I have two gateways doing exactly the same thing - any one of them can be termed as default gateway, But now you want to split the traffic and do many more smarter things on the traffic! you want to control exactly what kind of traffic goes through which Gateway?
Install Linux! I do not have special atttraction towards Linux, but Linux networking tool excel in many areas and much better than what plain vanilla windows installation give you. So thats why linux. Actually - I can assign hosts in dhcp for static routes, implement rip or igrp in my firewalls - but all that costs alot of stupid network traffic. Does not make sense to me. You are welcome to accept this solution - or - you can put your comments right here and I will get enlightened with your smart solution. Any way, lets continue with our problem.
so what I did, I put another Linux Box, which decides where to send packet, logs the packet, creates the graph of which protocol being used most, how much vpn traffic, how much non - vpn traffic and its all fast, because my firewall runs on PII cpu and My Linux box runs on PIII with minimal services. And gives me alot of flexibilities.
how to do this?
- install 2 network interface cards
- learn how to use "ip" command
- add rules and tables on ip command
- tell ip command to send which traffic where based on packet source, packet destination and user id
- and even you can control that which mac address can get how much bandwidth(i have not done yet, but you should go and read LARTC - Linux Advanced Routing and Traffic Control)
- install transparent proxy
- install iptraf + rrd tool