I've got a linux debian box (Eth 4 kernel 2.6) with Iptables to use as a router/firewall for my networks.

The configuration at this point:
Iptables ACCEPT all input/output/forward since it's just a testbox and i don't whant to lock my self out at this point.

1. DSL modem/router
external ip: 1.2.3.4
internal ip: 192.168.1.254
2. Linux router/firewall
ip(eth2): 192.168.1.68 / 255.255.255.0
ip(eth1): 10.0.0.254 / 255.0.0.0
ip(eth0): 192.168.0.254 / 255.255.255.0

on eth1 and eth2 are the internal networks of witch eth1 is private network and eth0 is the public network.

At this point i got internet (NAT) on eth1 and eth0 so internet works on both internet networks. But i can't get port forwarding to work from eth2 to eth1 to 10.0.0.1

I've searched this forum at first, but none of the solutions i've found seem to work. I've seen a lot of PREROUTING rules, but i can't seem to get them working in any way.

I just need a working example for my (until now) simple setup. I would like to forward port 8080 to 10.0.0.1 on eth1.

Would there be someone so kind to help me out here, i'm lost at this point.

Oke, i've got it working now. I forgot the postrouting. But now when i set FORWARD in the 'filter chain' the connection fails again.

Is there someone who can help me with this?

Before we can help, could you post your iptables script, once we see what you have, we can then help to troubleshoot it.