Question 290 A PE router sees a VPNv4 route in MP-BGP, but the customer VRF does not import it because the advertised route target is different. Which technical mechanism best explains the behavior observed in this scenario? VPNv4 NLRI and its route-target information require the appropriate multiprotocol BGP address family. A VPN route can exist in the MP-BGP control plane without entering a VRF that does not import its route target. A VPNv4 route can be learned but unusable if its BGP next hop cannot be resolved to a transport LSP. Route distinguishers distinguish VPNv4 prefixes, while route targets control import/export membership. ExplanationCorrect Answer B:A VPN route can exist in the MP-BGP control plane without entering a VRF that does not import its route target. This explains why the initial condition produces the observed failure. The direct repair is: Correct the intended export/import route-target association on the relevant PEs. Validate through: Inspect the VPNv4 route's extended communities and the destination VRF's import list. Other Answers A:VPNv4 NLRI and its route-target information require the appropriate multiprotocol BGP address family. A VPN route can exist in the MP-BGP control plane without entering a VRF that does not import its route target. C:A VPNv4 route can be learned but unusable if its BGP next hop cannot be resolved to a transport LSP. A VPN route can exist in the MP-BGP control plane without entering a VRF that does not import its route target. D:Route distinguishers distinguish VPNv4 prefixes, while route targets control import/export membership. A VPN route can exist in the MP-BGP control plane without entering a VRF that does not import its route target.
Question 291 A PE router sees a VPNv4 route in MP-BGP, but the customer VRF does not import it because the advertised route target is different. After applying the correction, which verification evidence most directly demonstrates that this issue is resolved? Show unique VPNv4 prefixes and verify the intended VRF import based on route target. Confirm VPNv4 routes and their extended communities appear between PE neighbors. Inspect the VPNv4 route's extended communities and the destination VRF's import list. Test allowed shared-service prefixes and a denied private subnet in both VRFs. ExplanationCorrect Answer C:Inspect the VPNv4 route's extended communities and the destination VRF's import list. This checks the affected traffic or control-plane behavior, not merely a generic up/down indicator. The underlying mechanism is: A VPN route can exist in the MP-BGP control plane without entering a VRF that does not import its route target. Other Answers A:Show unique VPNv4 prefixes and verify the intended VRF import based on route target. A VPN route can exist in the MP-BGP control plane without entering a VRF that does not import its route target. B:Confirm VPNv4 routes and their extended communities appear between PE neighbors. A VPN route can exist in the MP-BGP control plane without entering a VRF that does not import its route target. D:Test allowed shared-service prefixes and a denied private subnet in both VRFs. A VPN route can exist in the MP-BGP control plane without entering a VRF that does not import its route target.
Question 292 A PE router sees a VPNv4 route in MP-BGP, but the customer VRF does not import it because the advertised route target is different. Which lasting design or operational safeguard best prevents this particular issue from recurring? Require explicit encryption classification for every MPLS VPN service carrying sensitive information. Document route distinguisher and route-target roles separately in service templates. Include VPN address-family and community carriage in PE-to-PE peering checklists. Validate matching route-target design at both ends of every L3 VPN service. ExplanationCorrect Answer D:Validate matching route-target design at both ends of every L3 VPN service. This addresses the recurring cause: A VPN route can exist in the MP-BGP control plane without entering a VRF that does not import its route target. A targeted acceptance check is: Inspect the VPNv4 route's extended communities and the destination VRF's import list. Other Answers A:Require explicit encryption classification for every MPLS VPN service carrying sensitive information. A VPN route can exist in the MP-BGP control plane without entering a VRF that does not import its route target. B:Document route distinguisher and route-target roles separately in service templates. A VPN route can exist in the MP-BGP control plane without entering a VRF that does not import its route target. C:Include VPN address-family and community carriage in PE-to-PE peering checklists. A VPN route can exist in the MP-BGP control plane without entering a VRF that does not import its route target.
Question 293 A carrier engineer believes matching route distinguishers alone should make VPNv4 routes exchange between two sites, but no remote VRF route appears. Which corrective action most directly resolves the documented failure without suppressing unrelated safeguards? Configure appropriate route-target policies; keep route distinguishers for VPN route uniqueness. Trace the VPN route's next hop and service-label/transport-label resolution across the provider core. Replace broad route-target imports with the designed selective route sharing mechanism and filters. Explain the separation benefit of L3 VPN and specify independent encryption where confidentiality is required. ExplanationCorrect Answer A:Configure appropriate route-target policies; keep route distinguishers for VPN route uniqueness. Route distinguishers distinguish VPNv4 prefixes, while route targets control import/export membership. Show unique VPNv4 prefixes and verify the intended VRF import based on route target. Other Answers B:Trace the VPN route's next hop and service-label/transport-label resolution across the provider core. Route distinguishers distinguish VPNv4 prefixes, while route targets control import/export membership. C:Replace broad route-target imports with the designed selective route sharing mechanism and filters. Route distinguishers distinguish VPNv4 prefixes, while route targets control import/export membership. D:Explain the separation benefit of L3 VPN and specify independent encryption where confidentiality is required. Route distinguishers distinguish VPNv4 prefixes, while route targets control import/export membership.
