I have a Lab Scenario as follows:
Two routers R2 & R4 are connected to a F/R cloud via Area 246. They are also connected to each other via Ethernet in Area 0. I have two loopbacks configured on R2 (184.108.40.206) and on R4 (220.127.116.11) in area 246 also.
The cost of reaching network 18.104.22.168 from R2 is therefore 10 + 1 (loopback) via Ethernet or 64 + 1 via F/R Serial link. When I bring the routers up from a cold start the preferred route is via the F/R link even though the cost is higher. Is this because OSPF prefers the inter-area route over the Intra-area route ?
If I shut R2's serial interface the route to 22.214.171.124 becomes IA over the Ethernet with cost 11 as expected. However, as I open the Serial interface the route to 126.96.36.199 is still over Ethernet and the F/R link isn't used ?
Can anyone help to explain ?