Question 150 A remote OSPF stub area has no external LSAs and operators call that a failure even though an ABR supplies a default route. Which technical mechanism best explains the behavior observed in this scenario? OSPF election and adjacency expectations depend on network type; an unsuitable DR location can break multiaccess operation. A stub area's design suppresses Type-5 external advertisements while its ABR can provide a default route. OSPF identifies routers by 32-bit router IDs; duplicate or unexpected IDs disrupt LSDB and adjacency assumptions. OSPF INIT means hellos are received but two-way recognition is not yet confirmed in the neighbor lists. ExplanationCorrect Answer B:A stub area's design suppresses Type-5 external advertisements while its ABR can provide a default route. This explains why the initial condition produces the observed failure. The direct repair is: Verify default-route reachability instead of expecting Type-5 external LSAs inside the stub area. Validate through: Check the stub router's default route and successful forwarding to an external test prefix. Other Answers A:OSPF election and adjacency expectations depend on network type; an unsuitable DR location can break multiaccess operation. A stub area's design suppresses Type-5 external advertisements while its ABR can provide a default route. C:OSPF identifies routers by 32-bit router IDs; duplicate or unexpected IDs disrupt LSDB and adjacency assumptions. A stub area's design suppresses Type-5 external advertisements while its ABR can provide a default route. D:OSPF INIT means hellos are received but two-way recognition is not yet confirmed in the neighbor lists. A stub area's design suppresses Type-5 external advertisements while its ABR can provide a default route.
Question 151 A remote OSPF stub area has no external LSAs and operators call that a failure even though an ABR supplies a default route. After applying the correction, which verification evidence most directly demonstrates that this issue is resolved? Trace the default route's OSPF source/type and validate the intended origination point. Inspect both interface timer values and confirm a stable FULL neighbor state after correction. Check the stub router's default route and successful forwarding to an external test prefix. Observe Type-7 inside the NSSA and matching Type-5 outside after correction. ExplanationCorrect Answer C:Check the stub router's default route and successful forwarding to an external test prefix. This checks the affected traffic or control-plane behavior, not merely a generic up/down indicator. The underlying mechanism is: A stub area's design suppresses Type-5 external advertisements while its ABR can provide a default route. Other Answers A:Trace the default route's OSPF source/type and validate the intended origination point. A stub area's design suppresses Type-5 external advertisements while its ABR can provide a default route. B:Inspect both interface timer values and confirm a stable FULL neighbor state after correction. A stub area's design suppresses Type-5 external advertisements while its ABR can provide a default route. D:Observe Type-7 inside the NSSA and matching Type-5 outside after correction. A stub area's design suppresses Type-5 external advertisements while its ABR can provide a default route.
Question 152 A remote OSPF stub area has no external LSAs and operators call that a failure even though an ABR supplies a default route. Which lasting design or operational safeguard best prevents this particular issue from recurring? Teach path-type hierarchy alongside cost tuning in OSPF policy review. Design durable Area 0 continuity rather than relying permanently on virtual-link workarounds. Add OSPF MTU consistency checks to routed-circuit change validation. Document expected LSA types and default behavior for each OSPF area kind. ExplanationCorrect Answer D:Document expected LSA types and default behavior for each OSPF area kind. This addresses the recurring cause: A stub area's design suppresses Type-5 external advertisements while its ABR can provide a default route. A targeted acceptance check is: Check the stub router's default route and successful forwarding to an external test prefix. Other Answers A:Teach path-type hierarchy alongside cost tuning in OSPF policy review. A stub area's design suppresses Type-5 external advertisements while its ABR can provide a default route. B:Design durable Area 0 continuity rather than relying permanently on virtual-link workarounds. A stub area's design suppresses Type-5 external advertisements while its ABR can provide a default route. C:Add OSPF MTU consistency checks to routed-circuit change validation. A stub area's design suppresses Type-5 external advertisements while its ABR can provide a default route.
Question 153 An NSSA injects a redistributed external route but routers outside the area never see it; the ABR has not translated Type-7 LSAs. Which corrective action most directly resolves the documented failure without suppressing unrelated safeguards? Check NSSA Type-7 to Type-5 translation eligibility and ABR behavior, then correct the export design. Repair Area 0 connectivity or configure a supported temporary virtual link through an eligible transit area. Set a stable unique router ID and plan an OSPF process restart where necessary for it to take effect. Make both sides' area-type settings consistent with the approved stub-area design. ExplanationCorrect Answer A:Check NSSA Type-7 to Type-5 translation eligibility and ABR behavior, then correct the export design. NSSA external LSAs are Type 7 inside the NSSA and must be translated for normal OSPF areas where appropriate. Observe Type-7 inside the NSSA and matching Type-5 outside after correction. Other Answers B:Repair Area 0 connectivity or configure a supported temporary virtual link through an eligible transit area. NSSA external LSAs are Type 7 inside the NSSA and must be translated for normal OSPF areas where appropriate. C:Set a stable unique router ID and plan an OSPF process restart where necessary for it to take effect. NSSA external LSAs are Type 7 inside the NSSA and must be translated for normal OSPF areas where appropriate. D:Make both sides' area-type settings consistent with the approved stub-area design. NSSA external LSAs are Type 7 inside the NSSA and must be translated for normal OSPF areas where appropriate.
