Question

A network engineer is troubleshooting an OSPF design where Area 20 is connected to Area 0 only through a transit Area 10 (Area 20 has no direct link to the backbone). Routers in Area 0 can reach networks inside Area 10, but they are not receiving any inter-area (O IA) routes for prefixes originating in Area 20. The ABRs are fully adjacent within their respective areas, and all interfaces are in the correct areas. Which action correctly restores end-to-end reachability to Area 20 prefixes?

Accepted Answer

Configure an OSPF virtual link across transit Area 10 between the Area 0/Area 10 ABR and the Area 10/Area 20 ABR using their router IDs

Answer

Configure Area 20 as a totally stubby area on both ABRs so the backbone can summarize its prefixes

Answer

Increase the OSPF reference bandwidth on all ABRs so the inter-area metric is recalculated

Answer

Enable OSPF authentication in Area 0 to allow the Area 20 ABR to inject Type 3 LSAs into the backbone