I have a bit of a tricky setup that I want to achieve. We have 2 sites... at each site, we have a router connected to a BGP MPLS network (same MPLS network at each site). Between each site, we have a 1Gb connection. We also have a 4Mb connection.
Our IGP is OSPF. The routers connected to the MPLS network use BGP and redistribute routes into OSPF.
The setup I want to achieve is that for normal operation, traffic going out to the MPLS network should use the local MPLS router, and in case of a failure of the WAN link, it should use the 4Mb link (as opposed to the 1Gb link, which it would want to use). However, I want all OTHER traffic between the 2 sites to use the 1Gb link.
Is there a way I can advertise routes in one way to a neighbor, and a different way to another neighbor from the same router (eg can I advertise the routes with a massive cost to 1 neighbor, and the routes with a small cost to another neighbor).
I have attached a diagram that should show what I am trying to achieve.