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Question 390
A remote office assigns clients addresses from 169.254.0.0/16 and expects them to be reachable through a routed WAN. Which observed result would most directly prove the design meets the intended goal?
- Clients reach the headquarters destination over the routed path using the approved office prefix.
- Neighbor discovery and SLAAC operate independently on both VLANs with no on-link ambiguity.
- Local access failures generate bounded LSDB changes without disrupting unrelated branches.
- The intended adjacency comes up at the correct level and interarea destinations remain reachable.
Explanation
Correct Answer
A:Use a legitimately allocated private or global prefix at the remote site and reserve IPv4 link-local for local-only communication. Verify the resulting network behavior rather than relying only on the saved configuration.
Incorrect Answers
B:This observation relates to a different topology: A campus plans IPv6 addressing with one /64 shared between two routed VLAN interfaces in different buildings. It does not verify the present outcome.
C:This observation relates to a different topology: An OSPF deployment puts all 600 remote access switches into area 0 and floods changes to every site. It does not verify the present outcome.
D:This observation relates to a different topology: New routers have valid IP addresses but IS-IS peers in separate areas never form a level-1 adjacency. It does not verify the present outcome.
Question 391
A branch aggregation point has both IS-IS and OSPF neighbors with multiple equal-cost exits; traffic unexpectedly hairpins through a data center. Which observed result would most directly prove the design meets the intended goal?
- 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.
- Representative flows distribute across eligible next hops while a single ordered flow remains stable.
- Both routed uplinks forward to the rest of campus and a link failure reroutes traffic without a campus STP event.
Explanation
Correct Answer
B:Simplify path preference at domain boundaries and choose intended transit points based on actual traffic flows. Verify the resulting network behavior rather than relying only on the saved configuration.
Incorrect Answers
A:This observation relates to a different topology: Two intercampus routers redistribute OSPF and EIGRP in both directions, making route origin hard to track. It does not verify the present outcome.
C:This observation relates to a different topology: A multicampus network has two equal-cost paths but the design assumes packets always alternate evenly across every individual packet. It does not verify the present outcome.
D:This observation relates to a different topology: A routed-access campus needs equal-cost forwarding to two distribution routers while keeping each VLAN local to one wiring closet. It does not verify the present outcome.
Question 392
Two hospitals need their existing Ethernet VLANs extended across a provider circuit but their engineers incorrectly request a routed L3VPN. Which observed result would most directly prove the design meets the intended goal?
- Expected tagged traffic traverses the authorized EVC and unrelated tags are isolated.
- Each branch exchanges only authorized VPN routes while the provider backbone transports traffic without L2 extension.
- The approved VLAN service operates end to end without leaking unrelated hospital segments.
- Enterprise routers form intended routing neighbors over the circuit while provider internals remain hidden.
Explanation
Correct Answer
C:Evaluate a provider Layer 2 VPN or Ethernet virtual circuit with explicit loop, MTU and broadcast containment design. Verify the resulting network behavior rather than relying only on the saved configuration.
Incorrect Answers
A:This observation relates to a different topology: 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 verify the present outcome.
B:This observation relates to a different topology: A customer needs private route separation for 12 branches over a shared provider backbone, not a single Ethernet broadcast domain. It does not verify the present outcome.
D:That option relates to this separate design case: A financial organization leases a transparent point-to-point Ethernet service but requires independent routing at each site. It does not answer the current requirement.
Question 393
A support dashboard needs regular CPU and interface-rate samples even when values remain unchanged. Which observed result would most directly prove the design meets the intended goal?
- A controlled status change reaches the collector promptly without waiting for the next periodic poll.
- A controlled interface-down event arrives with correct device identity and event ordering after reconnection.
- The receiver continues receiving timestamped samples during steady-state operation.
- The collector reads comparable interface fields from Cisco and non-Cisco devices using supported model paths.
Explanation
Correct Answer
C:Use a periodic telemetry subscription at a measured cadence suitable for trending and capacity planning. Verify the resulting network behavior rather than relying only on the saved configuration.
Incorrect Answers
A:This observation relates to a different topology: An alerting system needs immediate notice of interface administrative status changes but only polls every five minutes. It does not verify the present outcome.
B:This observation relates to a different topology: A security operations service needs authoritative interface state changes, not a dashboard that replays stale telemetry after collector failure. It does not verify the present outcome.