Question 294 A carrier engineer believes matching route distinguishers alone should make VPNv4 routes exchange between two sites, but no remote VRF route appears. Which technical mechanism best explains the behavior observed in this scenario? A VPNv4 route can be learned but unusable if its BGP next hop cannot be resolved to a transport LSP. Route distinguishers distinguish VPNv4 prefixes, while route targets control import/export membership. A VPN route can exist in the MP-BGP control plane without entering a VRF that does not import its route target. MPLS VPN labels support traffic separation and forwarding context, not cryptographic confidentiality of the payload. ExplanationCorrect Answer B:Route distinguishers distinguish VPNv4 prefixes, while route targets control import/export membership. This explains why the initial condition produces the observed failure. The direct repair is: Configure appropriate route-target policies; keep route distinguishers for VPN route uniqueness. Validate through: Show unique VPNv4 prefixes and verify the intended VRF import based on route target. Other Answers A:A VPNv4 route can be learned but unusable if its BGP next hop cannot be resolved to a transport LSP. Route distinguishers distinguish VPNv4 prefixes, while route targets control import/export membership. C:A VPN route can exist in the MP-BGP control plane without entering a VRF that does not import its route target. Route distinguishers distinguish VPNv4 prefixes, while route targets control import/export membership. D:MPLS VPN labels support traffic separation and forwarding context, not cryptographic confidentiality of the payload. Route distinguishers distinguish VPNv4 prefixes, while route targets control import/export membership.
Question 295 A carrier engineer believes matching route distinguishers alone should make VPNv4 routes exchange between two sites, but no remote VRF route appears. After applying the correction, which verification evidence most directly demonstrates that this issue is resolved? Inspect the customer VRF route tables and prove only authorized route targets are imported. Confirm VPNv4 routes and their extended communities appear between PE neighbors. Show unique VPNv4 prefixes and verify the intended VRF import based on route target. Test allowed shared-service prefixes and a denied private subnet in both VRFs. ExplanationCorrect Answer C:Show unique VPNv4 prefixes and verify the intended VRF import based on route target. This checks the affected traffic or control-plane behavior, not merely a generic up/down indicator. The underlying mechanism is: Route distinguishers distinguish VPNv4 prefixes, while route targets control import/export membership. Other Answers A:Inspect the customer VRF route tables and prove only authorized route targets are imported. Route distinguishers distinguish VPNv4 prefixes, while route targets control import/export membership. B:Confirm VPNv4 routes and their extended communities appear between PE neighbors. Route distinguishers distinguish VPNv4 prefixes, while route targets control import/export membership. D:Test allowed shared-service prefixes and a denied private subnet in both VRFs. Route distinguishers distinguish VPNv4 prefixes, while route targets control import/export membership.
Question 296 A carrier engineer believes matching route distinguishers alone should make VPNv4 routes exchange between two sites, but no remote VRF route appears. Which lasting design or operational safeguard best prevents this particular issue from recurring? Run layered CE-to-CE checks covering VRF routes, VPN labels and MPLS core connectivity. Verify PE loopback reachability and transport labels as part of new VPN service turn-up. Apply least-privilege route-leak policies and negative test cases across tenant contexts. Document route distinguisher and route-target roles separately in service templates. ExplanationCorrect Answer D:Document route distinguisher and route-target roles separately in service templates. This addresses the recurring cause: Route distinguishers distinguish VPNv4 prefixes, while route targets control import/export membership. A targeted acceptance check is: Show unique VPNv4 prefixes and verify the intended VRF import based on route target. Other Answers A:Run layered CE-to-CE checks covering VRF routes, VPN labels and MPLS core connectivity. Route distinguishers distinguish VPNv4 prefixes, while route targets control import/export membership. B:Verify PE loopback reachability and transport labels as part of new VPN service turn-up. Route distinguishers distinguish VPNv4 prefixes, while route targets control import/export membership. C:Apply least-privilege route-leak policies and negative test cases across tenant contexts. Route distinguishers distinguish VPNv4 prefixes, while route targets control import/export membership.
Question 297 A branch CE can reach its directly connected PE but not the remote CE although both PE VRFs have the customer prefix. Which corrective action most directly resolves the documented failure without suppressing unrelated safeguards? Trace the VPN route's next hop and service-label/transport-label resolution across the provider core. Activate the VPNv4 address family and required route-target extended-community exchange. Check VRF import/export route-target policy and remove the unintended cross-tenant import. Replace broad route-target imports with the designed selective route sharing mechanism and filters. ExplanationCorrect Answer A:Trace the VPN route's next hop and service-label/transport-label resolution across the provider core. MPLS L3 VPN delivery relies on both customer route distribution and a functioning PE-to-PE labeled transport path. Verify VRF RIB, MP-BGP route next hop and label stack all the way to remote PE. Other Answers B:Activate the VPNv4 address family and required route-target extended-community exchange. MPLS L3 VPN delivery relies on both customer route distribution and a functioning PE-to-PE labeled transport path. C:Check VRF import/export route-target policy and remove the unintended cross-tenant import. MPLS L3 VPN delivery relies on both customer route distribution and a functioning PE-to-PE labeled transport path. D:Replace broad route-target imports with the designed selective route sharing mechanism and filters. MPLS L3 VPN delivery relies on both customer route distribution and a functioning PE-to-PE labeled transport path.
