Question 130
A central campus migration introduces SD-Access but existing campus users still depend on a shared DHCP and DNS service outside the fabric. The proposed remedy is: Route approved shared services through the fabric handoff with correct helper/service reachability and policy. Which observation would most directly confirm that remedy works as intended?
- Check the endpoint registration and map resolution to the correct fabric edge RLOC.
- Inspect endpoint attachment on the edge and VXLAN forwarding toward the selected remote RLOC.
- Verify legacy endpoint reachability through the handoff without unapproved cross-VN traffic.
- Confirm a new fabric endpoint receives DHCP and resolves DNS via the approved external service.
Explanation
Correct Answer
D:The decisive acceptance observation is: Confirm a new fabric endpoint receives DHCP and resolves DNS via the approved external service. This tests the working mechanism, while the original incident was: new fabric devices get APIPA/no lease while static-IP devices reach the fabric gateway.
Incorrect Answers
A:This test measures a different behavior: Check the endpoint registration and map resolution to the correct fabric edge RLOC. It does not establish the target outcome. For the documented fault, the direct acceptance test is: confirm a new fabric endpoint receives DHCP and resolves DNS via the approved external service.
B:This test measures a different behavior: Inspect endpoint attachment on the edge and VXLAN forwarding toward the selected remote RLOC. It does not establish the target outcome. For the documented fault, the direct acceptance test is: confirm a new fabric endpoint receives DHCP and resolves DNS via the approved external service.
C:This test measures a different behavior: Verify legacy endpoint reachability through the handoff without unapproved cross-VN traffic. It does not establish the target outcome. For the documented fault, the direct acceptance test is: confirm a new fabric endpoint receives DHCP and resolves DNS via the approved external service.
Question 131
A central campus migration introduces SD-Access but existing campus users still depend on a shared DHCP and DNS service outside the fabric. During troubleshooting: New fabric devices get APIPA/no lease while static-IP devices reach the fabric gateway. Which underlying cause best explains the recorded behavior?
- Its EID-to-RLOC registration is missing or incorrect in the fabric control plane.
- The access switch was not functioning as an SD-Access fabric edge for that VLAN/virtual network.
- The migration handoff and fabric border integration were omitted.
- The required external DHCP relay or policy path was not integrated for migrated fabric endpoints.
Explanation
Correct Answer
D:The actual technical cause is: The required external DHCP relay or policy path was not integrated for migrated fabric endpoints. It specifically explains the observation: new fabric devices get APIPA/no lease while static-IP devices reach the fabric gateway. The correcting configuration is: route approved shared services through the fabric handoff with correct helper/service reachability and policy.
Incorrect Answers
A:That diagnosis is supported by a different symptom: An endpoint is reachable on its local edge but remote fabric edges cannot resolve its current location. Here the recorded observation is: new fabric devices get APIPA/no lease while static-IP devices reach the fabric gateway. The applicable cause is: the required external DHCP relay or policy path was not integrated for migrated fabric endpoints.
B:That diagnosis is supported by a different symptom: Remote traffic is bridged out an ordinary trunk rather than encapsulated through the fabric overlay. Here the recorded observation is: new fabric devices get APIPA/no lease while static-IP devices reach the fabric gateway. The applicable cause is: the required external DHCP relay or policy path was not integrated for migrated fabric endpoints.
C:That diagnosis is supported by a different symptom: An unconverted legacy VLAN has no communication path to allowed fabric services. Here the recorded observation is: new fabric devices get APIPA/no lease while static-IP devices reach the fabric gateway. The applicable cause is: the required external DHCP relay or policy path was not integrated for migrated fabric endpoints.
Question 132
A central campus migration introduces SD-Access but existing campus users still depend on a shared DHCP and DNS service outside the fabric. The initial change is: Route approved shared services through the fabric handoff with correct helper/service reachability and policy. Which continuing control most directly prevents a recurrence of the documented problem: New fabric devices get APIPA/no lease while static-IP devices reach the fabric gateway.
