address of 10.1.1.2. I've tried the Port
forwarding stuff off the netfilter howto but can't get it working. The
machine also runs NAT for the clients on the 10.x network.

iptables -t nat -A PREROUTING -p tcp --dport 8080  -d 10.1.1.2 -j
DNAT --to-destination 192.168.1.1:80

I've tried setting the FORWARD policy set to ACCEPT but that doesn't help
matters.

Any suggestions would be much welcome.

Steve G