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Question 1050
A remote office assigns clients addresses from 169.254.0.0/16 and expects them to be reachable through a routed WAN. Choose THREE statements that form the design action, direct verification, and deployment safeguard. (Choose THREE.)
- Neighbor discovery and SLAAC operate independently on both VLANs with no on-link ambiguity.
- Assign distinct /64 prefixes per routed IPv6 segment from a hierarchical site allocation.
- Reserve a contiguous per-site allocation and validate all router advertisements during cutover.
- Use a legitimately allocated private or global prefix at the remote site and reserve IPv4 link-local for local-only communication.
- Audit DHCP and static address assignments prior to moving the site to its routed block.
- Clients reach the headquarters destination over the routed path using the approved office prefix.
Explanation
Correct Answers
D:Use a legitimately allocated private or global prefix at the remote site and reserve IPv4 link-local for local-only communication. This is the corrective design for the stated topology.
E:Audit DHCP and static address assignments prior to moving the site to its routed block. This applies directly to the reported network-design requirement.
F:Clients reach the headquarters destination over the routed path using the approved office prefix. This is the observable acceptance check for the change.
Incorrect Answers
A:This offered choice, “Neighbor discovery and SLAAC operate independently on both VLANs with no on-link ambiguity”, addresses a separate concern. This statement relates to a different requirement: A campus plans IPv6 addressing with one /64 shared between two routed VLAN interfaces in different buildings. It does not address the condition described here.
B:This offered choice, “Assign distinct /64 prefixes per routed IPv6 segment from a hierarchical site allocation”, addresses a separate concern. This statement relates to a different requirement: A campus plans IPv6 addressing with one /64 shared between two routed VLAN interfaces in different buildings. It does not address the condition described here.
C:This offered choice, “Reserve a contiguous per-site allocation and validate all router advertisements during cutover”, addresses a separate concern. This statement relates to a different requirement: A campus plans IPv6 addressing with one /64 shared between two routed VLAN interfaces in different buildings. It does not address the condition described here.
Question 1051
A branch aggregation point has both IS-IS and OSPF neighbors with multiple equal-cost exits; traffic unexpectedly hairpins through a data center. Select TWO statements that together define the best corrective design and its acceptance evidence. (Choose TWO.)
- Apply selective redistribution, tagging and route filtering at clearly defined protocol boundaries.
- Simplify path preference at domain boundaries and choose intended transit points based on actual traffic flows.
- Build point-to-point routed access uplinks and use ECMP-capable IGP convergence at the access layer.
- A representative prefix crosses the boundary once and retains deterministic return routing.
- Intercampus traffic follows authorized shortest feasible paths rather than unwanted data-center detours.
Explanation
Correct Answers
B:Simplify path preference at domain boundaries and choose intended transit points based on actual traffic flows. This applies directly to the reported network-design requirement.
E:Intercampus traffic follows authorized shortest feasible paths rather than unwanted data-center detours. This is the observable acceptance check for the change.
Incorrect Answers
A:This offered choice, “Apply selective redistribution, tagging and route filtering at clearly defined protocol boundaries”, addresses a separate concern. That answer belongs to this other scenario: Two intercampus routers redistribute OSPF and EIGRP in both directions, making route origin hard to track. It does not establish the necessary change in this case.
C:This offered choice, “Build point-to-point routed access uplinks and use ECMP-capable IGP convergence at the access layer”, addresses a separate concern. That answer belongs to this other scenario: A routed-access campus needs equal-cost forwarding to two distribution routers while keeping each VLAN local to one wiring closet. It does not establish the necessary change in this case.
D:This offered choice, “A representative prefix crosses the boundary once and retains deterministic return routing”, addresses a separate concern. That answer belongs to this other scenario: Two intercampus routers redistribute OSPF and EIGRP in both directions, making route origin hard to track. It does not establish the necessary change in this case.
Question 1052
Two hospitals need their existing Ethernet VLANs extended across a provider circuit but their engineers incorrectly request a routed L3VPN. Choose THREE statements that form the design action, direct verification, and deployment safeguard. (Choose THREE.)
- Expected tagged traffic traverses the authorized EVC and unrelated tags are isolated.
