iptables masq eth0,1,2,3
 

have a problem on one linux box with 4 nics runnin iptables on two different subnets. Here's my layout:

eth0: 1.2.3.4
eth1: 192.168.1.1

eth2: 2.3.4.5
eth3: 192.168.2.1

masq'ing eth1 through eth0 works great, however no traffic is masq'd from eth3 through eth2. I can ping eth3 boxes from eth2, however no eth3 box gets out. This may have something to do with the default gateway on my box, but I dont know. My Q is, how do I get eth3 + eth2 runnin the same as eth1 + eth0 ? do I somehow need to route eth3 through eth0 ?