We currently have 6 sites in hub-spoke topology, with FR for primary connection on primary router and ISDN for backup link on secondary router at each site. The network will change the primary network to fully-meshed MAN, and the secondary network will be DSL point-to-point connections (extended star topology). I would like to have:
1. every router in primary network act as gateway for its peers, to pass on all its WAN routes to other sites;
2. secondary network is passive under normal circumstance;
3. if all connections in primary network for one site went down, then the secondary router at that site will become active and automatically pass the routes to that primary router.
Is it achievable? Is there any examples available that I could have a look?