I am trying to get my fedora core 2 linux box to route from a ADSL modem that has 2 IP's (dynamical ip's, but only when i cut power to my modem).

My network:
I have a motorola modem in my basement and a linux box that has 2 NIC's, eth0 goes in to the modem and eth1 goes in to a 24 port Ruby tech switch and then out to the computers in my house (about 6 or something like that). Right now i have a router betwine my modem and my linux box because i had to seek help on google, but that has to go.

The Problem:
I have tryed to get the box to route and have sat DHCP up on it. The computer that goes in the switch rigth now can get a IP, netmask, gateway, nameserver ect. but i can't ping the address that eth1 has and i can't get internet on it (it is a Win XP computer). I messed with my IPtable, but i can't get the data from eth0 to flow to eth1 and then to my XP computer.

Everytime i try to change the eth1 ip from to and it works, but ever time i reboot is goes back to how can i force it to have the ip

I have tryed all the guides on the net i could find, but it still does'nt work.

Thanks in advance