Perhaps adding the external interfaces to the NAT section might help, in your case ETH04 and ETH05, that way your lan of ETH00 knows about the external interfaces? just a thought.
Routing and Bridging Firewall Solutions
Perhaps adding the external interfaces to the NAT section might help, in your case ETH04 and ETH05, that way your lan of ETH00 knows about the external interfaces? just a thought.