Cisco 350-501 Practice Test 3
Question 20
For an original SPCOR service-provider engineering scenario, consider: A provider wants SRv6 steering but assumes that a classic MPLS node SID and an IPv6 segment endpoint have identical forwarding and encapsulation behavior. Select TWO complementary steps: the targeted correction and its strongest prechange validation.
- Check: Examine IGP SID advertisement, SR policy candidate path, segment list and traceroute or telemetry for both normal and failed links.
- Add an arbitrary segment list with no advertised SIDs and assume every path automatically meets the latency objective.
- Check: Test spoofed and valid sources, check BGP blackhole policy scope and verify MACsec session status and counters on supported links.
- Change: Define the selected SR data plane and explicit policy segments, then verify headend steering, supported SIDs and actual egress path.
- Change: Restrict and police packets destined to the routing control plane, and coordinate authenticated neighbor sessions and supported TTL-security settings.
Explanation
Correct Answer
A:Segment routing encodes forwarding instructions as segments; SR-MPLS labels and SRv6 IPv6 segment identifiers use different data-plane representations. Required intervention: Define the selected SR data plane and explicit policy segments, then verify headend steering, supported SIDs and actual egress path.
D:Segment routing encodes forwarding instructions as segments; SR-MPLS labels and SRv6 IPv6 segment identifiers use different data-plane representations. Evidence: Examine IGP SID advertisement, SR policy candidate path, segment list and traceroute or telemetry for both normal and failed links.
Incorrect Answers
B:For this select two assessment, the shortcut changes or bypasses the necessary routing, service or operational boundary rather than correcting it. Applied case: A provider wants SRv6 steering but assumes that a classic MPLS node SID and an IPv6 segment endpoint have identical forwarding and encapsulation behavior.
C:Check: Test spoofed and valid sources, check BGP blackhole policy scope and verify MACsec session status and counters on supported links. Segment routing encodes forwarding instructions as segments; SR-MPLS labels and SRv6 IPv6 segment identifiers use different data-plane representations.
E:Change: Restrict and police packets destined to the routing control plane, and coordinate authenticated neighbor sessions and supported TTL-security settings. Segment routing encodes forwarding instructions as segments; SR-MPLS labels and SRv6 IPv6 segment identifiers use different data-plane representations.
Question 21
A service provider network engineer is reviewing this backbone or customer-service scenario: A regional operator needs long-haul fiber capacity between core routers but proposes cable-modem DOCSIS as a direct substitute for DWDM wavelength transport. A proposed shortcut is: Connect an optical line terminal to a DOCSIS coaxial segment and assume connector fit alone creates protocol compatibility. What should the service provider engineer recommend as the narrowly scoped correction? Select ONE best answer.
- Place each split RAN function and its xHaul link deliberately, enforcing the transport latency, timing and reliability needs for the selected functional split.
- Select and consistently implement the intended MPLS QoS tunneling model with explicit ingress classification and egress treatment.
- Match the physical access or transport technology to the fiber plant, sharing model, reach and capacity requirements before choosing optics or termination equipment.
- Connect an optical line terminal to a DOCSIS coaxial segment and assume connector fit alone creates protocol compatibility.
Explanation
Correct Answer
C:This targeted action addresses the observed service-provider control or forwarding gap without discarding necessary controls. Applied case: A regional operator needs long-haul fiber capacity between core routers but proposes cable-modem DOCSIS as a direct substitute for DWDM wavelength transport.
Incorrect Answers
A:Place each split RAN function and its xHaul link deliberately, enforcing the transport latency, timing and reliability needs for the selected functional split. DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems.
B:Select and consistently implement the intended MPLS QoS tunneling model with explicit ingress classification and egress treatment. DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems.
D:DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems. For this best change assessment, the shortcut changes or bypasses the necessary routing, service or operational boundary rather than correcting it.
