Cisco 350-501 Practice Test 31
Question 300
For an original SPCOR service-provider engineering scenario, consider: A carrier route traverses a bundle member that failed silently, while long IGP hello timers delay the detection of forwarding loss. Select THREE compatible elements: a proper correction, a targeted diagnostic and an acceptance result.
- Result: Genuine path loss is detected promptly while minor delay variation does not trigger avoidable adjacency resets.
- Result: Stable OSPFv3 adjacencies advertise the intended IPv6 prefixes with reachable next hops.
- Change: Enable compatible path diversity or BGP PIC mechanisms where supported and verify backup data-plane programming before a failure.
- Check: Inspect BGP neighbor transport state, local and remote AS, update source, TCP reachability and IPv4 or IPv6 address-family activation.
- Change: Coordinate BFD with supported routing clients and realistic detect-multiplier and interval settings for stable rapid failure detection.
- Check: Compare BFD session state, negotiated intervals, packet drops and routing convergence after controlled loss and benign congestion tests.
Explanation
Correct Answer
A:BFD detects data-path forwarding failure independently of slower routing hellos but extreme timer settings can create false failures. Required intervention: Coordinate BFD with supported routing clients and realistic detect-multiplier and interval settings for stable rapid failure detection.
E:BFD detects data-path forwarding failure independently of slower routing hellos but extreme timer settings can create false failures. Acceptance: Genuine path loss is detected promptly while minor delay variation does not trigger avoidable adjacency resets.
F:BFD detects data-path forwarding failure independently of slower routing hellos but extreme timer settings can create false failures. Compare BFD session state, negotiated intervals, packet drops and routing convergence after controlled loss and benign congestion tests.
Incorrect Answers
B:Result: Stable OSPFv3 adjacencies advertise the intended IPv6 prefixes with reachable next hops. BFD detects data-path forwarding failure independently of slower routing hellos but extreme timer settings can create false failures.
C:Change: Enable compatible path diversity or BGP PIC mechanisms where supported and verify backup data-plane programming before a failure. BFD detects data-path forwarding failure independently of slower routing hellos but extreme timer settings can create false failures.
D:Check: Inspect BGP neighbor transport state, local and remote AS, update source, TCP reachability and IPv4 or IPv6 address-family activation. BFD detects data-path forwarding failure independently of slower routing hellos but extreme timer settings can create false failures.
Question 301
A service provider network engineer is reviewing this backbone or customer-service scenario: A BGP peer repeatedly flaps because aggressive BFD timing is configured beyond hardware and network jitter capabilities. A proposed shortcut is: Set one-millisecond BFD probes on every congested platform and assume all peers support the timers without negotiation. What should the service provider engineer recommend as the narrowly scoped correction? Select ONE best answer.
- Match IS-IS level operation and interface parameters before expecting LSP exchange and route installation across a service provider core link.
- Set one-millisecond BFD probes on every congested platform and assume all peers support the timers without negotiation.
- Coordinate BFD with supported routing clients and realistic detect-multiplier and interval settings for stable rapid failure detection.
- Deploy route reflection with deliberate client and cluster design and preserve IGP reachability to advertised BGP next hops.
Explanation
Correct Answer
C:This targeted action addresses the observed service-provider control or forwarding gap without discarding necessary controls. Applied case: A BGP peer repeatedly flaps because aggressive BFD timing is configured beyond hardware and network jitter capabilities.
Incorrect Answers
A:Match IS-IS level operation and interface parameters before expecting LSP exchange and route installation across a service provider core link. BFD detects data-path forwarding failure independently of slower routing hellos but extreme timer settings can create false failures.
B:BFD detects data-path forwarding failure independently of slower routing hellos but extreme timer settings can create false failures. Applied case: A BGP peer repeatedly flaps because aggressive BFD timing is configured beyond hardware and network jitter capabilities.
D:Deploy route reflection with deliberate client and cluster design and preserve IGP reachability to advertised BGP next hops. BFD detects data-path forwarding failure independently of slower routing hellos but extreme timer settings can create false failures.
