Question 140 An OSPF adjacency stalls in EXSTART after a path change; one device advertises a larger interface MTU in DBD packets. Which lasting design or operational safeguard best prevents this particular issue from recurring? Validate consistent stub/NSSA/normal area settings for all routers in an area. Specify OSPF network type and DR eligibility explicitly for hub-spoke media. Define NSSA translator responsibilities and validate them in failover tests. Add OSPF MTU consistency checks to routed-circuit change validation. ExplanationCorrect Answer D:Add OSPF MTU consistency checks to routed-circuit change validation. This addresses the recurring cause: OSPF database-description packet MTU checks can block database exchange when one peer cannot accept the advertised size. A targeted acceptance check is: Compare interface MTUs and observe EXSTART progressing through EXCHANGE to FULL after alignment. Other Answers A:Validate consistent stub/NSSA/normal area settings for all routers in an area. OSPF database-description packet MTU checks can block database exchange when one peer cannot accept the advertised size. B:Specify OSPF network type and DR eligibility explicitly for hub-spoke media. OSPF database-description packet MTU checks can block database exchange when one peer cannot accept the advertised size. C:Define NSSA translator responsibilities and validate them in failover tests. OSPF database-description packet MTU checks can block database exchange when one peer cannot accept the advertised size.
Question 141 Two routers on a point-to-point OSPF link log mismatched hello and dead intervals following a template migration. Which corrective action most directly resolves the documented failure without suppressing unrelated safeguards? Set compatible hello and dead timers on both ends of the same OSPF adjacency. Confirm the DR/BDR election and leave valid DROTHER-to-DROTHER 2-WAY relationships intact. Use a network type and neighbor design appropriate for the nonbroadcast multipoint topology. Verify default-route reachability instead of expecting Type-5 external LSAs inside the stub area. ExplanationCorrect Answer A:Set compatible hello and dead timers on both ends of the same OSPF adjacency. OSPF neighbor creation checks hello/dead timer compatibility; mismatched intervals cause hello rejection. Inspect both interface timer values and confirm a stable FULL neighbor state after correction. Other Answers B:Confirm the DR/BDR election and leave valid DROTHER-to-DROTHER 2-WAY relationships intact. OSPF neighbor creation checks hello/dead timer compatibility; mismatched intervals cause hello rejection. C:Use a network type and neighbor design appropriate for the nonbroadcast multipoint topology. OSPF neighbor creation checks hello/dead timer compatibility; mismatched intervals cause hello rejection. D:Verify default-route reachability instead of expecting Type-5 external LSAs inside the stub area. OSPF neighbor creation checks hello/dead timer compatibility; mismatched intervals cause hello rejection.
Question 142 Two routers on a point-to-point OSPF link log mismatched hello and dead intervals following a template migration. Which technical mechanism best explains the behavior observed in this scenario? A stub area's design suppresses Type-5 external advertisements while its ABR can provide a default route. OSPF neighbor creation checks hello/dead timer compatibility; mismatched intervals cause hello rejection. OSPF database-description packet MTU checks can block database exchange when one peer cannot accept the advertised size. On broadcast networks, DROTHER routers typically form full adjacency with DR/BDR, not each other. ExplanationCorrect Answer B:OSPF neighbor creation checks hello/dead timer compatibility; mismatched intervals cause hello rejection. This explains why the initial condition produces the observed failure. The direct repair is: Set compatible hello and dead timers on both ends of the same OSPF adjacency. Validate through: Inspect both interface timer values and confirm a stable FULL neighbor state after correction. Other Answers A:A stub area's design suppresses Type-5 external advertisements while its ABR can provide a default route. OSPF neighbor creation checks hello/dead timer compatibility; mismatched intervals cause hello rejection. C:OSPF database-description packet MTU checks can block database exchange when one peer cannot accept the advertised size. OSPF neighbor creation checks hello/dead timer compatibility; mismatched intervals cause hello rejection. D:On broadcast networks, DROTHER routers typically form full adjacency with DR/BDR, not each other. OSPF neighbor creation checks hello/dead timer compatibility; mismatched intervals cause hello rejection.