Question 22
A Cisco service provider design review finds: A regional operator needs long-haul fiber capacity between core routers but proposes cable-modem DOCSIS as a direct substitute for DWDM wavelength transport. The team proposes: Match the physical access or transport technology to the fiber plant, sharing model, reach and capacity requirements before choosing optics or termination equipment. 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.
- uRPF checks source reachability, RTBH can discard selected routed traffic during attacks and MACsec protects appropriate Ethernet links; none is interchangeable.
- LPTS and CoPP protect route-processor traffic, while BGP TTL security and authentication restrict unauthorized control sessions when configured consistently.
- DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems.
Explanation
Correct Answer
D:Demonstrable success requires: Each access or backbone circuit uses compatible physical technology and operates within verified loss and throughput limits. Applied case: A regional operator needs long-haul fiber capacity between core routers but proposes cable-modem DOCSIS as a direct substitute for DWDM wavelength transport.
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. DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems.
B:URPF checks source reachability, RTBH can discard selected routed traffic during attacks and MACsec protects appropriate Ethernet links; none is interchangeable. DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems.
C:LPTS and CoPP protect route-processor traffic, while BGP TTL security and authentication restrict unauthorized control sessions when configured consistently. DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems.
Question 23
The service provider operations team has not yet approved a change. Current evidence indicates: A regional operator needs long-haul fiber capacity between core routers but proposes cable-modem DOCSIS as a direct substitute for DWDM wavelength transport. Which evidence best tests the technical diagnosis before approving a disruptive change? Select ONE best answer.
- Review span attenuation, termination equipment, optical power budget, splitter ratio and supported service rates in a documented link plan.
- Inspect received DSCP distributions, policer counters, class queue drops and reservation availability on a link saturation test.
- Examine IGP SID advertisement, SR policy candidate path, segment list and traceroute or telemetry for both normal and failed links.
- Confirm exact software release, target command hierarchy, candidate diff, commit outcome and rollback in a lab device.
Explanation
Correct Answer
A:DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems. Applied case: A regional operator needs long-haul fiber capacity between core routers but proposes cable-modem DOCSIS as a direct substitute for DWDM wavelength transport.
Incorrect Answers
B:Inspect received DSCP distributions, policer counters, class queue drops and reservation availability on a link saturation test. DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems.
C:Examine IGP SID advertisement, SR policy candidate path, segment list and traceroute or telemetry for both normal and failed links. DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems.
D:Confirm exact software release, target command hierarchy, candidate diff, commit outcome and rollback in a lab device. DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems.
Question 24
A candidate correction has been tested and the platform team requires a post-change acceptance check. Original problem: A regional operator needs long-haul fiber capacity between core routers but proposes cable-modem DOCSIS as a direct substitute for DWDM wavelength transport. 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.
- Real-time traffic receives policy-compliant treatment while untrusted markings cannot starve other paid service classes.
- Changes are accepted only through supported platform mechanisms and an invalid candidate does not silently alter unrelated service state.
- Routed optical ports establish stable links within their documented performance limits and exposed errors are monitored.
- Each access or backbone circuit uses compatible physical technology and operates within verified loss and throughput limits.
Explanation
Correct Answer
D:DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems. The result must be validated using the documented device, service or access context.
Incorrect Answers
A:Real-time traffic receives policy-compliant treatment while untrusted markings cannot starve other paid service classes. DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems.
B:Changes are accepted only through supported platform mechanisms and an invalid candidate does not silently alter unrelated service state. DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems.
C:Routed optical ports establish stable links within their documented performance limits and exposed errors are monitored. DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems.
Question 25
An implementation sign-off request identifies the following problem: A regional operator needs long-haul fiber capacity between core routers but proposes cable-modem DOCSIS as a direct substitute for DWDM wavelength transport. Which paired technical change and validation should close the implementation review? Select ONE best answer.
- Change: Restrict and police packets destined to the routing control plane, and coordinate authenticated neighbor sessions and supported TTL-security settings. Verify: Inspect control-plane counters, BGP session state and authentication or TTL error logs during permitted and denied test connections.
