1) Primary area border router (in area 0 AND NSSA area 50)
2) Primary link from #1 to #4 is a P2P pair of radios
3) Secondary link from #1 to #4 is another P2P pair of radios
4) Leaf router in NSSA area 50
So there are TWO separate OSPF sessions, one over each P2P radio link.
OSPF cost is set so the primary link is preferred.
All works well. If secondary link drops, things still work well.
If primary link drops, hwoever, the OSPF link-state database gets confused. It thinks that the primary link is STILL UP (because the ethernet interfaces to the local P2P radios ARE still up) even though the OSPF session drops (dead timer expires).
QUESTION: How do I avoid this? How can I convince the OSPF process that the link state should be updated to match the OSPF session state over the primary link?
I do NOT want to use scripting to monitor (via ping) and drop the interface states. I know I can do that. But that has drawbacks too (like having to periodically re-enable the interface to test the P2P radio link state--unless I use the backup link to communicate and tell the far side to disable/enable the interface there).