- Verify UNI/ENNI behavior and available MTU across the provider boundary.
- The approved VLAN service operates end to end without leaking unrelated hospital segments.
- Align the service's supported VLAN encapsulation and mapping with the carrier's EVC definition.
- Evaluate a provider Layer 2 VPN or Ethernet virtual circuit with explicit loop, MTU and broadcast containment design.
- Validate the true need for L2 extension and the risk of spanning a failure domain between facilities.
Explanation
Correct Answers
C:The approved VLAN service operates end to end without leaking unrelated hospital segments. This is the observable acceptance check for the change.
E:Evaluate a provider Layer 2 VPN or Ethernet virtual circuit with explicit loop, MTU and broadcast containment design. This is the corrective design for the stated topology.
F:Validate the true need for L2 extension and the risk of spanning a failure domain between facilities. This applies directly to the reported network-design requirement.
Incorrect Answers
A:This offered choice, “Expected tagged traffic traverses the authorized EVC and unrelated tags are isolated”, addresses a separate concern. This statement relates to a different requirement: Two enterprise buildings use separate Metro Ethernet UNI ports, yet their operators assume the provider will preserve any configured customer VLAN ID. It does not address the condition described here.
B:This offered choice, “Verify UNI/ENNI behavior and available MTU across the provider boundary”, addresses a separate concern. This statement relates to a different requirement: Two enterprise buildings use separate Metro Ethernet UNI ports, yet their operators assume the provider will preserve any configured customer VLAN ID. It does not address the condition described here.
D:This offered choice, “Align the service's supported VLAN encapsulation and mapping with the carrier's EVC definition”, addresses a separate concern. This statement relates to a different requirement: Two enterprise buildings use separate Metro Ethernet UNI ports, yet their operators assume the provider will preserve any configured customer VLAN ID. It does not address the condition described here.
Question 1053
A support dashboard needs regular CPU and interface-rate samples even when values remain unchanged. Select TWO statements that together define the best corrective design and its acceptance evidence. (Choose TWO.)
- The receiver continues receiving timestamped samples during steady-state operation.
- Use a periodic telemetry subscription at a measured cadence suitable for trending and capacity planning.
- Design timestamped telemetry with source identification and collector reconnection/backfill policy as supported.
- A controlled interface-down event arrives with correct device identity and event ordering after reconnection.
- Distinguish IETF standards-track models from OpenConfig community models and vendor-native schema ownership.
Explanation
Correct Answers
A:The receiver continues receiving timestamped samples during steady-state operation. This is the observable acceptance check for the change.
B:Use a periodic telemetry subscription at a measured cadence suitable for trending and capacity planning. This applies directly to the reported network-design requirement.
Incorrect Answers
C:This offered choice, “Design timestamped telemetry with source identification and collector reconnection/backfill policy as supported”, addresses a separate concern. That answer belongs to this other scenario: A security operations service needs authoritative interface state changes, not a dashboard that replays stale telemetry after collector failure. It does not establish the necessary change in this case.
D:This offered choice, “A controlled interface-down event arrives with correct device identity and event ordering after reconnection”, addresses a separate concern. That answer belongs to this other scenario: A security operations service needs authoritative interface state changes, not a dashboard that replays stale telemetry after collector failure. It does not establish the necessary change in this case.
E:This offered choice, “Distinguish IETF standards-track models from OpenConfig community models and vendor-native schema ownership”, addresses a separate concern. That answer belongs to this other scenario: A standards group needs an interoperable interface model but mistakenly calls every IETF YANG module an OpenConfig model. It does not establish the necessary change in this case.
Question 1054
A 20-Mbps backup link replaces a 200-Mbps primary WAN but the shaper keeps its 200-Mbps limit after failover. Choose THREE statements that form the design action, direct verification, and deployment safeguard. (Choose THREE.)
- Create feasible bandwidth allocations and an explicit priority bandwidth budget that sums within supported scheduler constraints.
- Include control, default, and scavenger classes when totaling reserved bandwidth.
- Verify backup throughput and overhead during real failover testing.
- All essential classes receive their planned treatment without violating actual egress capacity.
- Backup traffic stays within the 20-Mbps service rate and critical classes remain usable.
