Cisco 350-501 Practice Test 8
Question 70
For an original SPCOR service-provider engineering scenario, consider: A service provider moves a routing application into containers but grants it unrestricted host privileges while omitting lifecycle and failure-domain planning. Select TWO complementary steps: the targeted correction and its strongest prechange validation.
- Change: Apply source validation or ACL policy at the correct ingress, coordinate RTBH only for approved attack targets and enable link-layer encryption where required.
- Deploy every virtual network function with unlimited privileges and no resource accounting because software images have no physical bottlenecks.
- Change: Size and isolate NFVI compute, networking and storage resources for each VNF or container workload and validate orchestration and availability.
- Check: Benchmark representative packet rates, CPU pinning or acceleration, virtual NIC queues, failure recovery and privilege boundaries.
- Check: Map each service endpoint, customer attachment, label-switched path and VPN policy against intended reachability using a two-tenant lab.
Explanation
Correct Answer
C:Network functions can be virtualized as VM or container workloads, but packet throughput and security depend on reserved resources and supported host interfaces. Evidence: Benchmark representative packet rates, CPU pinning or acceleration, virtual NIC queues, failure recovery and privilege boundaries.
D:Network functions can be virtualized as VM or container workloads, but packet throughput and security depend on reserved resources and supported host interfaces. Required intervention: Size and isolate NFVI compute, networking and storage resources for each VNF or container workload and validate orchestration and availability.
Incorrect Answers
A:Change: Apply source validation or ACL policy at the correct ingress, coordinate RTBH only for approved attack targets and enable link-layer encryption where required. Network functions can be virtualized as VM or container workloads, but packet throughput and security depend on reserved resources and supported host interfaces.
B:For this select two assessment, the shortcut changes or bypasses the necessary routing, service or operational boundary rather than correcting it. Network functions can be virtualized as VM or container workloads, but packet throughput and security depend on reserved resources and supported host interfaces.
E:Check: Map each service endpoint, customer attachment, label-switched path and VPN policy against intended reachability using a two-tenant lab. Network functions can be virtualized as VM or container workloads, but packet throughput and security depend on reserved resources and supported host interfaces.
Question 71
A service provider network engineer is reviewing this backbone or customer-service scenario: A PE operator assumes a uniform QoS model yet observes customer IP DSCP unchanged after an MPLS core congestion event and cannot explain EXP traffic class mapping. A proposed shortcut is: Assume MPLS traffic-class and customer IP markings always copy bidirectionally regardless of the chosen tunneling model. What should the service provider engineer recommend as the narrowly scoped correction? Select ONE best answer.
- Size and isolate NFVI compute, networking and storage resources for each VNF or container workload and validate orchestration and availability.
- Establish explicit QoS trust boundaries, bounded class marking and TE reservation policies that match measured capacity and the selected bandwidth model.
- Select and consistently implement the intended MPLS QoS tunneling model with explicit ingress classification and egress treatment.
- Assume MPLS traffic-class and customer IP markings always copy bidirectionally regardless of the chosen tunneling model.
Explanation
Correct Answer
C:This targeted action addresses the observed service-provider control or forwarding gap without discarding necessary controls. Applied case: A PE operator assumes a uniform QoS model yet observes customer IP DSCP unchanged after an MPLS core congestion event and cannot explain EXP traffic class mapping.
Incorrect Answers
A:Size and isolate NFVI compute, networking and storage resources for each VNF or container workload and validate orchestration and availability. Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior.
B:Establish explicit QoS trust boundaries, bounded class marking and TE reservation policies that match measured capacity and the selected bandwidth model. Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior.
D:Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior. For this best change assessment, the shortcut changes or bypasses the necessary routing, service or operational boundary rather than correcting it.
Question 72
A Cisco service provider design review finds: A PE operator assumes a uniform QoS model yet observes customer IP DSCP unchanged after an MPLS core congestion event and cannot explain EXP traffic class mapping. The team proposes: Select and consistently implement the intended MPLS QoS tunneling model with explicit ingress classification and egress treatment. Which engineering principle most strongly supports the recommended response? Select ONE best answer.
- Service provider QoS must enforce customer trust and admission limits; DS-TE reservation models affect how traffic-class bandwidth can be shared or protected.
- DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems.
