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Question 760
A wireless access-point refresh increases PoE needs above the available 802.3at class on older switches. The chosen correction is: Specify access switch PoE capabilities and power budget that support the APs' required negotiated power levels. Which additional predeployment check is most relevant?
- Review platform compatibility and perform a maintenance-window failover test before promising hitless service.
- Compare model-specific power requirements with cable loss and redundant supply capacity.
- Verify platform multi-chassis capability and fate sharing before bundling cross-chassis links.
- Validate WLC and AP fabric roles against platform support and target mobility scope.
Explanation
Correct Answer
B:Compare model-specific power requirements with cable loss and redundant supply capacity. This protects the intended outcome: Each AP enables its intended radio features at full load without power denial or downshift.
Incorrect Answers
A:That precaution belongs to another scenario: A remote campus uses two distribution switches and requires nonstop gateway access during a planned supervisor replacement. It is not the primary safeguard for this rollout.
C:That precaution belongs to another scenario: Multiple access switches connect to one distribution block through independent Layer 2 uplinks with a blocked redundant path. It is not the primary safeguard for this rollout.
D:That precaution belongs to another scenario: A fabric site needs a guest wireless SSID without extending the guest Layer 2 domain across the whole enterprise. It is not the primary safeguard for this rollout.
Question 761
A partner BGP session accidentally advertises a sensitive 10.0.0.0/8 internal route to an external ASN. The chosen correction is: Apply a scoped outbound prefix filter that blocks private/internal routes from the external BGP adjacency. Which additional predeployment check is most relevant?
- Trace route origin and affected prefix reachability before removing the advertisement.
- Compare active specifics with the aggregate and identify valid exception routes before withdrawal.
- Check metric mapping and tagging consistently at both redistribution routers.
- Verify the resulting advertised-route set from the partner-facing perspective.
Explanation
Correct Answer
D:Verify the resulting advertised-route set from the partner-facing perspective. This protects the intended outcome: Peer-received advertisements exclude the protected prefix while approved public routes remain.
Incorrect Answers
A:That precaution belongs to another scenario: A branch engineer redistributes a static default route into EIGRP and advertises it to every site, overriding the intended hub defaults. It is not the primary safeguard for this rollout.
B:That precaution belongs to another scenario: A campus advertises a /18 summary into the WAN but has no route for one constituent /24 after a building is decommissioned. It is not the primary safeguard for this rollout.
C:That precaution belongs to another scenario: IS-IS adjacencies form between distribution switches, but all internal prefixes are redistributed from OSPF without loop prevention. It is not the primary safeguard for this rollout.
Question 762
A routing telemetry client assumes every operational counter supports on-change updates and receives no updates on one platform. The chosen correction is: Select subscription modes according to the actual leaf and device support, using periodic for counters when necessary. Which additional predeployment check is most relevant?
- Baseline byte rates, memory and packet loss before enabling subscriptions on all devices.
- Validate encoding negotiation and representative samples before broad deployment.
- Query capability/model support and document fallback sampling per platform.
- Measure aggregation accuracy after downsampling before changing alert thresholds.
Explanation
Correct Answer
C:Query capability/model support and document fallback sampling per platform. This protects the intended outcome: The receiver obtains the expected measurement updates for every required signal.
Incorrect Answers
A:That precaution belongs to another scenario: A fleet telemetry design streams all available operational leaves every second over a constrained management link. It is not the primary safeguard for this rollout.
B:That precaution belongs to another scenario: A telemetry receiver supports gRPC but cannot decode the device's gNMI JSON_IETF path data and classifies every update as malformed. It is not the primary safeguard for this rollout.
D:That precaution belongs to another scenario: A global WAN telemetry system publishes a complete 10,000-interface snapshot every 100 ms although the target is only five-minute capacity planning. It is not the primary safeguard for this rollout.
Question 763
A WAN team assumes DWDM wavelength multiplexing itself supplies packet-level route isolation between tenants. The chosen correction is: Separate optical multiplexing requirements from routing or Ethernet tenant segmentation carried over the wavelengths. Which additional predeployment check is most relevant?
- Validate SIM/APN addressing and tunnel establishment from each cellular provider.
- Trace encryption and tenant isolation needs at the service layer before activating capacity.
- Verify encapsulation overhead, security associations, and multicast reachability separately.
- Test management and control outages independently with application probes.
Explanation
Correct Answer
B:Trace encryption and tenant isolation needs at the service layer before activating capacity. This protects the intended outcome: Services over the optical circuit remain isolated by the appropriate higher-layer controls.
Incorrect Answers
A:That precaution belongs to another 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 is not the primary safeguard for this rollout.
C:That precaution belongs to another scenario: A lab requires a routed overlay carrying multicast between sites but encryption is not part of the GRE service itself. It is not the primary safeguard for this rollout.