Question 143 Two routers on a point-to-point OSPF link log mismatched hello and dead intervals following a template migration. After applying the correction, which verification evidence most directly demonstrates that this issue is resolved? Check the area's LSDB and confirm expected default and no unwanted detailed interarea routes. Compare interface MTUs and observe EXSTART progressing through EXCHANGE to FULL after alignment. Inspect both interface timer values and confirm a stable FULL neighbor state after correction. Verify OSPFv3 neighbors and the expected IPv6 prefix in the routing table. ExplanationCorrect Answer C:Inspect both interface timer values and confirm a stable FULL neighbor state after correction. This checks the affected traffic or control-plane behavior, not merely a generic up/down indicator. The underlying mechanism is: OSPF neighbor creation checks hello/dead timer compatibility; mismatched intervals cause hello rejection. Other Answers A:Check the area's LSDB and confirm expected default and no unwanted detailed interarea routes. OSPF neighbor creation checks hello/dead timer compatibility; mismatched intervals cause hello rejection. B:Compare interface MTUs and observe EXSTART progressing through EXCHANGE to FULL after alignment. OSPF neighbor creation checks hello/dead timer compatibility; mismatched intervals cause hello rejection. D:Verify OSPFv3 neighbors and the expected IPv6 prefix in the routing table. OSPF neighbor creation checks hello/dead timer compatibility; mismatched intervals cause hello rejection.
Question 144 Two routers on a point-to-point OSPF link log mismatched hello and dead intervals following a template migration. Which lasting design or operational safeguard best prevents this particular issue from recurring? Perform separate OSPFv3 interface and AF coverage checks in dual-stack upgrades. Validate consistent stub/NSSA/normal area settings for all routers in an area. Educate monitoring rules on expected OSPF states for each network type. Deploy per-link OSPF timer templates as a paired change. ExplanationCorrect Answer D:Deploy per-link OSPF timer templates as a paired change. This addresses the recurring cause: OSPF neighbor creation checks hello/dead timer compatibility; mismatched intervals cause hello rejection. A targeted acceptance check is: Inspect both interface timer values and confirm a stable FULL neighbor state after correction. Other Answers A:Perform separate OSPFv3 interface and AF coverage checks in dual-stack upgrades. OSPF neighbor creation checks hello/dead timer compatibility; mismatched intervals cause hello rejection. B:Validate consistent stub/NSSA/normal area settings for all routers in an area. OSPF neighbor creation checks hello/dead timer compatibility; mismatched intervals cause hello rejection. C:Educate monitoring rules on expected OSPF states for each network type. OSPF neighbor creation checks hello/dead timer compatibility; mismatched intervals cause hello rejection.
Question 145 One side of an OSPF area is configured as stub while its neighbor treats the area as normal, so adjacency never forms. Which corrective action most directly resolves the documented failure without suppressing unrelated safeguards? Make both sides' area-type settings consistent with the approved stub-area design. Correct the interface or path MTU mismatch rather than using mtu-ignore as the default workaround. Verify OSPF route-type preference before changing interface costs. Correct the explicit interface cost so eligible paths have the intended comparable OSPF cost. ExplanationCorrect Answer A:Make both sides' area-type settings consistent with the approved stub-area design. OSPF option-bit and area-type mismatches prevent compatible neighbor formation on the same link. Verify the area flags and a FULL neighbor state after correction. Other Answers B:Correct the interface or path MTU mismatch rather than using mtu-ignore as the default workaround. OSPF option-bit and area-type mismatches prevent compatible neighbor formation on the same link. C:Verify OSPF route-type preference before changing interface costs. OSPF option-bit and area-type mismatches prevent compatible neighbor formation on the same link. D:Correct the explicit interface cost so eligible paths have the intended comparable OSPF cost. OSPF option-bit and area-type mismatches prevent compatible neighbor formation on the same link.
Question 146 One side of an OSPF area is configured as stub while its neighbor treats the area as normal, so adjacency never forms. Which technical mechanism best explains the behavior observed in this scenario? OSPF neighbor creation checks hello/dead timer compatibility; mismatched intervals cause hello rejection. OSPF option-bit and area-type mismatches prevent compatible neighbor formation on the same link. OSPF interarea routing relies on a connected backbone design; virtual links can restore logical backbone continuity in supported cases. A totally stubby area suppresses ordinary interarea summary LSAs beyond the default-route behavior. ExplanationCorrect Answer B:OSPF option-bit and area-type mismatches prevent compatible neighbor formation on the same link. This explains why the initial condition produces the observed failure. The direct repair is: Make both sides' area-type settings consistent with the approved stub-area design. Validate through: Verify the area flags and a FULL neighbor state after correction. Other Answers A:OSPF neighbor creation checks hello/dead timer compatibility; mismatched intervals cause hello rejection. OSPF option-bit and area-type mismatches prevent compatible neighbor formation on the same link. C:OSPF interarea routing relies on a connected backbone design; virtual links can restore logical backbone continuity in supported cases. OSPF option-bit and area-type mismatches prevent compatible neighbor formation on the same link. D:A totally stubby area suppresses ordinary interarea summary LSAs beyond the default-route behavior. OSPF option-bit and area-type mismatches prevent compatible neighbor formation on the same link.
