I have multiple NICs on a RHEL 5.1 system. I want to force all port 80/443 traffic through eth1 and leave the remaining routes as is. I am really not sure how to go about doing this. I have 4 nics on 4 different vlans.

route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
172.20.21.0 * 255.255.255.0 U 0 0 0 eth2
192.168.21.0 * 255.255.255.0 U 0 0 0 eth1
172.20.20.0 * 255.255.255.0 U 0 0 0 eth3
192.168.20.0 * 255.255.255.0 U 0 0 0 eth0
169.254.0.0 * 255.255.0.0 U 0 0 0 eth3
default 192.168.20.3 0.0.0.0 UG 0 0 0 eth0

I can't change the default gateway, so I am not sure what would be better, IPtables or another avenue? If I am not clear please let me know since I am not totally sure what I am asking.

Thanks

Inbound or outbound?

Sorry I didn't include that, outbound. I am trying ultimately to be able to do the RHN updates.

What you probably want is port-based routing with iproute2. (This is non-trivial to set up for a newbie.) Cruise the 'net for some information, and post back with progress/questions. I don't have time to set up a test case at the moment.

I was able to actually resolve it by creating a route in the routing table straight to the RHN which is all I needed. I appreciate all your help though! I had no idea I could do routes outside of my internal NIC routes. Always love learning something new

Thanks again!