I have a scenario with a FC2 machine with 4 NICs in it. The networks are setup like this:

ETH0 - IP: 192.168.168.1
ETH1 - IP: DHCP via cable modem
ETH2 - IP: DHCP via cable modem
ETH3 - IP: DHCP via cable modem

I have an iptables script setup so that certain internal IPs are routed through eth1 or eth2 and then all the rest are dumped to eth3. I have done this before in the past and didn't have to modify my route tables, but I think that something was setup with them that I didn't do myself. My current route tables look like this:

Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.168.0 * 255.255.255.0 U 0 0 0 eth0
zz.yyy.xxx.0 * 255.255.248.0 U 0 0 0 eth1
zz.yyy.xxx.0 * 255.255.248.0 U 0 0 0 eth2
zz.yyy.xxx.0 * 255.255.248.0 U 0 0 0 eth3
169.254.0.0 * 255.255.0.0 U 0 0 0 eth3
127.0.0.0 * 255.0.0.0 U 0 0 0 lo
default 1.xxx.yyyy.zz.cf 0.0.0.0 UG 0 0 0 eth1
default 192.168.168.1 0.0.0.0 UG 0 0 0 eth0

I think I need another route to make the internet work on the other two NICs eth2 and eth3. I tried to add additional default routes but that caused everything to stop working.

I can't seem to find anything on the internet that talks about a setup like this. I am not sure how it worked before but I know it can be done. Thanks in advance.