D:This offered choice, “The collector reads comparable interface fields from Cisco and non-Cisco devices using supported model paths”, addresses a separate concern. That option relates to this separate design case: A multivendor enterprise wants one consistent YANG representation for interface operational counters but each platform exposes vendor-specific native trees. It does not answer the current requirement.
Question 394
A 20-Mbps backup link replaces a 200-Mbps primary WAN but the shaper keeps its 200-Mbps limit after failover. Which observed result would most directly prove the design meets the intended goal?
- All essential classes receive their planned treatment without violating actual egress capacity.
- Multicast forwarding resumes on the newly valid upstream with no persistent duplicates.
- A WAN outage still produces actionable diagnostics and authorized operator access.
- Backup traffic stays within the 20-Mbps service rate and critical classes remain usable.
Explanation
Correct Answer
D:Use link-aware QoS policy to update shaping and class allocations for the reduced-capacity backup transport. Verify the resulting network behavior rather than relying only on the saved configuration.
Incorrect Answers
A:This observation relates to a different topology: A switch QoS scheduler guarantees 30% to backup traffic and 80% to voice under full congestion, exceeding possible link capacity. It does not verify the present outcome.
B:This observation relates to a different topology: The RPF interface changes after a unicast route failover, but the multicast router retains stale upstream join state. It does not verify the present outcome.
C:This observation relates to a different topology: Network management of a branch uses a VPN over its sole primary WAN, and the organization reports no way to diagnose a provider outage. It does not verify the present outcome.
Question 395
Multiple campus cores are connected in a full mesh, creating expensive adjacency and troubleshooting overhead. Which observed result would most directly prove the design meets the intended goal?
- External routes and flows remain segmented by approved virtual network.
- Approved intersite traffic carries the expected segmentation context without undesired leakage.
- A single link failure preserves required site connectivity without unnecessary adjacency proliferation.
- Encapsulated end-to-end test packets pass between fabric edges without fragmentation blackholes.
Explanation
Correct Answer
C:Use a topology appropriate to business resilience requirements, such as a structured regional core with redundant distribution paths. Verify the resulting network behavior rather than relying only on the saved configuration.
Incorrect Answers
A:This observation relates to a different topology: A campus has a fabric border but its external firewall cannot distinguish multiple endpoint VNs leaving the fabric. It does not verify the present outcome.
B:This observation relates to a different topology: An organization needs consistent segmentation across two SD-Access fabric sites connected by a routed MPLS service. It does not verify the present outcome.
D:This observation relates to a different topology: Fabric edge nodes encapsulate packets, but the underlay path MTU is too small for added VXLAN overhead. It does not verify the present outcome.
Question 396
A branch OSPF design selects a totally stubby area but an application requires type-3 interarea routes rather than only the default. Which observed result would most directly prove the design meets the intended goal?
- Local access failures generate bounded LSDB changes without disrupting unrelated branches.
- The branch receives the intended interarea destinations and no unwanted external LSAs.
- Bidirectional test prefixes appear once with predictable origin and no repeated reimport after failover.
- Each site advertises unique prefixes and the regional summarization boundary routes traffic to the correct branch.
Explanation
Correct Answer
B:Choose the appropriate stub-area variant or redesign to preserve required interarea summaries. Verify the resulting network behavior rather than relying only on the saved configuration.
Incorrect Answers
A:This observation relates to a different topology: An OSPF deployment puts all 600 remote access switches into area 0 and floods changes to every site. It does not verify the present outcome.
C:This observation relates to a different topology: Branch A and B redistribute external BGP into OSPF, then advertise resulting routes back into BGP at the opposite edge. It does not verify the present outcome.
D:This offered choice, “Each site advertises unique prefixes and the regional summarization boundary routes traffic to the correct branch”, addresses a separate concern. That option relates to this separate design case: A retailer adds 70 branches and reused 10.20.0.0/16 at several sites; the MPLS provider cannot distinguish the overlapping prefixes in the enterprise routing table. It does not answer the current requirement.
Question 397
A city campus needs a 10-Gbps local metro interconnect with SLA and carrier demarcation, but the proposed design assumes standard broadband internet guarantees. Which observed result would most directly prove the design meets the intended goal?
- Voice sessions remain inside the approved quality budget over the constrained backup link.