- Use link-aware QoS policy to update shaping and class allocations for the reduced-capacity backup transport.
Explanation
Correct Answers
C:Verify backup throughput and overhead during real failover testing. This applies directly to the reported network-design requirement.
E:Backup traffic stays within the 20-Mbps service rate and critical classes remain usable. This is the observable acceptance check for the change.
F:Use link-aware QoS policy to update shaping and class allocations for the reduced-capacity backup transport. This is the corrective design for the stated topology.
Incorrect Answers
A:This offered choice, “Create feasible bandwidth allocations and an explicit priority bandwidth budget that sums within supported scheduler constraints”, addresses a separate concern. This statement relates to a different requirement: A switch QoS scheduler guarantees 30% to backup traffic and 80% to voice under full congestion, exceeding possible link capacity. It does not address the condition described here.
B:This offered choice, “Include control, default, and scavenger classes when totaling reserved bandwidth”, addresses a separate concern. This statement relates to a different requirement: A switch QoS scheduler guarantees 30% to backup traffic and 80% to voice under full congestion, exceeding possible link capacity. It does not address the condition described here.
D:This offered choice, “All essential classes receive their planned treatment without violating actual egress capacity”, addresses a separate concern. This statement relates to a different requirement: A switch QoS scheduler guarantees 30% to backup traffic and 80% to voice under full congestion, exceeding possible link capacity. It does not address the condition described here.
Question 1055
Multiple campus cores are connected in a full mesh, creating expensive adjacency and troubleshooting overhead. Select TWO statements that together define the best corrective design and its acceptance evidence. (Choose TWO.)
- Design VRF-aware border handoffs or supported segmentation-preserving transit consistent with the policy boundary.
- External routes and flows remain segmented by approved virtual network.
- Size the entire routed underlay MTU for supported encapsulated payloads rather than only endpoint Ethernet frames.
- A single link failure preserves required site connectivity without unnecessary adjacency proliferation.
- Use a topology appropriate to business resilience requirements, such as a structured regional core with redundant distribution paths.
Explanation
Correct Answers
D:A single link failure preserves required site connectivity without unnecessary adjacency proliferation. This is the observable acceptance check for the change.
E:Use a topology appropriate to business resilience requirements, such as a structured regional core with redundant distribution paths. This applies directly to the reported network-design requirement.
Incorrect Answers
A:This offered choice, “Design VRF-aware border handoffs or supported segmentation-preserving transit consistent with the policy boundary”, addresses a separate concern. That answer belongs to this other scenario: A campus has a fabric border but its external firewall cannot distinguish multiple endpoint VNs leaving the fabric. It does not establish the necessary change in this case.
B:This offered choice, “External routes and flows remain segmented by approved virtual network”, addresses a separate concern. That answer belongs to this other scenario: A campus has a fabric border but its external firewall cannot distinguish multiple endpoint VNs leaving the fabric. It does not establish the necessary change in this case.
C:This offered choice, “Size the entire routed underlay MTU for supported encapsulated payloads rather than only endpoint Ethernet frames”, addresses a separate concern. That answer belongs to this other scenario: Fabric edge nodes encapsulate packets, but the underlay path MTU is too small for added VXLAN overhead. It does not establish the necessary change in this case.
Question 1056
A branch OSPF design selects a totally stubby area but an application requires type-3 interarea routes rather than only the default. Choose THREE statements that form the design action, direct verification, and deployment safeguard. (Choose THREE.)
- Prefer durable backbone topology repair over making virtual links a permanent substitute for good design.
- The branch receives the intended interarea destinations and no unwanted external LSAs.
- Audit reachable service prefixes and router roles before enabling area restrictions.
- Use explicit route tags, prefix filtering, and redistribution boundaries to block feedback loops.
- Required external routes originate inside the NSSA and are translated into the rest of the OSPF domain as designed.
- Choose the appropriate stub-area variant or redesign to preserve required interarea summaries.
Explanation
Correct Answers
B:The branch receives the intended interarea destinations and no unwanted external LSAs. This is the observable acceptance check for the change.
C:Audit reachable service prefixes and router roles before enabling area restrictions. This applies directly to the reported network-design requirement.
F:Choose the appropriate stub-area variant or redesign to preserve required interarea summaries. This is the corrective design for the stated topology.