- IOS XE and IOS XR have distinct software architectures and management workflows; IOS XR supports a transactional configuration commit model.
- Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior.
Explanation
Correct Answer
D:Demonstrable success requires: Marking and scheduling follow the selected model without unintended exposure of one customer's QoS assumptions to another. Applied case: A PE operator assumes a uniform QoS model yet observes customer IP DSCP unchanged after an MPLS core congestion event and cannot explain EXP traffic class mapping.
Incorrect Answers
A:Service provider QoS must enforce customer trust and admission limits; DS-TE reservation models affect how traffic-class bandwidth can be shared or protected. Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior.
B:DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems. Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior.
C:IOS XE and IOS XR have distinct software architectures and management workflows; IOS XR supports a transactional configuration commit model. Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior.
Question 73
The service provider operations team has not yet approved a change. Current evidence indicates: A PE operator assumes a uniform QoS model yet observes customer IP DSCP unchanged after an MPLS core congestion event and cannot explain EXP traffic class mapping. Which evidence best tests the technical diagnosis before approving a disruptive change? Select ONE best answer.
- Map RU DU CU interfaces, packet timing source, loss and delay budgets and measure behavior during a representative congestion window.
- Compare optic part and platform matrix, channel power, error metrics and line-system span data on a controlled pair of links.
- Benchmark representative packet rates, CPU pinning or acceleration, virtual NIC queues, failure recovery and privilege boundaries.
- Capture customer DSCP, MPLS traffic class at ingress and transit, and egress queue or remark behavior under controlled congestion.
Explanation
Correct Answer
D:Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior. Applied case: A PE operator assumes a uniform QoS model yet observes customer IP DSCP unchanged after an MPLS core congestion event and cannot explain EXP traffic class mapping.
Incorrect Answers
A:Map RU DU CU interfaces, packet timing source, loss and delay budgets and measure behavior during a representative congestion window. Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior.
B:Compare optic part and platform matrix, channel power, error metrics and line-system span data on a controlled pair of links. Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior.
C:Benchmark representative packet rates, CPU pinning or acceleration, virtual NIC queues, failure recovery and privilege boundaries. Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior.
Question 74
A candidate correction has been tested and the platform team requires a post-change acceptance check. Original problem: A PE operator assumes a uniform QoS model yet observes customer IP DSCP unchanged after an MPLS core congestion event and cannot explain EXP traffic class mapping. The carrier operations owner needs positive and negative tests showing existing customer services remain available. Which acceptance result demonstrates correct service provider forwarding and control behavior without disrupting authorized workflows? Select ONE best answer.
- Marking and scheduling follow the selected model without unintended exposure of one customer's QoS assumptions to another.
- Spoofed ingress traffic is denied, authorized flows remain, blackholing stays scoped and required Ethernet links are authenticated and encrypted.
- Changes are accepted only through supported platform mechanisms and an invalid candidate does not silently alter unrelated service state.
- Legitimate neighbors remain established and malicious control-plane floods cannot exhaust the router CPU at configured limits.
Explanation
Correct Answer
A:Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior. The result must be validated using the documented device, service or access context.
Incorrect Answers
B:This option addresses a different service provider engineering topic (uRPF RTBH MACsec and data-plane security) rather than the documented MPLS QoS pipe uniform and short-pipe models decision.
C:Changes are accepted only through supported platform mechanisms and an invalid candidate does not silently alter unrelated service state. Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior.
D:Legitimate neighbors remain established and malicious control-plane floods cannot exhaust the router CPU at configured limits. Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior.
Question 75
An implementation sign-off request identifies the following problem: A PE operator assumes a uniform QoS model yet observes customer IP DSCP unchanged after an MPLS core congestion event and cannot explain EXP traffic class mapping. Which paired technical change and validation should close the implementation review? Select ONE best answer.
- Change: Use the target OS configuration model and supported platform syntax, validating candidate changes and rollback behavior before deployment. Verify: Confirm exact software release, target command hierarchy, candidate diff, commit outcome and rollback in a lab device.
- Change: Select a service model matching customer connectivity and use the required MPLS forwarding and VPN control-plane mechanisms rather than treating a transport label as tenant isolation. Verify: Map each service endpoint, customer attachment, label-switched path and VPN policy against intended reachability using a two-tenant lab.