- Monitor endpoint registrations after moves and ensure fabric control-plane redundancy.
- Validate edge onboarding, VN assignments and overlay reachability in fabric provisioning.
- Test identity/segmentation and essential services for every migrated user subnet.
- Keep legacy/fabric handoff addresses, VLANs, routes and policy boundaries in migration tests.
Explanation
Correct Answer
C:The continuing protective control is: Test identity/segmentation and essential services for every migrated user subnet. This addresses the underlying failure mechanism: the required external DHCP relay or policy path was not integrated for migrated fabric endpoints. The corresponding operational check is: confirm a new fabric endpoint receives DHCP and resolves DNS via the approved external service.
Incorrect Answers
A:That control reduces a separate risk: Its EID-to-RLOC registration is missing or incorrect in the fabric control plane. For the described design, the recurring risk arises from: the required external DHCP relay or policy path was not integrated for migrated fabric endpoints. The specific required safeguard is: test identity/segmentation and essential services for every migrated user subnet.
B:That control reduces a separate risk: The access switch was not functioning as an SD-Access fabric edge for that VLAN/virtual network. For the described design, the recurring risk arises from: the required external DHCP relay or policy path was not integrated for migrated fabric endpoints. The specific required safeguard is: test identity/segmentation and essential services for every migrated user subnet.
D:That control reduces a separate risk: The migration handoff and fabric border integration were omitted. For the described design, the recurring risk arises from: the required external DHCP relay or policy path was not integrated for migrated fabric endpoints. The specific required safeguard is: test identity/segmentation and essential services for every migrated user subnet.
Question 133
Two QoS classes share a WAN link, and business policy assigns minimum bandwidth to transactional data without giving it strict priority. The incident evidence is: Business transactions lose throughput when the default class consumes the entire congested WAN queue. Which targeted configuration or design change best addresses the failure?
- Use output shaping toward the contracted rate to buffer bursts rather than relying on carrier discard.
- Interpret the class bandwidth share and apply suitable class-based weighted fair queuing for the intended minimum service.
- Match trusted voice traffic into an appropriate QoS class and apply the intended service policy at the congested interface.
- Apply a suitable policer with explicit conform/exceed actions to the guest class at the intended interface.
Explanation
Correct Answer
B:The required correction is: Interpret the class bandwidth share and apply suitable class-based weighted fair queuing for the intended minimum service. The underlying failure mechanism is: The class has no effective bandwidth reservation or policy is not active on the egress interface. Verify success by carrying out this direct test: under congestion, verify transactional class service stays above its intended share without starving other classes.
Incorrect Answers
A:Using output shaping toward the contracted rate to buffer bursts rather than relying on carrier discard would not interpret the class bandwidth share and apply suitable class-based weighted fair queuing for the intended minimum service.
C:Matching trusted voice traffic into an appropriate QoS class and applying the intended service policy at the congested interface would not interpret the class bandwidth share and apply suitable class-based weighted fair queuing for the intended minimum service.
D:Applying a suitable policer with explicit conform/exceed actions to the guest class at the intended interface would not interpret the class bandwidth share and apply suitable class-based weighted fair queuing for the intended minimum service.
Question 134
Two QoS classes share a WAN link, and business policy assigns minimum bandwidth to transactional data without giving it strict priority. The proposed remedy is: Interpret the class bandwidth share and apply suitable class-based weighted fair queuing for the intended minimum service. Which observation would most directly confirm that remedy works as intended?
- Observe local shaping queue depth and lowered carrier drop counters under controlled offered load.
- Compare conform/exceed counters and confirm out-of-profile packets follow the documented drop or remark action.
- Under congestion, verify transactional class service stays above its intended share without starving other classes.
- Check class-map counters rise for the voice flow and verify queue service with simultaneous bulk traffic.
Explanation
Correct Answer
C:The decisive acceptance observation is: Under congestion, verify transactional class service stays above its intended share without starving other classes. This tests the working mechanism, while the original incident was: business transactions lose throughput when the default class consumes the entire congested WAN queue.
