OSPF Routes Missing After Configuration
advancedLAB TOPOLOGY
Multi-Area OSPF Lab
Area 0 backbone with four attached areas
Situation
R2 and R3 are directly connected on 172.16.29.4/30. R2 advertises the link in Area 0. R3 accidentally advertises the same link in Area 2. Remote routes never appear.
R2(config-router)# network 172.16.29.4 0.0.0.3 area 0
R3(config-router)# network 172.16.29.4 0.0.0.3 area 2
Your task
What should you verify first: routing table or neighbour state? What configuration mismatch prevents a healthy adjacency?
Reasoning
OSPF routers on the same link must agree on important adjacency parameters, including area. If the neighbour relationship is not healthy, expecting learned OSPF routes is premature.
Commands
R2# show ip ospf neighbor
R2# show ip ospf interface
R3# show ip ospf interface
Fix
Place the R3 backbone-facing network in Area 0, then verify the neighbour reaches FULL and only then check show ip route ospf.