- Change: Size and isolate NFVI compute, networking and storage resources for each VNF or container workload and validate orchestration and availability. Verify: Benchmark representative packet rates, CPU pinning or acceleration, virtual NIC queues, failure recovery and privilege boundaries.
- Change: Match the physical access or transport technology to the fiber plant, sharing model, reach and capacity requirements before choosing optics or termination equipment. Verify: Review span attenuation, termination equipment, optical power budget, splitter ratio and supported service rates in a documented link plan.
- 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.
Explanation
Correct Answer
C:DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems. The change is successful only when: Each access or backbone circuit uses compatible physical technology and operates within verified loss and throughput limits.
Incorrect Answers
A:Change: Restrict and police packets destined to the routing control plane, and coordinate authenticated neighbor sessions and supported TTL-security settings. DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems.
B:Change: Size and isolate NFVI compute, networking and storage resources for each VNF or container workload and validate orchestration and availability. DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems.
D: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.
Question 26
A service provider network engineer is reviewing this backbone or customer-service scenario: A broadband access project uses passive optical splitters yet the design assumes every home has a dedicated point-to-point dark fiber to the central office. A proposed shortcut is: Connect an optical line terminal to a DOCSIS coaxial segment and assume connector fit alone creates protocol compatibility. What should the service provider engineer recommend as the narrowly scoped correction? Select ONE best answer.
- Restrict and police packets destined to the routing control plane, and coordinate authenticated neighbor sessions and supported TTL-security settings.
- Match the physical access or transport technology to the fiber plant, sharing model, reach and capacity requirements before choosing optics or termination equipment.
- Connect an optical line terminal to a DOCSIS coaxial segment and assume connector fit alone creates protocol compatibility.
- Apply source validation or ACL policy at the correct ingress, coordinate RTBH only for approved attack targets and enable link-layer encryption where required.
Explanation
Correct Answer
B:This targeted action addresses the observed service-provider control or forwarding gap without discarding necessary controls. DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems.
Incorrect Answers
A:Restrict and police packets destined to the routing control plane, and coordinate authenticated neighbor sessions and supported TTL-security settings. DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems.
C:DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems. Use this instead: Match the physical access or transport technology to the fiber plant, sharing model, reach and capacity requirements before choosing optics or termination equipment.
D:Apply source validation or ACL policy at the correct ingress, coordinate RTBH only for approved attack targets and enable link-layer encryption where required. DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems.
Question 27
A Cisco service provider design review finds: A broadband access project uses passive optical splitters yet the design assumes every home has a dedicated point-to-point dark fiber to the central office. The team proposes: Match the physical access or transport technology to the fiber plant, sharing model, reach and capacity requirements before choosing optics or termination equipment. Which engineering principle most strongly supports the recommended response? Select ONE best answer.
- 5G RAN functional splits determine where RU DU and CU processing occurs; their transport interfaces have distinct capacity, timing and latency requirements.
- Network functions can be virtualized as VM or container workloads, but packet throughput and security depend on reserved resources and supported host interfaces.
- DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems.
- Service provider QoS must enforce customer trust and admission limits; DS-TE reservation models affect how traffic-class bandwidth can be shared or protected.
Explanation
Correct Answer
C:Demonstrable success requires: Each access or backbone circuit uses compatible physical technology and operates within verified loss and throughput limits. This principle explains the proposed technical approach, which is: Match the physical access or transport technology to the fiber plant, sharing model, reach and capacity requirements before choosing optics or termination equipment.
Incorrect Answers
A:5G RAN functional splits determine where RU DU and CU processing occurs; their transport interfaces have distinct capacity, timing and latency requirements. DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems.
B:Network functions can be virtualized as VM or container workloads, but packet throughput and security depend on reserved resources and supported host interfaces. DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems.
D: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.
