VRF Lite basics

[askbow]

Sometimes while you do routing, you want to do it in a destination-based way and also differentiate routing for different sub-autonomous systems in your AS. Well, such behavior can be enforced by PBR, but it is not that scalable and it lacks some of the nicer things dynamic routing protocols bring to the table. Enter Virtual Routing and Forwarding - VRF Lite (though, different vendors will call it differently) which can be seen as running different routing tables on one physical (or, well, virtual: CSR1000v) router.

http://askbow.com/2015/05/18/vrf-lite-basics/