Incorrect Answers
A:This test measures a different behavior: Observe local shaping queue depth and lowered carrier drop counters under controlled offered load. It does not establish the target outcome. For the documented fault, the direct acceptance test is: under congestion, verify transactional class service stays above its intended share without starving other classes.
B:This test measures a different behavior: Compare conform/exceed counters and confirm out-of-profile packets follow the documented drop or remark action. It does not establish the target outcome. For the documented fault, the direct acceptance test is: under congestion, verify transactional class service stays above its intended share without starving other classes.
D:This test measures a different behavior: Check class-map counters rise for the voice flow and verify queue service with simultaneous bulk traffic. It does not establish the target outcome. For the documented fault, the direct acceptance test is: under congestion, verify transactional class service stays above its intended share without starving other classes.
Question 135
Two QoS classes share a WAN link, and business policy assigns minimum bandwidth to transactional data without giving it strict priority. During troubleshooting: Business transactions lose throughput when the default class consumes the entire congested WAN queue. Which underlying cause best explains the recorded behavior?
- The QoS class match never identified the voice packets, so the priority action was never used.
- Unshaped output bursts exceed the provider's committed service rate.
- The policer does not match the guest class or is applied at the wrong traffic direction.
- The class has no effective bandwidth reservation or policy is not active on the egress interface.
Explanation
Correct Answer
D:The actual technical cause is: The class has no effective bandwidth reservation or policy is not active on the egress interface. It specifically explains the observation: business transactions lose throughput when the default class consumes the entire congested WAN queue. The correcting configuration is: interpret the class bandwidth share and apply suitable class-based weighted fair queuing for the intended minimum service.
Incorrect Answers
A:That diagnosis is supported by a different symptom: Voice traffic enters the default class even though a strict-priority queue exists. Here the recorded observation is: business transactions lose throughput when the default class consumes the entire congested WAN queue. The applicable cause is: the class has no effective bandwidth reservation or policy is not active on the egress interface.
B:That diagnosis is supported by a different symptom: Provider discard counters increase during bursts even though average utilization appears within contract. Here the recorded observation is: business transactions lose throughput when the default class consumes the entire congested WAN queue. The applicable cause is: the class has no effective bandwidth reservation or policy is not active on the egress interface.
C:That diagnosis is supported by a different symptom: Guest bursts continue consuming uplink capacity despite a configured threshold in an unrelated class. Here the recorded observation is: business transactions lose throughput when the default class consumes the entire congested WAN queue. The applicable cause is: the class has no effective bandwidth reservation or policy is not active on the egress interface.
Question 136
A bank virtualizes production routers on dedicated compute nodes and must avoid an intervening host operating system between the hypervisor and physical server. The incident evidence is: The proposal relies on a workstation application that starts only after Windows boots and calls it a bare-metal hypervisor. Which targeted configuration or design change best addresses the failure?
- Attach the vNICs to an appropriate virtual switch/port group on the host.
- Use a hosted Type 2 hypervisor appropriate for laptop-based experiments rather than claiming bare-metal architecture.
- Align virtual port-group VLAN tagging and physical uplink 802.1Q trunk permitted VLANs.
- Choose a Type 1 bare-metal hypervisor to directly manage physical hardware and hosted VMs.
Explanation
Correct Answer
D:The required correction is: Choose a Type 1 bare-metal hypervisor to directly manage physical hardware and hosted VMs. The underlying failure mechanism is: The solution is a hosted Type 2 hypervisor dependent on the general-purpose host OS. Verify success by carrying out this direct test: inspect the hypervisor deployment and confirm no separate desktop host OS mediates its hardware access.
Incorrect Answers
A:Attaching the vNICs to an appropriate virtual switch/port group on the host would not meet the need for a Type 1 bare-metal hypervisor to directly manage physical hardware and hosted VMs.
B:Using a hosted Type 2 hypervisor appropriate for laptop-based experiments rather than claiming bare-metal architecture would not meet the need for a Type 1 bare-metal hypervisor to directly manage physical hardware and hosted VMs.