Incorrect Answers
A:This offered choice, “Prefer durable backbone topology repair over making virtual links a permanent substitute for good design”, addresses a separate concern. This statement relates to a different requirement: A campus OSPF area 0 is split into disconnected islands connected only by another area; route distribution is unstable. It does not address the condition described here.
D:This offered choice, “Use explicit route tags, prefix filtering, and redistribution boundaries to block feedback loops”, addresses a separate concern. This statement relates to a different requirement: Branch A and B redistribute external BGP into OSPF, then advertise resulting routes back into BGP at the opposite edge. It does not address the condition described here.
E:This offered choice, “Required external routes originate inside the NSSA and are translated into the rest of the OSPF domain as designed”, addresses a separate concern. This statement relates to a different requirement: A remote branch uses an OSPF stub area but a design change introduces an ASBR that must redistribute external routes within it. It does not address the condition described here.
Question 1057
A city campus needs a 10-Gbps local metro interconnect with SLA and carrier demarcation, but the proposed design assumes standard broadband internet guarantees. Select TWO statements that together define the best corrective design and its acceptance evidence. (Choose TWO.)
- Measured throughput and failover meet the contractual envelope across the metro sites.
- Evaluate policy-controlled local internet breakout with appropriate security inspection and application path measurement.
- Select an appropriate private APN, outbound-initiated overlay, or routable-address service depending on carrier capabilities.
- The branch establishes the required controlled overlay sessions without depending on unsupported unsolicited inbound access.
- Evaluate a Metro Ethernet service with committed bandwidth, fault demarcation and suitable Ethernet handoff.
Explanation
Correct Answers
A:Measured throughput and failover meet the contractual envelope across the metro sites. This is the observable acceptance check for the change.
E:Evaluate a Metro Ethernet service with committed bandwidth, fault demarcation and suitable Ethernet handoff. This applies directly to the reported network-design requirement.
Incorrect Answers
B:This offered choice, “Evaluate policy-controlled local internet breakout with appropriate security inspection and application path measurement”, addresses a separate concern. That answer belongs to this other scenario: A retail design directs all cloud SaaS traffic through headquarters even though local internet breakout is allowed and latency is poor. It does not establish the necessary change in this case.
C:This offered choice, “Select an appropriate private APN, outbound-initiated overlay, or routable-address service depending on carrier capabilities”, addresses a separate concern. That answer belongs to this other scenario: An industrial site uses 4G LTE as primary WAN, and its routing team assumes public inbound addresses remain reachable through carrier-grade NAT. It does not establish the necessary change in this case.
D:This offered choice, “The branch establishes the required controlled overlay sessions without depending on unsupported unsolicited inbound access”, addresses a separate concern. That answer belongs to this other scenario: An industrial site uses 4G LTE as primary WAN, and its routing team assumes public inbound addresses remain reachable through carrier-grade NAT. It does not establish the necessary change in this case.
Question 1058
A branch QoS policy matches all TCP 443 traffic as video, including large software downloads. Choose THREE statements that form the design action, direct verification, and deployment safeguard. (Choose THREE.)
- Verify classification with application telemetry and manage encrypted-traffic visibility constraints.
- Use validated application classification or more precise traffic identity instead of assuming TCP port 443 defines one service.
- Only the intended interactive application receives real-time class treatment during a test.
- Prevent uncontrolled high-rate management flows from abusing the protected class.
- Control-plane adjacencies and monitoring remain stable during representative congestion.
- Protect essential routing/control traffic within bounded QoS classes at actual bottlenecks.
Explanation
Correct Answers
A:Verify classification with application telemetry and manage encrypted-traffic visibility constraints. This applies directly to the reported network-design requirement.
B:Use validated application classification or more precise traffic identity instead of assuming TCP port 443 defines one service. This is the corrective design for the stated topology.
C:Only the intended interactive application receives real-time class treatment during a test. This is the observable acceptance check for the change.
Incorrect Answers
D:This offered choice, “Prevent uncontrolled high-rate management flows from abusing the protected class”, addresses a separate concern. This statement relates to a different requirement: A campus QoS policy gives low priority to routing keepalives and network monitoring, and routing adjacencies flap during congestion. It does not address the condition described here.
