OSPF Multi-Area: ABR Area Mismatch and Route Repair

Bundle lab · $29.99

Build and troubleshoot a compact multi-area OSPF design with a single ABR between area 0 and area 10. You will deploy OSPF, observe an adjacency failure caused by an area mismatch on one transit link, repair it, and validate that routes propagate end to end between two user LANs.

Learning objectives

• Implement OSPF on a multi-area topology with a correct ABR.
• Detect adjacency and routing failures caused by OSPF area mismatches.
• Restore stable routing adjacencies and inter-area route exchange.
• Validate OSPF neighbor state and route propagation end to end.

Troubleshooting focus

• Verify every link's interface status and IP addressing (`show ip interface brief`) and correct any interface that is down or misaddressed.
• Confirm each device's running configuration matches the lab objective, and bring any interface, route, or service that is not in its expected state back to health.
• Trace end-to-end reachability with ping/traceroute and isolate the first hop where forwarding fails.