IntermediateUnlock
OSPFv2 Multi-Area with ABR Summarization (Redundant Core)
Deploy a 5-node OSPFv2 lab featuring a redundant area 0 triangle (R1–R2–R3) and an ABR (R3) connecting to area 1 with branch networks on R4. A client on R1’s area 0 LAN validates reachability to branch loopback networks summarized by the ABR. You will set explicit router-ids from Loopback0, use passive-interface default, advertise R4’s loopbacks as /24s using ip ospf network point-to-point, and summarize area 1 into a /23 on the ABR. Verify FULL adjacencies, a single O IA summary on R1, and end-to-end connectivity. Troubleshoot an introduced area mismatch and interface/addressing issues.