Question 28
The service provider operations team has not yet approved a change. Current evidence indicates: A broadband access project uses passive optical splitters yet the design assumes every home has a dedicated point-to-point dark fiber to the central office. 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.
- Review span attenuation, termination equipment, optical power budget, splitter ratio and supported service rates in a documented link plan.
- Inspect control-plane counters, BGP session state and authentication or TTL error logs during permitted and denied test connections.
- Benchmark representative packet rates, CPU pinning or acceleration, virtual NIC queues, failure recovery and privilege boundaries.
Explanation
Correct Answer
B:DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems. Confirm afterward that: Each access or backbone circuit uses compatible physical technology and operates within verified loss and throughput limits.
Incorrect Answers
A:Capture customer DSCP, MPLS traffic class at ingress and transit, and egress queue or remark behavior under controlled congestion. DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems.
C:Inspect control-plane counters, BGP session state and authentication or TTL error logs during permitted and denied test connections. DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems.
D:Benchmark representative packet rates, CPU pinning or acceleration, virtual NIC queues, failure recovery and privilege boundaries. DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems.
Question 29
A candidate correction has been tested and the platform team requires a post-change acceptance check. Original problem: A broadband access project uses passive optical splitters yet the design assumes every home has a dedicated point-to-point dark fiber to the central office. 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.
- Legitimate neighbors remain established and malicious control-plane floods cannot exhaust the router CPU at configured limits.
- Changes are accepted only through supported platform mechanisms and an invalid candidate does not silently alter unrelated service state.
- Each access or backbone circuit uses compatible physical technology and operates within verified loss and throughput limits.
- Measured traffic follows the intended policy when valid and a known fallback occurs if a segment becomes unreachable.
Explanation
Correct Answer
C:DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems. Applied case: A broadband access project uses passive optical splitters yet the design assumes every home has a dedicated point-to-point dark fiber to the central office.
Incorrect Answers
A:Legitimate neighbors remain established and malicious control-plane floods cannot exhaust the router CPU at configured limits. DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems.
B:Changes are accepted only through supported platform mechanisms and an invalid candidate does not silently alter unrelated service state. A broadband access project uses passive optical splitters yet the design assumes every home has a dedicated point-to-point dark fiber to the central office.
D:Measured traffic follows the intended policy when valid and a known fallback occurs if a segment becomes unreachable. DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems.
Question 30
For an original SPCOR service-provider engineering scenario, consider: A broadband access project uses passive optical splitters yet the design assumes every home has a dedicated point-to-point dark fiber to the central office. Select TWO complementary steps: the targeted correction and its strongest prechange validation.
- Change: Match the physical access or transport technology to the fiber plant, sharing model, reach and capacity requirements before choosing optics or termination equipment.
- Connect an optical line terminal to a DOCSIS coaxial segment and assume connector fit alone creates protocol compatibility.
- Check: Inspect control-plane counters, BGP session state and authentication or TTL error logs during permitted and denied test connections.
- Check: Review span attenuation, termination equipment, optical power budget, splitter ratio and supported service rates in a documented link plan.
- Change: Validate coherent optic capabilities, router support, fiber reach and link optical telemetry before enabling routed optical connectivity.
Explanation
Correct Answer
A:DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems. Acceptance: Each access or backbone circuit uses compatible physical technology and operates within verified loss and throughput limits.
D:DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems. Required intervention: Match the physical access or transport technology to the fiber plant, sharing model, reach and capacity requirements before choosing optics or termination equipment.
Incorrect Answers
B:For this select two assessment, the shortcut changes or bypasses the necessary routing, service or operational boundary rather than correcting it. DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems.
C:Check: Inspect control-plane counters, BGP session state and authentication or TTL error logs during permitted and denied test connections. DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems.
E:Change: Validate coherent optic capabilities, router support, fiber reach and link optical telemetry before enabling routed optical connectivity. DWDM multiplexes wavelength channels over fiber while xPON shares passive optical distribution and DOCSIS and xDSL use distinct access media and systems.
