Imagine a remote site - call it Dallas - with two WAN routers. Router WAN1 connects to the data center in Denver over a 1Gbps circuit and router WAN2 connects to the data center over another 1Gbps circuit. All the routers are participating in OSPF.
The Dallas site has network 172.25.0.0/16 and currently that gets advertised such that traffic to Dallas goes equally over WAN2 and WAN1. I would like a specific subnet say 172.25.200.0/23 to prefer ckt2 unless ckt2 goes down then it would use ckt1. What would I do in OSPF to color the route for 172.25.200.0 so that the data center prefers sending via ckt2?