In my set up I have two Internet gateways belonging two different ISP's. One of the ISP's is located in U.S. and another ISP in located in India.
I have a L3 switch on which I have created different VLAN'S whose default route points to the Ethernet port of my router.
And on my core router we have a default route of 0.0.0.0 0.0.0.0 pointing to my one of ISP's in us as we have VPN links to U.S.
Suppose if I want to define another default (0.0.0.0 0.0.0.0) route on the core router to divert some of my VPN traffic and all of my Internet browsing traffic through the local ISP keeping the 0.0.0.0 0.0.0.0 which is defined for my U.S. ISP. How can I do it without defining BGP in the network?
If you want your routing to be based on protocols rather than destination address, i.e. you want VPN and HTTP traffic to take a different route than other traffic, you must use policy routing. A good book that detail policy based routing is, "Enhanced IP Services for CISCO Networks: A Practical Resource for Deploying Quality of Service, Security, IP Routing, and VPN Services," by Donald Lee.