Ok, so here is my scenario. eth0 and eth3 point to 2 different ISPs, eth1 is an internal network say on 220.127.116.11 and eth2 is on another network say 10.1.1.0.
I want each network to be on their own internet connection.
I'm using IPtables to route eth1 to eth0 and eth2 to eth3 so each network has a physical connection to their own internet. The problem is routing. I can't assign 2 default gateways.. one to eth0 and one to eth3. Right now I only have a default gateway on eth0. My 18.104.22.168 network has internet access, eth1 talks to eth0 which has a default gateway to the internet. My 10.1.1.0 network does not have internet, eth2 is either talking to eth3 which has no default gateway OR eth2 is trying to talk to eth0 which is forbidden by my iptables. How can I go about adding 2 default gateways or go about solving this problem?