Question 147 One side of an OSPF area is configured as stub while its neighbor treats the area as normal, so adjacency never forms. After applying the correction, which verification evidence most directly demonstrates that this issue is resolved? Show correct DR/BDR roles and FULL adjacency to them without attempting to force all pairs FULL. Compare interface MTUs and observe EXSTART progressing through EXCHANGE to FULL after alignment. Verify the area flags and a FULL neighbor state after correction. Confirm unique IDs and clean neighbor/LSDB convergence following an approved restart. ExplanationCorrect Answer C:Verify the area flags and a FULL neighbor state after correction. This checks the affected traffic or control-plane behavior, not merely a generic up/down indicator. The underlying mechanism is: OSPF option-bit and area-type mismatches prevent compatible neighbor formation on the same link. Other Answers A:Show correct DR/BDR roles and FULL adjacency to them without attempting to force all pairs FULL. OSPF option-bit and area-type mismatches prevent compatible neighbor formation on the same link. B:Compare interface MTUs and observe EXSTART progressing through EXCHANGE to FULL after alignment. OSPF option-bit and area-type mismatches prevent compatible neighbor formation on the same link. D:Confirm unique IDs and clean neighbor/LSDB convergence following an approved restart. OSPF option-bit and area-type mismatches prevent compatible neighbor formation on the same link.
Question 148 One side of an OSPF area is configured as stub while its neighbor treats the area as normal, so adjacency never forms. Which lasting design or operational safeguard best prevents this particular issue from recurring? Educate monitoring rules on expected OSPF states for each network type. Teach path-type hierarchy alongside cost tuning in OSPF policy review. Assign unique stable router IDs in the deployment inventory. Validate consistent stub/NSSA/normal area settings for all routers in an area. ExplanationCorrect Answer D:Validate consistent stub/NSSA/normal area settings for all routers in an area. This addresses the recurring cause: OSPF option-bit and area-type mismatches prevent compatible neighbor formation on the same link. A targeted acceptance check is: Verify the area flags and a FULL neighbor state after correction. Other Answers A:Educate monitoring rules on expected OSPF states for each network type. OSPF option-bit and area-type mismatches prevent compatible neighbor formation on the same link. B:Teach path-type hierarchy alongside cost tuning in OSPF policy review. OSPF option-bit and area-type mismatches prevent compatible neighbor formation on the same link. C:Assign unique stable router IDs in the deployment inventory. OSPF option-bit and area-type mismatches prevent compatible neighbor formation on the same link.
Question 149 A remote OSPF stub area has no external LSAs and operators call that a failure even though an ABR supplies a default route. Which corrective action most directly resolves the documented failure without suppressing unrelated safeguards? Verify default-route reachability instead of expecting Type-5 external LSAs inside the stub area. Verify OSPF route-type preference before changing interface costs. Find and correct one-way hello receipt, multicast filtering or layer-two delivery on the affected segment. Confirm the DR/BDR election and leave valid DROTHER-to-DROTHER 2-WAY relationships intact. ExplanationCorrect Answer A:Verify default-route reachability instead of expecting Type-5 external LSAs inside the stub area. A stub area's design suppresses Type-5 external advertisements while its ABR can provide a default route. Check the stub router's default route and successful forwarding to an external test prefix. Other Answers B:Verify OSPF route-type preference before changing interface costs. A stub area's design suppresses Type-5 external advertisements while its ABR can provide a default route. C:Find and correct one-way hello receipt, multicast filtering or layer-two delivery on the affected segment. A stub area's design suppresses Type-5 external advertisements while its ABR can provide a default route. D:Confirm the DR/BDR election and leave valid DROTHER-to-DROTHER 2-WAY relationships intact. A stub area's design suppresses Type-5 external advertisements while its ABR can provide a default route.
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.
