I have a 5400R acting as my core switch. All of my devices at this location are using it as their default route.
I have two edge routers attached to it each going to sepreate ISPs.
Each edge routers has a static route:
Primary Edge Router 10.0.0.1
route: 0.0.0.0 0.0.0.0 208.x.x.x.x (ISP1)
Secondary Edge Rotuer 10.0.0.5
route: 0.0.0.0 0.0.0.0 12.y.y.y (ISP2)
Core Router 10.2.2.1
route 0.0.0.0 0.0.0.0 10.0.0.1
Router Diagram
each router is also advertising it's direct /29 connection to each ISP via OSPF to the core.
currently if one if the ISPs is down i have to manually change the static route in the core to point to the other router. I'm sures there is a better (automatic) way of switching between edge routers but haven't been able to figure it out yet.