Question 154 An NSSA injects a redistributed external route but routers outside the area never see it; the ABR has not translated Type-7 LSAs. Which technical mechanism best explains the behavior observed in this scenario? OSPF interarea routing relies on a connected backbone design; virtual links can restore logical backbone continuity in supported cases. NSSA external LSAs are Type 7 inside the NSSA and must be translated for normal OSPF areas where appropriate. OSPF SPF cost, including manually set interface cost, determines equal-cost installation within the same route type. OSPFv3 adjacencies and route exchange follow their configured interface instances and address families rather than IPv4 process network statements. ExplanationCorrect Answer B:NSSA external LSAs are Type 7 inside the NSSA and must be translated for normal OSPF areas where appropriate. This explains why the initial condition produces the observed failure. The direct repair is: Check NSSA Type-7 to Type-5 translation eligibility and ABR behavior, then correct the export design. Validate through: Observe Type-7 inside the NSSA and matching Type-5 outside after correction. Other Answers A:OSPF interarea routing relies on a connected backbone design; virtual links can restore logical backbone continuity in supported cases. NSSA external LSAs are Type 7 inside the NSSA and must be translated for normal OSPF areas where appropriate. C:OSPF SPF cost, including manually set interface cost, determines equal-cost installation within the same route type. NSSA external LSAs are Type 7 inside the NSSA and must be translated for normal OSPF areas where appropriate. D:OSPFv3 adjacencies and route exchange follow their configured interface instances and address families rather than IPv4 process network statements. NSSA external LSAs are Type 7 inside the NSSA and must be translated for normal OSPF areas where appropriate.
Question 155 An NSSA injects a redistributed external route but routers outside the area never see it; the ABR has not translated Type-7 LSAs. After applying the correction, which verification evidence most directly demonstrates that this issue is resolved? Compare route types and selected path with correct test prefixes after remediation. Verify backbone adjacency and restored interarea prefixes on the separated ABR. Observe Type-7 inside the NSSA and matching Type-5 outside after correction. Compare interface MTUs and observe EXSTART progressing through EXCHANGE to FULL after alignment. ExplanationCorrect Answer C:Observe Type-7 inside the NSSA and matching Type-5 outside after correction. This checks the affected traffic or control-plane behavior, not merely a generic up/down indicator. The underlying mechanism is: NSSA external LSAs are Type 7 inside the NSSA and must be translated for normal OSPF areas where appropriate. Other Answers A:Compare route types and selected path with correct test prefixes after remediation. NSSA external LSAs are Type 7 inside the NSSA and must be translated for normal OSPF areas where appropriate. B:Verify backbone adjacency and restored interarea prefixes on the separated ABR. NSSA external LSAs are Type 7 inside the NSSA and must be translated for normal OSPF areas where appropriate. D:Compare interface MTUs and observe EXSTART progressing through EXCHANGE to FULL after alignment. NSSA external LSAs are Type 7 inside the NSSA and must be translated for normal OSPF areas where appropriate.
Question 156 An NSSA injects a redistributed external route but routers outside the area never see it; the ABR has not translated Type-7 LSAs. Which lasting design or operational safeguard best prevents this particular issue from recurring? Specify OSPF network type and DR eligibility explicitly for hub-spoke media. Include bidirectional hello and multicast delivery tests in OSPF interface acceptance. Perform separate OSPFv3 interface and AF coverage checks in dual-stack upgrades. Define NSSA translator responsibilities and validate them in failover tests. ExplanationCorrect Answer D:Define NSSA translator responsibilities and validate them in failover tests. This addresses the recurring cause: NSSA external LSAs are Type 7 inside the NSSA and must be translated for normal OSPF areas where appropriate. A targeted acceptance check is: Observe Type-7 inside the NSSA and matching Type-5 outside after correction. Other Answers A:Specify OSPF network type and DR eligibility explicitly for hub-spoke media. NSSA external LSAs are Type 7 inside the NSSA and must be translated for normal OSPF areas where appropriate. B:Include bidirectional hello and multicast delivery tests in OSPF interface acceptance. NSSA external LSAs are Type 7 inside the NSSA and must be translated for normal OSPF areas where appropriate. C:Perform separate OSPFv3 interface and AF coverage checks in dual-stack upgrades. NSSA external LSAs are Type 7 inside the NSSA and must be translated for normal OSPF areas where appropriate.