C:Aligning virtual port-group VLAN tagging and physical uplink 802.1Q trunk permitted VLANs would not meet the need for a Type 1 bare-metal hypervisor to directly manage physical hardware and hosted VMs.
Question 137
A bank virtualizes production routers on dedicated compute nodes and must avoid an intervening host operating system between the hypervisor and physical server. The proposed remedy is: Choose a Type 1 bare-metal hypervisor to directly manage physical hardware and hosted VMs. Which observation would most directly confirm that remedy works as intended?
- Verify the virtualization process runs on top of the user's installed host OS and creates isolated guest VMs.
- Capture east-west frames on the virtual switch and verify no physical-uplink transit is required for local guests.
- Verify tagged VLAN traffic across virtual and physical switch boundaries.
- Inspect the hypervisor deployment and confirm no separate desktop host OS mediates its hardware access.
Explanation
Correct Answer
D:The decisive acceptance observation is: Inspect the hypervisor deployment and confirm no separate desktop host OS mediates its hardware access. This tests the working mechanism, while the original incident was: the proposal relies on a workstation application that starts only after Windows boots and calls it a bare-metal hypervisor.
Incorrect Answers
A:This test measures a different behavior: Verify the virtualization process runs on top of the user's installed host OS and creates isolated guest VMs. It does not establish the target outcome. For the documented fault, the direct acceptance test is: inspect the hypervisor deployment and confirm no separate desktop host OS mediates its hardware access.
B:This test measures a different behavior: Capture east-west frames on the virtual switch and verify no physical-uplink transit is required for local guests. It does not establish the target outcome. For the documented fault, the direct acceptance test is: inspect the hypervisor deployment and confirm no separate desktop host OS mediates its hardware access.
C:This test measures a different behavior: Verify tagged VLAN traffic across virtual and physical switch boundaries. It does not establish the target outcome. For the documented fault, the direct acceptance test is: inspect the hypervisor deployment and confirm no separate desktop host OS mediates its hardware access.
Question 138
A bank virtualizes production routers on dedicated compute nodes and must avoid an intervening host operating system between the hypervisor and physical server. During troubleshooting: The proposal relies on a workstation application that starts only after Windows boots and calls it a bare-metal hypervisor. Which underlying cause best explains the recorded behavior?
- The solution is a hosted Type 2 hypervisor dependent on the general-purpose host OS.
- The outer hypervisor did not expose required virtualization extensions to the nested hypervisor.
- Their virtual NICs attach to different isolated virtual switches or port groups.
- The physical uplink trunk or virtual port-group VLAN mapping excludes VLAN 120.
Explanation
Correct Answer
A:The actual technical cause is: The solution is a hosted Type 2 hypervisor dependent on the general-purpose host OS. It specifically explains the observation: the proposal relies on a workstation application that starts only after Windows boots and calls it a bare-metal hypervisor. The correcting configuration is: choose a Type 1 bare-metal hypervisor to directly manage physical hardware and hosted VMs.
Incorrect Answers
B:That diagnosis is supported by a different symptom: Second-level virtual routers report hardware-assisted virtualization unavailable. Here the recorded observation is: the proposal relies on a workstation application that starts only after Windows boots and calls it a bare-metal hypervisor. The applicable cause is: the solution is a hosted Type 2 hypervisor dependent on the general-purpose host OS.
C:That diagnosis is supported by a different symptom: Two guests in separate isolated virtual networks cannot ARP for one another despite using the same physical host. Here the recorded observation is: the proposal relies on a workstation application that starts only after Windows boots and calls it a bare-metal hypervisor. The applicable cause is: the solution is a hosted Type 2 hypervisor dependent on the general-purpose host OS.
D:That diagnosis is supported by a different symptom: VMs on VLAN 120 communicate internally but cannot reach external devices on VLAN 120. Here the recorded observation is: the proposal relies on a workstation application that starts only after Windows boots and calls it a bare-metal hypervisor. The applicable cause is: the solution is a hosted Type 2 hypervisor dependent on the general-purpose host OS.
