CCNA Foundations: OSPF Day 8 — OSPF Troubleshooting Capstone

Today's daily lab

Advanced CCNA OSPF troubleshooting capstone on Cisco Modeling Labs (CML-Free). A three-router, two-host enterprise-style topology is pre-broken with multiple independent OSPF faults. Your job: diagnose and fix them so adjacencies form across areas and the end hosts can reach each other. The final solution forwards end-to-end and adheres to clean OSPF hygiene.

Learning objectives

• Diagnose and repair OSPF adjacency failures due to area mismatches and interface timer mismatches
• Identify and correct incorrect OSPF network statements and wildcard masks
• Implement OSPF hygiene: explicit router-ids, passive-interface default with selective exceptions, and advertising loopbacks
• Verify OSPF neighbor states, LSDB synchronization, and end-to-end reachability from hosts

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.