Question 157 A broadcast Ethernet segment with three OSPF routers stays at 2-WAY between two non-DR routers; operators expect every pair to reach FULL. Which corrective action most directly resolves the documented failure without suppressing unrelated safeguards? Confirm the DR/BDR election and leave valid DROTHER-to-DROTHER 2-WAY relationships intact. Correct the explicit interface cost so eligible paths have the intended comparable OSPF cost. Repair Area 0 connectivity or configure a supported temporary virtual link through an eligible transit area. Find and correct one-way hello receipt, multicast filtering or layer-two delivery on the affected segment. ExplanationCorrect Answer A:Confirm the DR/BDR election and leave valid DROTHER-to-DROTHER 2-WAY relationships intact. On broadcast networks, DROTHER routers typically form full adjacency with DR/BDR, not each other. Show correct DR/BDR roles and FULL adjacency to them without attempting to force all pairs FULL. Other Answers B:Correct the explicit interface cost so eligible paths have the intended comparable OSPF cost. On broadcast networks, DROTHER routers typically form full adjacency with DR/BDR, not each other. C:Repair Area 0 connectivity or configure a supported temporary virtual link through an eligible transit area. On broadcast networks, DROTHER routers typically form full adjacency with DR/BDR, not each other. D:Find and correct one-way hello receipt, multicast filtering or layer-two delivery on the affected segment. On broadcast networks, DROTHER routers typically form full adjacency with DR/BDR, not each other.
Question 158 A broadcast Ethernet segment with three OSPF routers stays at 2-WAY between two non-DR routers; operators expect every pair to reach FULL. Which technical mechanism best explains the behavior observed in this scenario? OSPF neighbor creation checks hello/dead timer compatibility; mismatched intervals cause hello rejection. On broadcast networks, DROTHER routers typically form full adjacency with DR/BDR, not each other. OSPF identifies routers by 32-bit router IDs; duplicate or unexpected IDs disrupt LSDB and adjacency assumptions. A stub area's design suppresses Type-5 external advertisements while its ABR can provide a default route. ExplanationCorrect Answer B:On broadcast networks, DROTHER routers typically form full adjacency with DR/BDR, not each other. This explains why the initial condition produces the observed failure. The direct repair is: Confirm the DR/BDR election and leave valid DROTHER-to-DROTHER 2-WAY relationships intact. Validate through: Show correct DR/BDR roles and FULL adjacency to them without attempting to force all pairs FULL. Other Answers A:OSPF neighbor creation checks hello/dead timer compatibility; mismatched intervals cause hello rejection. On broadcast networks, DROTHER routers typically form full adjacency with DR/BDR, not each other. C:OSPF identifies routers by 32-bit router IDs; duplicate or unexpected IDs disrupt LSDB and adjacency assumptions. On broadcast networks, DROTHER routers typically form full adjacency with DR/BDR, not each other. D:A stub area's design suppresses Type-5 external advertisements while its ABR can provide a default route. On broadcast networks, DROTHER routers typically form full adjacency with DR/BDR, not each other.
Question 159 A broadcast Ethernet segment with three OSPF routers stays at 2-WAY between two non-DR routers; operators expect every pair to reach FULL. After applying the correction, which verification evidence most directly demonstrates that this issue is resolved? Compare interface MTUs and observe EXSTART progressing through EXCHANGE to FULL after alignment. Compare route types and selected path with correct test prefixes after remediation. Show correct DR/BDR roles and FULL adjacency to them without attempting to force all pairs FULL. Verify backbone adjacency and restored interarea prefixes on the separated ABR. ExplanationCorrect Answer C:Show correct DR/BDR roles and FULL adjacency to them without attempting to force all pairs FULL. This checks the affected traffic or control-plane behavior, not merely a generic up/down indicator. The underlying mechanism is: On broadcast networks, DROTHER routers typically form full adjacency with DR/BDR, not each other. Other Answers A:Compare interface MTUs and observe EXSTART progressing through EXCHANGE to FULL after alignment. On broadcast networks, DROTHER routers typically form full adjacency with DR/BDR, not each other. B:Compare route types and selected path with correct test prefixes after remediation. On broadcast networks, DROTHER routers typically form full adjacency with DR/BDR, not each other. D:Verify backbone adjacency and restored interarea prefixes on the separated ABR. On broadcast networks, DROTHER routers typically form full adjacency with DR/BDR, not each other.
Question 160 A broadcast Ethernet segment with three OSPF routers stays at 2-WAY between two non-DR routers; operators expect every pair to reach FULL. Which lasting design or operational safeguard best prevents this particular issue from recurring? Deploy per-link OSPF timer templates as a paired change. Assign unique stable router IDs in the deployment inventory. Design durable Area 0 continuity rather than relying permanently on virtual-link workarounds. Educate monitoring rules on expected OSPF states for each network type. ExplanationCorrect Answer D:Educate monitoring rules on expected OSPF states for each network type. This addresses the recurring cause: On broadcast networks, DROTHER routers typically form full adjacency with DR/BDR, not each other. A targeted acceptance check is: Show correct DR/BDR roles and FULL adjacency to them without attempting to force all pairs FULL. Other Answers A:Deploy per-link OSPF timer templates as a paired change. On broadcast networks, DROTHER routers typically form full adjacency with DR/BDR, not each other. B:Assign unique stable router IDs in the deployment inventory. On broadcast networks, DROTHER routers typically form full adjacency with DR/BDR, not each other. C:Design durable Area 0 continuity rather than relying permanently on virtual-link workarounds. On broadcast networks, DROTHER routers typically form full adjacency with DR/BDR, not each other.