D:That precaution belongs to another scenario: A multisite SD-WAN deployment uses one manager for configuration and assumes manager reachability is necessary for every packet of user data. It is not the primary safeguard for this rollout.
Question 764
A campus uses DSCP EF for voice signaling, voice media, and backup traffic, causing priority queue overload. The chosen correction is: Classify traffic by actual application need and reserve EF treatment for suitable expedited traffic. Which additional predeployment check is most relevant?
- Include control, default, and scavenger classes when totaling reserved bandwidth.
- Validate queue allocation and the actual contracted CIR during saturation tests.
- Audit markings at endpoint, access and WAN boundaries before rewriting application policies.
- Size the priority class and verify congestion behavior with realistic mixes.
Explanation
Correct Answer
C:Audit markings at endpoint, access and WAN boundaries before rewriting application policies. This protects the intended outcome: Priority queuing protects genuine voice media while backup traffic no longer occupies the strict-priority class.
Incorrect Answers
A:That precaution belongs to another scenario: A switch QoS scheduler guarantees 30% to backup traffic and 80% to voice under full congestion, exceeding possible link capacity. It is not the primary safeguard for this rollout.
B:That precaution belongs to another scenario: A branch uses a shaper on voice and bulk traffic together, and the business assumes shaping guarantees that voice always transmits first. It is not the primary safeguard for this rollout.
D:That precaution belongs to another scenario: Video and voice both use one strict-priority queue, causing voice jitter when video surges. It is not the primary safeguard for this rollout.
Question 765
Two campus VRRP gateways both claim master after their shared advertisement path is partitioned, and clients receive inconsistent ARP responses. The chosen correction is: Correct VRRP group identity, priorities, advertisement reachability, and L2 path consistency. Which additional predeployment check is most relevant?
- Test master election with both links present and under a single-failure condition.
- Validate tracking thresholds and the backup's independent upstream path with a controlled failure.
- Validate management and service reachability for each VRF separately.
- Audit the specific-prefix RIB/FIB at source and destination before moving the aggregate.
Explanation
Correct Answer
A:Test master election with both links present and under a single-failure condition. This protects the intended outcome: Exactly one intended master serves the virtual gateway in stable conditions and transitions during failure.
Incorrect Answers
B:That precaution belongs to another scenario: HSRP gateways remain reachable locally after their active router loses the only routed upstream uplink. It is not the primary safeguard for this rollout.
C:That precaution belongs to another scenario: A public safety campus requires independent operations from a corporate tenant even when both use the same distribution hardware. It is not the primary safeguard for this rollout.
D:That precaution belongs to another scenario: A site cutover retains a withdrawn /24 under an unchanged /20 campus summary and traffic follows an obsolete transit path. It is not the primary safeguard for this rollout.
Question 766
An EIGRP core has routes stuck active after one WAN path fails and queries spread into many remote sites. The chosen correction is: Apply EIGRP summarization, stub boundaries, and reliable connectivity to limit query scope. Which additional predeployment check is most relevant?
- Validate advertised stub route classes and redundancy if the branch has multiple uplinks.
- Review route reachability and summary boundaries before introducing stub behavior.
- Confirm end-to-end payload MTU and vendor hardware support before making both sides match.
- Confirm path diversity at reflectors and ensure no unintended loops or excess table growth.
Explanation
Correct Answer
B:Review route reachability and summary boundaries before introducing stub behavior. This protects the intended outcome: Failed-route convergence completes without broad stuck-in-active propagation.
Incorrect Answers
A:That precaution belongs to another scenario: A branch EIGRP router advertises remote routes back into its hub and occasionally becomes a transit path between hubs. It is not the primary safeguard for this rollout.
C:That precaution belongs to another scenario: Two OSPF neighbors on a routed core link are stuck in EXSTART/EXCHANGE and one endpoint uses an incompatible MTU. It is not the primary safeguard for this rollout.
D:That precaution belongs to another scenario: An iBGP route reflector sees several candidate routes to the same destination but advertises only its best path to clients. It is not the primary safeguard for this rollout.
Question 767
An NSF-capable router pair loses a control-plane process briefly and the design assumes all neighboring routers will preserve forwarding. The chosen correction is: Plan NSF graceful-restart interoperability with compatible neighbors and realistic convergence timeouts. Which additional predeployment check is most relevant?
- Measure control-plane convergence and endpoint mapping age under a controlled node failure.
- Verify map resolution and fabric edge RLOC reachability independently.
- Verify VLAN membership, upstream reachability and failure ownership before activating the virtual address.
- Verify protocol-specific graceful-restart restrictions rather than assuming universal hitlessness.