Question 139
A bank virtualizes production routers on dedicated compute nodes and must avoid an intervening host operating system between the hypervisor and physical server. The initial change is: Choose a Type 1 bare-metal hypervisor to directly manage physical hardware and hosted VMs. Which continuing control most directly prevents a recurrence of the documented problem: The proposal relies on a workstation application that starts only after Windows boots and calls it a bare-metal hypervisor.
- Document the difference between development-only hosted virtualization and production bare-metal hosts.
- Verify virtual-switch port-group membership and VLAN isolation after VM migrations.
- Validate virtual/physical VLAN mapping together before adding tenant networks.
- Use supported enterprise hypervisor clustering and host update procedures rather than desktop VM assumptions.
Explanation
Correct Answer
D:The continuing protective control is: Use supported enterprise hypervisor clustering and host update procedures rather than desktop VM assumptions. This addresses the underlying failure mechanism: the solution is a hosted Type 2 hypervisor dependent on the general-purpose host OS. The corresponding operational check is: inspect the hypervisor deployment and confirm no separate desktop host OS mediates its hardware access.
Incorrect Answers
A:That control reduces a separate risk: The hypervisor is Type 2 and depends on the underlying host OS lifecycle. For the described design, the recurring risk arises from: the solution is a hosted Type 2 hypervisor dependent on the general-purpose host OS. The specific required safeguard is: use supported enterprise hypervisor clustering and host update procedures rather than desktop VM assumptions.
B:That control reduces a separate risk: Their virtual NICs attach to different isolated virtual switches or port groups. For the described design, the recurring risk arises from: the solution is a hosted Type 2 hypervisor dependent on the general-purpose host OS. The specific required safeguard is: use supported enterprise hypervisor clustering and host update procedures rather than desktop VM assumptions.
C:That control reduces a separate risk: The physical uplink trunk or virtual port-group VLAN mapping excludes VLAN 120. For the described design, the recurring risk arises from: the solution is a hosted Type 2 hypervisor dependent on the general-purpose host OS. The specific required safeguard is: use supported enterprise hypervisor clustering and host update procedures rather than desktop VM assumptions.
Question 140
A developer installs virtualization software inside an existing laptop OS for isolated network automation test VMs. The incident evidence is: A lab VM cannot start until the user's laptop operating system and hosted virtualization application launch. Which targeted configuration or design change best addresses the failure?
- Enable supported nested virtualization/CPU assist exposure where required by the hypervisor and hardware.
- Choose a Type 1 bare-metal hypervisor to directly manage physical hardware and hosted VMs.
- Use a hosted Type 2 hypervisor appropriate for laptop-based experiments rather than claiming bare-metal architecture.
- Create separate guest VMs with allocated vCPUs, memory and virtual NICs managed by the hypervisor.
Explanation
Correct Answer
C:The required correction is: Use a hosted Type 2 hypervisor appropriate for laptop-based experiments rather than claiming bare-metal architecture. The underlying failure mechanism is: The hypervisor is Type 2 and depends on the underlying host OS lifecycle. Verify success by carrying out this direct test: verify the virtualization process runs on top of the user's installed host OS and creates isolated guest VMs.
Incorrect Answers
A:Enabling supported nested virtualization/CPU assist exposure where required by the hypervisor and hardware would not meet the need for a hosted Type 2 hypervisor appropriate for laptop-based experiments rather than claiming bare-metal architecture.
B:Choosing a Type 1 bare-metal hypervisor to directly manage physical hardware and hosted VMs would not meet the need for a hosted Type 2 hypervisor appropriate for laptop-based experiments rather than claiming bare-metal architecture.
D:Creating separate guest VMs with allocated vCPUs, memory and virtual NICs managed by the hypervisor would not meet the need for a hosted Type 2 hypervisor appropriate for laptop-based experiments rather than claiming bare-metal architecture.
Implementing Cisco Enterprise Network Core Technologies (ENCOR) (350-401) Practice Tests