- Change: Select and consistently implement the intended MPLS QoS tunneling model with explicit ingress classification and egress treatment. Verify: Capture customer DSCP, MPLS traffic class at ingress and transit, and egress queue or remark behavior under controlled congestion.
- Change: Place each split RAN function and its xHaul link deliberately, enforcing the transport latency, timing and reliability needs for the selected functional split. Verify: Map RU DU CU interfaces, packet timing source, loss and delay budgets and measure behavior during a representative congestion window.
Explanation
Correct Answer
C:Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior. The change is successful only when: Marking and scheduling follow the selected model without unintended exposure of one customer's QoS assumptions to another.
Incorrect Answers
A:Change: Use the target OS configuration model and supported platform syntax, validating candidate changes and rollback behavior before deployment. Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior.
B:Change: Select a service model matching customer connectivity and use the required MPLS forwarding and VPN control-plane mechanisms rather than treating a transport label as tenant isolation. Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior.
D:Change: Place each split RAN function and its xHaul link deliberately, enforcing the transport latency, timing and reliability needs for the selected functional split. Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior.
Question 76
A service provider network engineer is reviewing this backbone or customer-service scenario: A backbone deploys a short-pipe treatment but mistakenly trusts provider internal MPLS traffic class markings for customer-facing egress scheduling. A proposed shortcut is: Assume MPLS traffic-class and customer IP markings always copy bidirectionally regardless of the chosen tunneling model. What should the service provider engineer recommend as the narrowly scoped correction? Select ONE best answer.
- Assume MPLS traffic-class and customer IP markings always copy bidirectionally regardless of the chosen tunneling model.
- Select and consistently implement the intended MPLS QoS tunneling model with explicit ingress classification and egress treatment.
- Validate coherent optic capabilities, router support, fiber reach and link optical telemetry before enabling routed optical connectivity.
- Use the target OS configuration model and supported platform syntax, validating candidate changes and rollback behavior before deployment.
Explanation
Correct Answer
B:This targeted action addresses the observed service-provider control or forwarding gap without discarding necessary controls. Applied case: A backbone deploys a short-pipe treatment but mistakenly trusts provider internal MPLS traffic class markings for customer-facing egress scheduling.
Incorrect Answers
A:Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior. Applied case: A backbone deploys a short-pipe treatment but mistakenly trusts provider internal MPLS traffic class markings for customer-facing egress scheduling.
C:Validate coherent optic capabilities, router support, fiber reach and link optical telemetry before enabling routed optical connectivity. Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior.
D:Use the target OS configuration model and supported platform syntax, validating candidate changes and rollback behavior before deployment. Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior.
Question 77
A Cisco service provider design review finds: A backbone deploys a short-pipe treatment but mistakenly trusts provider internal MPLS traffic class markings for customer-facing egress scheduling. The team proposes: Select and consistently implement the intended MPLS QoS tunneling model with explicit ingress classification and egress treatment. Which engineering principle most strongly supports the recommended response? Select ONE best answer.
- Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior.
- DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems.
- IOS XE and IOS XR have distinct software architectures and management workflows; IOS XR supports a transactional configuration commit model.
- Metro Ethernet connectivity models define endpoint relationships, while an MPLS transport label steers packets and customer isolation requires a separate service and routing design.
Explanation
Correct Answer
A:Demonstrable success requires: Marking and scheduling follow the selected model without unintended exposure of one customer's QoS assumptions to another. Applied case: A backbone deploys a short-pipe treatment but mistakenly trusts provider internal MPLS traffic class markings for customer-facing egress scheduling.
Incorrect Answers
B:DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems. A backbone deploys a short-pipe treatment but mistakenly trusts provider internal MPLS traffic class markings for customer-facing egress scheduling.
C:IOS XE and IOS XR have distinct software architectures and management workflows; IOS XR supports a transactional configuration commit model. A backbone deploys a short-pipe treatment but mistakenly trusts provider internal MPLS traffic class markings for customer-facing egress scheduling.
D:Metro Ethernet connectivity models define endpoint relationships, while an MPLS transport label steers packets and customer isolation requires a separate service and routing design. Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior.
