CCNA OSPF Day 7: Passive Interfaces + Default Origination

Today's daily lab

Deploy OSPFv2 across a small branch-to-edge topology, mark user-LAN interfaces passive, and originate a default route at the edge so branch hosts learn O*E2 and can reach an internet-facing host. You will implement, verify, and troubleshoot OSPF passive interfaces and default-information originate.

Learning objectives

• Configure OSPFv2 with explicit router-ids and correct network statements on all routers
• Apply passive-interface default and selectively unpassive only transit interfaces
• Originate a default route into OSPF (E2) from the edge router using default-information originate
• Verify end-to-end connectivity from the branch host to an internet-facing host and interpret OSPF route types
• Use show/troubleshooting commands to confirm neighbors, LSAs, and routing tables

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.