I have a setup where I use a Linux box with netfilter to forward tcp connections between a "client" and a "server.
The Linux box has a default gateway defined. However, there are
multiple other routers on the same network, and the default
gateway router sends ICMP redirects to inform the Linux box which router should be used to reach some destination.
Probably a stupid question. But. Why don't you simply define two static routes on the NAT box pointing to firewall (packets to server) and routerC (packets to client)? Or let the router do its job of actually routing packets instead of generating error messages back to clients (in which case you would really need one router with 5 interfaces).
IMHO, relying on ICMP redirects to create routes for you is inefficient and error prone. It's kind of asking for trouble.
-- Aleksandar Milivojevic <amilivojevic@xxxxxx> Pollard Banknote Limited Systems Administrator 1499 Buffalo Place Tel: (204) 474-2323 ext 276 Winnipeg, MB R3T 1L7