Question 78
The service provider operations team has not yet approved a change. Current evidence indicates: A backbone deploys a short-pipe treatment but mistakenly trusts provider internal MPLS traffic class markings for customer-facing egress scheduling. Which evidence best tests the technical diagnosis before approving a disruptive change? Select ONE best answer.
- Capture customer DSCP, MPLS traffic class at ingress and transit, and egress queue or remark behavior under controlled congestion.
- Confirm exact software release, target command hierarchy, candidate diff, commit outcome and rollback in a lab device.
- Map RU DU CU interfaces, packet timing source, loss and delay budgets and measure behavior during a representative congestion window.
- Inspect control-plane counters, BGP session state and authentication or TTL error logs during permitted and denied test connections.
Explanation
Correct Answer
A:Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior. Confirm afterward that: Marking and scheduling follow the selected model without unintended exposure of one customer's QoS assumptions to another.
Incorrect Answers
B:Confirm exact software release, target command hierarchy, candidate diff, commit outcome and rollback in a lab device. Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior.
C:Map RU DU CU interfaces, packet timing source, loss and delay budgets and measure behavior during a representative congestion window. Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior.
D:Inspect control-plane counters, BGP session state and authentication or TTL error logs during permitted and denied test connections. Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior.
Question 79
A candidate correction has been tested and the platform team requires a post-change acceptance check. Original problem: A backbone deploys a short-pipe treatment but mistakenly trusts provider internal MPLS traffic class markings for customer-facing egress scheduling. The carrier operations owner needs positive and negative tests showing existing customer services remain available. Which acceptance result demonstrates correct service provider forwarding and control behavior without disrupting authorized workflows? Select ONE best answer.
- Routed optical ports establish stable links within their documented performance limits and exposed errors are monitored.
- Changes are accepted only through supported platform mechanisms and an invalid candidate does not silently alter unrelated service state.
- Marking and scheduling follow the selected model without unintended exposure of one customer's QoS assumptions to another.
- Legitimate neighbors remain established and malicious control-plane floods cannot exhaust the router CPU at configured limits.
Explanation
Correct Answer
C:Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior. The approved implementation step was: Select and consistently implement the intended MPLS QoS tunneling model with explicit ingress classification and egress treatment.
Incorrect Answers
A:Routed optical ports establish stable links within their documented performance limits and exposed errors are monitored. Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior.
B:Changes are accepted only through supported platform mechanisms and an invalid candidate does not silently alter unrelated service state. A backbone deploys a short-pipe treatment but mistakenly trusts provider internal MPLS traffic class markings for customer-facing egress scheduling.
D:Legitimate neighbors remain established and malicious control-plane floods cannot exhaust the router CPU at configured limits. A backbone deploys a short-pipe treatment but mistakenly trusts provider internal MPLS traffic class markings for customer-facing egress scheduling.
Question 80
For an original SPCOR service-provider engineering scenario, consider: A backbone deploys a short-pipe treatment but mistakenly trusts provider internal MPLS traffic class markings for customer-facing egress scheduling. Select TWO complementary steps: the targeted correction and its strongest prechange validation.
- Assume MPLS traffic-class and customer IP markings always copy bidirectionally regardless of the chosen tunneling model.
- Change: Select and consistently implement the intended MPLS QoS tunneling model with explicit ingress classification and egress treatment.
- Check: Examine IGP SID advertisement, SR policy candidate path, segment list and traceroute or telemetry for both normal and failed links.
- Check: Capture customer DSCP, MPLS traffic class at ingress and transit, and egress queue or remark behavior under controlled congestion.
- Change: Size and isolate NFVI compute, networking and storage resources for each VNF or container workload and validate orchestration and availability.
Explanation
Correct Answer
B:Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior. Acceptance: Marking and scheduling follow the selected model without unintended exposure of one customer's QoS assumptions to another.
D:Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior. Required intervention: Select and consistently implement the intended MPLS QoS tunneling model with explicit ingress classification and egress treatment.
Incorrect Answers
A:For this select two assessment, the shortcut changes or bypasses the necessary routing, service or operational boundary rather than correcting it. Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior.
C:Check: Examine IGP SID advertisement, SR policy candidate path, segment list and traceroute or telemetry for both normal and failed links. Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior.
E:Change: Size and isolate NFVI compute, networking and storage resources for each VNF or container workload and validate orchestration and availability. Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior.