Question 298 A branch CE can reach its directly connected PE but not the remote CE although both PE VRFs have the customer prefix. Which technical mechanism best explains the behavior observed in this scenario? MPLS VPN labels support traffic separation and forwarding context, not cryptographic confidentiality of the payload. MPLS L3 VPN delivery relies on both customer route distribution and a functioning PE-to-PE labeled transport path. A VPNv4 route can be learned but unusable if its BGP next hop cannot be resolved to a transport LSP. Route-target membership can import entire sets of VPN routes unless the design constrains shared-service reachability. ExplanationCorrect Answer B:MPLS L3 VPN delivery relies on both customer route distribution and a functioning PE-to-PE labeled transport path. This explains why the initial condition produces the observed failure. The direct repair is: Trace the VPN route's next hop and service-label/transport-label resolution across the provider core. Validate through: Verify VRF RIB, MP-BGP route next hop and label stack all the way to remote PE. Other Answers A:MPLS VPN labels support traffic separation and forwarding context, not cryptographic confidentiality of the payload. MPLS L3 VPN delivery relies on both customer route distribution and a functioning PE-to-PE labeled transport path. C:A VPNv4 route can be learned but unusable if its BGP next hop cannot be resolved to a transport LSP. MPLS L3 VPN delivery relies on both customer route distribution and a functioning PE-to-PE labeled transport path. D:Route-target membership can import entire sets of VPN routes unless the design constrains shared-service reachability. MPLS L3 VPN delivery relies on both customer route distribution and a functioning PE-to-PE labeled transport path.
Question 299 A branch CE can reach its directly connected PE but not the remote CE although both PE VRFs have the customer prefix. After applying the correction, which verification evidence most directly demonstrates that this issue is resolved? Inspect the customer VRF route tables and prove only authorized route targets are imported. Validate separate encryption controls, such as an approved IPsec overlay, rather than treating label traces as security proof. Verify VRF RIB, MP-BGP route next hop and label stack all the way to remote PE. Inspect the VPNv4 route's extended communities and the destination VRF's import list. ExplanationCorrect Answer C:Verify VRF RIB, MP-BGP route next hop and label stack all the way to remote PE. This checks the affected traffic or control-plane behavior, not merely a generic up/down indicator. The underlying mechanism is: MPLS L3 VPN delivery relies on both customer route distribution and a functioning PE-to-PE labeled transport path. Other Answers A:Inspect the customer VRF route tables and prove only authorized route targets are imported. MPLS L3 VPN delivery relies on both customer route distribution and a functioning PE-to-PE labeled transport path. B:Validate separate encryption controls, such as an approved IPsec overlay, rather than treating label traces as security proof. MPLS L3 VPN delivery relies on both customer route distribution and a functioning PE-to-PE labeled transport path. D:Inspect the VPNv4 route's extended communities and the destination VRF's import list. MPLS L3 VPN delivery relies on both customer route distribution and a functioning PE-to-PE labeled transport path.
Question 300 A branch CE can reach its directly connected PE but not the remote CE although both PE VRFs have the customer prefix. Which lasting design or operational safeguard best prevents this particular issue from recurring? Validate matching route-target design at both ends of every L3 VPN service. Require explicit encryption classification for every MPLS VPN service carrying sensitive information. Verify PE loopback reachability and transport labels as part of new VPN service turn-up. Run layered CE-to-CE checks covering VRF routes, VPN labels and MPLS core connectivity. ExplanationCorrect Answer D:Run layered CE-to-CE checks covering VRF routes, VPN labels and MPLS core connectivity. This addresses the recurring cause: MPLS L3 VPN delivery relies on both customer route distribution and a functioning PE-to-PE labeled transport path. A targeted acceptance check is: Verify VRF RIB, MP-BGP route next hop and label stack all the way to remote PE. Other Answers A:Validate matching route-target design at both ends of every L3 VPN service. MPLS L3 VPN delivery relies on both customer route distribution and a functioning PE-to-PE labeled transport path. B:Require explicit encryption classification for every MPLS VPN service carrying sensitive information. MPLS L3 VPN delivery relies on both customer route distribution and a functioning PE-to-PE labeled transport path. C:Verify PE loopback reachability and transport labels as part of new VPN service turn-up. MPLS L3 VPN delivery relies on both customer route distribution and a functioning PE-to-PE labeled transport path.