E:This offered choice, “Control-plane adjacencies and monitoring remain stable during representative congestion”, addresses a separate concern. This statement relates to a different requirement: A campus QoS policy gives low priority to routing keepalives and network monitoring, and routing adjacencies flap during congestion. It does not address the condition described here.
F:This offered choice, “Protect essential routing/control traffic within bounded QoS classes at actual bottlenecks”, addresses a separate concern. This statement relates to a different requirement: A campus QoS policy gives low priority to routing keepalives and network monitoring, and routing adjacencies flap during congestion. It does not address the condition described here.
Question 1059
Two campus distribution routers each have a single power feed from the same rack PDU, yet the architecture counts them as separate fault domains. Select TWO statements that together define the best corrective design and its acceptance evidence. (Choose TWO.)
- Both routed uplinks forward to the rest of campus and a link failure reroutes traffic without a campus STP event.
- Build point-to-point routed access uplinks and use ECMP-capable IGP convergence at the access layer.
- Loss of either PDU leaves the campus default gateway and upstream traffic operating.
- Provide independent power infrastructure for each redundant network node and validate dual-path resilience.
- Keep local VLAN boundaries and provide a scoped supported discovery relay or service registration alternative.
Explanation
Correct Answers
C:Loss of either PDU leaves the campus default gateway and upstream traffic operating. This is the observable acceptance check for the change.
D:Provide independent power infrastructure for each redundant network node and validate dual-path resilience. This applies directly to the reported network-design requirement.
Incorrect Answers
A:This offered choice, “Both routed uplinks forward to the rest of campus and a link failure reroutes traffic without a campus STP event”, addresses a separate concern. That answer belongs to this other scenario: A routed-access campus needs equal-cost forwarding to two distribution routers while keeping each VLAN local to one wiring closet. It does not establish the necessary change in this case.
B:This offered choice, “Build point-to-point routed access uplinks and use ECMP-capable IGP convergence at the access layer”, addresses a separate concern. That answer belongs to this other scenario: A routed-access campus needs equal-cost forwarding to two distribution routers while keeping each VLAN local to one wiring closet. It does not establish the necessary change in this case.
E:That answer belongs to this other scenario: A campus access layer spans large broadcast domains for print discovery despite an architecture target of small local VLANs. It does not establish the necessary change in this case.
Question 1060
A branch EIGRP router advertises remote routes back into its hub and occasionally becomes a transit path between hubs. Choose THREE statements that form the design action, direct verification, and deployment safeguard. (Choose THREE.)
- Validate advertised stub route classes and redundancy if the branch has multiple uplinks.
- Review route reachability and summary boundaries before introducing stub behavior.
- Failed-route convergence completes without broad stuck-in-active propagation.
- Evaluate whether additional-paths or path diversity is required and supported by the topology and platforms.
- Hubs avoid querying through the branch as a transit path and branch-local prefixes remain visible.
- Configure an appropriate EIGRP stub design on the branch while allowing its locally connected routes to reach the hubs.
Explanation
Correct Answers
A:Validate advertised stub route classes and redundancy if the branch has multiple uplinks. This applies directly to the reported network-design requirement.
E:Hubs avoid querying through the branch as a transit path and branch-local prefixes remain visible. This is the observable acceptance check for the change.
F:Configure an appropriate EIGRP stub design on the branch while allowing its locally connected routes to reach the hubs. This is the corrective design for the stated topology.
Incorrect Answers
B:This offered choice, “Review route reachability and summary boundaries before introducing stub behavior”, addresses a separate concern. This statement relates to a different requirement: An EIGRP core has routes stuck active after one WAN path fails and queries spread into many remote sites. It does not address the condition described here.
C:This offered choice, “Failed-route convergence completes without broad stuck-in-active propagation”, addresses a separate concern. This statement relates to a different requirement: An EIGRP core has routes stuck active after one WAN path fails and queries spread into many remote sites. It does not address the condition described here.
D:This statement relates to a different requirement: An iBGP route reflector sees several candidate routes to the same destination but advertises only its best path to clients. It does not address the condition described here.
Designing Cisco Enterprise Networks (ENSLD) (300-420) Practice Tests
