OSPFv2 Multi-Area with ABR Summarization (Redundant Core)

Bundle lab · $29.99

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.

Learning objectives

• Build an OSPFv2 multi-area design with a redundant area 0 triangle and an ABR to area 1
• Set and advertise explicit OSPF router-ids from Loopback0
• Use passive-interface default and selectively enable OSPF on transit links only
• Advertise /24 loopbacks using ip ospf network point-to-point semantics
• Summarize area 1 networks with area range and validate a single O IA summary in area 0
• Verify adjacencies, LSA types, and route tables; test redundancy and failover
• Troubleshoot area mismatches, neighbor states, and route propagation issues

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.