every of my branch office routers (many hundred routers) is connected over its own vlan to our central site (we bought a metro ethernet cloud).
At the central site there are two bigger routers talking ospf with all the branch office routers. So they have many hundred vlans/sub-interfaces with LLQ-staff defined.
I now want that every traffic of one branch office goes all the time over the same central router and vice versa but another branch office should use the other central router in normal situation (for load balancing between the central routers). In case one central router dies all traffic should go through the remaining central router.
How should I configure the ospf routers so that the traffic from the branch router goes over its preferred central router?
I would like a solution by which only manipulating the central router configuration allows moving the traffic of one or more branch offices to the other central router but this is no absolute need.
What would you suggest the best solution?