CCNA: OSPF Passive Interfaces & Default Origination

Bundle lab · $29.99

Deploy OSPFv2 across a 3-router, 2-LAN branch/core/edge topology. Mark LAN-facing interfaces as passive so they do not send OSPF hellos or form adjacencies. Originate a default route only from the edge router and verify default propagation end-to-end using real client traffic. Includes realistic troubleshooting around missing adjacencies, non-propagating defaults, and unreachable external destinations.

Learning objectives

• Configure OSPFv2 on a 3-router branch-core-edge topology using assigned addresses
• Mark stub/LAN interfaces as passive to suppress OSPF hellos and adjacencies
• Originate a default route from the edge router into OSPF
• Verify OSPF neighbor adjacencies and learned default routes with end-to-end tests
• Troubleshoot non-forming adjacencies and missing default routes

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.