Explanation
Correct Answer
D:Verify protocol-specific graceful-restart restrictions rather than assuming universal hitlessness. This protects the intended outcome: Neighbor relationships recover while supported forwarding state remains stable during the tested restart.
Incorrect Answers
A:That precaution belongs to another scenario: A fabric control-plane node becomes unavailable and endpoint mobility updates stop at one campus site. It is not the primary safeguard for this rollout.
B:That precaution belongs to another scenario: An SD-Access architect assumes the fabric's LISP control plane transports all user packets like a data-plane tunnel. It is not the primary safeguard for this rollout.
C:This offered choice, “Verify VLAN membership, upstream reachability and failure ownership before activating the virtual address”, addresses a separate concern. That option relates to this separate design case: A building has two independent distribution switches but hosts use the physical IP of one switch as their default gateway. It does not answer the current requirement.
Question 768
A PIM-SM domain has active receivers but no working rendezvous-point reachability for new source registration. The chosen correction is: Design reliable RP placement or supported RP redundancy with consistent mapping. Which additional predeployment check is most relevant?
- Confirm IGMP snooping querier placement and membership timeouts before changing PIM topology.
- Test RP reachability, register and join behavior under single-node failure.
- Consider site-local RP domains and interdomain source discovery needs before redesign.
- Assess RP and MSDP scaling and supported migration alternatives before deployment.
Explanation
Correct Answer
B:Test RP reachability, register and join behavior under single-node failure. This protects the intended outcome: New sources register and receiver joins build the intended multicast distribution tree.
Incorrect Answers
A:That precaution belongs to another scenario: A multicast network has active PIM neighbors but one edge switch suppresses IGMP reports after an access-layer topology change. It is not the primary safeguard for this rollout.
C:That precaution belongs to another scenario: Several PIM-SM sites use a single RP placed across a high-latency WAN and suffer slow source registration after provider reconvergence. It is not the primary safeguard for this rollout.
D:That precaution belongs to another scenario: Two independent PIM-SM domains each use local rendezvous points but remote sources must be discovered across the domains. It is not the primary safeguard for this rollout.
Question 769
A new SD-WAN site has a single edge appliance and single underlay yet is approved as redundant because controllers run in different data centers. The chosen correction is: Provide independent edge and transport paths when required; treat controller redundancy as a separate failure domain. Which additional predeployment check is most relevant?
- Validate serial authorization and certificate lifecycle before production onboarding.
- Review line-system compatibility, service channels and redundancy before selecting wavelengths.
- Verify per-VPN OMP routes, firewall rules and destination reachability during staging.
- Trace the full data path and perform local edge failover testing before approval.
Explanation
Correct Answer
D:Trace the full data path and perform local edge failover testing before approval. This protects the intended outcome: The site retains approved application reachability after losing one WAN edge or carrier path.
Incorrect Answers
A:That precaution belongs to another scenario: A new WAN edge receives a bootstrap but its control connections fail because the certificate trust chain and organization name differ. It is not the primary safeguard for this rollout.
B:That precaution belongs to another scenario: Several data centers need high-capacity optical transport over metropolitan dark fiber without converting each tenant VLAN to an IP tunnel. It is not the primary safeguard for this rollout.
C:That precaution belongs to another scenario: An SD-WAN fabric routes guest traffic into the production VPN because a new edge reused the corporate service VPN identifier. It is not the primary safeguard for this rollout.
Question 770
A campus design requires both distribution uplinks active but the chosen topology uses classic STP on all Layer 2 connections. The chosen correction is: Use a supported multi-chassis EtherChannel or routed-access design to make redundancy active without a spanning-tree loop. Which additional predeployment check is most relevant?
- Review platform compatibility and perform a maintenance-window failover test before promising hitless service.
- Validate LACP partner system IDs and split-brain protection for the chosen solution.
- Capacity-test a complete single-router failure, not only normal steady-state load.
- Verify platform multi-chassis capability and fate sharing before bundling cross-chassis links.
Explanation
Correct Answer
B:Validate LACP partner system IDs and split-brain protection for the chosen solution. This protects the intended outcome: Both paths carry approved traffic and a member failure has no broad STP reconvergence.
Incorrect Answers
A:That precaution belongs to another scenario: A remote campus uses two distribution switches and requires nonstop gateway access during a planned supervisor replacement. It is not the primary safeguard for this rollout.
C:That precaution belongs to another scenario: A campus with several hundred VLANs uses one active HSRP gateway for all VLANs while another distribution router remains mostly idle. It is not the primary safeguard for this rollout.
D:That precaution belongs to another scenario: Multiple access switches connect to one distribution block through independent Layer 2 uplinks with a blocked redundant path. It is not the primary safeguard for this rollout.
Designing Cisco Enterprise Networks (ENSLD) (300-420) Practice Tests
