Routing

I have a linux router with 2 external and 2 internal ports.

Each port needs to route traffic to one of the internal ports, and the internal traffic between the 2 internal ports should not go out the external ports.

The IPS on the internal networks are global. ie. no NAT required.

I think what I need is this..

$ext_net1 = external nework IP/MASK 1
$EXT_IP1 = ip of external interface 1
$ext_net2 = external nework IP/MASK 2
$EXT_IP2 = ip of external interface 2
$int_net1 = internal network IP/MASK 1
$int_net2 = internal network IP/MASK 2

ip route add $ext_net1 dev eth0 src $EXT_IP1 table 1
ip route add default via $ext1_gw table 1
ip route add $int_net1 dev eth1

ip route add $ext_net2 dev eth2 src $EXT_IP2 table 2
ip route add default via $ext2_gw table 2
ip route add $int_net1 dev eth3

ip rule add from $int_net1 table 1
ip rule add from $int_net2 table 2