- Measured throughput and failover meet the contractual envelope across the metro sites.
- The branch establishes the required controlled overlay sessions without depending on unsupported unsolicited inbound access.
- Approved SaaS sessions use the closer permitted breakout and remain governed by the security policy.
Explanation
Correct Answer
B:Evaluate a Metro Ethernet service with committed bandwidth, fault demarcation and suitable Ethernet handoff. Verify the resulting network behavior rather than relying only on the saved configuration.
Incorrect Answers
A:This observation relates to a different topology: A branch has broadband backup with no QoS controls and a voice service drops under failover saturation. It does not verify the present outcome.
C:This observation relates to a different topology: 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 verify the present outcome.
D:This observation relates to a different topology: A retail design directs all cloud SaaS traffic through headquarters even though local internet breakout is allowed and latency is poor. It does not verify the present outcome.
Question 398
A branch QoS policy matches all TCP 443 traffic as video, including large software downloads. Which observed result would most directly prove the design meets the intended goal?
- Packet captures across both sites show correct class markings before and after provider handoff.
- Voice delay stays within SLA during video bursts while other classes retain scheduled service.
- Control-plane adjacencies and monitoring remain stable during representative congestion.
- Only the intended interactive application receives real-time class treatment during a test.
Explanation
Correct Answer
D:Use validated application classification or more precise traffic identity instead of assuming TCP port 443 defines one service. Verify the resulting network behavior rather than relying only on the saved configuration.
Incorrect Answers
A:This observation relates to a different topology: Two sites use different DSCP mappings for the same video stream and one class is downgraded at the carrier boundary. It does not verify the present outcome.
B:This observation relates to a different topology: Video and voice both use one strict-priority queue, causing voice jitter when video surges. It does not verify the present outcome.
C:This observation relates to a different topology: A campus QoS policy gives low priority to routing keepalives and network monitoring, and routing adjacencies flap during congestion. It does not verify the present outcome.
Question 399
Two campus distribution routers each have a single power feed from the same rack PDU, yet the architecture counts them as separate fault domains. Which observed result would most directly prove the design meets the intended goal?
- Clients discover approved printers across subnets without carrying all broadcasts between buildings.
- Both routed uplinks forward to the rest of campus and a link failure reroutes traffic without a campus STP event.
- A tested hardware or supervisor failure meets application recovery objectives without unexpected shared dependencies.
- Loss of either PDU leaves the campus default gateway and upstream traffic operating.
Explanation
Correct Answer
D:Provide independent power infrastructure for each redundant network node and validate dual-path resilience. Verify the resulting network behavior rather than relying only on the saved configuration.
Incorrect Answers
A:This observation relates to a different topology: A campus access layer spans large broadcast domains for print discovery despite an architecture target of small local VLANs. It does not verify the present outcome.
B:This observation relates to a different topology: A routed-access campus needs equal-cost forwarding to two distribution routers while keeping each VLAN local to one wiring closet. It does not verify the present outcome.
C:This observation relates to a different topology: A virtualized distribution pair uses one logical control plane and engineers assume it offers separate failure domains like two chassis in different buildings. It does not verify the present outcome.
Question 400
A branch EIGRP router advertises remote routes back into its hub and occasionally becomes a transit path between hubs. Which observed result would most directly prove the design meets the intended goal?
- Failed-route convergence completes without broad stuck-in-active propagation.
- Clients retain enough independent eligible paths to support the agreed failover policy.
- The optimal successor forwards normally and eligible backup takes over without a network-wide query where feasible.
- Hubs avoid querying through the branch as a transit path and branch-local prefixes remain visible.
Explanation
Correct Answer
D:Configure an appropriate EIGRP stub design on the branch while allowing its locally connected routes to reach the hubs. Verify the resulting network behavior rather than relying only on the saved configuration.
Incorrect Answers
A:This observation relates to a different topology: An EIGRP core has routes stuck active after one WAN path fails and queries spread into many remote sites. It does not verify the present outcome.
B:This observation relates to a different topology: An iBGP route reflector sees several candidate routes to the same destination but advertises only its best path to clients. It does not verify the present outcome.
C:This observation relates to a different topology: A router receives two EIGRP routes for a prefix with different metrics and the design team wants deterministic failover. It does not verify the present outcome.
Designing Cisco Enterprise Networks (ENSLD) (300-420) Practice Tests