Question 302
A Cisco service provider design review finds: A BGP peer repeatedly flaps because aggressive BFD timing is configured beyond hardware and network jitter capabilities. The team proposes: Coordinate BFD with supported routing clients and realistic detect-multiplier and interval settings for stable rapid failure detection. Which engineering principle most strongly supports the recommended response? Select ONE best answer.
- BFD detects data-path forwarding failure independently of slower routing hellos but extreme timer settings can create false failures.
- OSPF SPF evaluates cumulative link costs, including configured interface cost and supported reference-bandwidth scaling, not geographic distance.
- BGP communities carry policy tags whose meaning depends on configured policy; local preference influences internal outbound selection but is not a universal external traffic-engineering instruction.
- IS-IS NET encodes an area and unique system identifier; Level-1 flooding is area scoped while Level-2 connects interarea backbone reachability.
Explanation
Correct Answer
A:Demonstrable success requires: Genuine path loss is detected promptly while minor delay variation does not trigger avoidable adjacency resets. Applied case: A BGP peer repeatedly flaps because aggressive BFD timing is configured beyond hardware and network jitter capabilities.
Incorrect Answers
B:OSPF SPF evaluates cumulative link costs, including configured interface cost and supported reference-bandwidth scaling, not geographic distance. BFD detects data-path forwarding failure independently of slower routing hellos but extreme timer settings can create false failures.
C:This option addresses a different service provider engineering topic (BGP route-policy communities and provider preference) rather than the documented BFD rapid fault detection and link stability decision.
D:IS-IS NET encodes an area and unique system identifier; Level-1 flooding is area scoped while Level-2 connects interarea backbone reachability. BFD detects data-path forwarding failure independently of slower routing hellos but extreme timer settings can create false failures.
Question 303
The service provider operations team has not yet approved a change. Current evidence indicates: A BGP peer repeatedly flaps because aggressive BFD timing is configured beyond hardware and network jitter capabilities. Which evidence best tests the technical diagnosis before approving a disruptive change? Select ONE best answer.
- Compare BFD session state, negotiated intervals, packet drops and routing convergence after controlled loss and benign congestion tests.
- Trace sample source routes, redistribution policy hits, tags, LSDB or LSP size and resulting RIB changes across both boundaries.
- Check route-reflector client relationships, originator and cluster attributes, BGP next-hop resolution and the RIB versus FIB.
- Inspect member actor and partner state, bundle hashing, counters and traffic distribution under several representative flows.
Explanation
Correct Answer
A:BFD detects data-path forwarding failure independently of slower routing hellos but extreme timer settings can create false failures. Confirm afterward that: Genuine path loss is detected promptly while minor delay variation does not trigger avoidable adjacency resets.
Incorrect Answers
B:Trace sample source routes, redistribution policy hits, tags, LSDB or LSP size and resulting RIB changes across both boundaries. BFD detects data-path forwarding failure independently of slower routing hellos but extreme timer settings can create false failures.
C:Check route-reflector client relationships, originator and cluster attributes, BGP next-hop resolution and the RIB versus FIB. BFD detects data-path forwarding failure independently of slower routing hellos but extreme timer settings can create false failures.
D:Inspect member actor and partner state, bundle hashing, counters and traffic distribution under several representative flows. BFD detects data-path forwarding failure independently of slower routing hellos but extreme timer settings can create false failures.
Question 304
A candidate correction has been tested and the platform team requires a post-change acceptance check. Original problem: A BGP peer repeatedly flaps because aggressive BFD timing is configured beyond hardware and network jitter capabilities. 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.
- Clients receive intended routes without reflection loops and installed paths resolve to reachable transport next hops.
- Genuine path loss is detected promptly while minor delay variation does not trigger avoidable adjacency resets.
- Valid alternate paths are visible and traffic shifts within expected service objectives when the primary next hop fails.
- The preferred transit path wins for documented policy reasons without unexpected route filtering or next-hop failure.
Explanation
Correct Answer
B:BFD detects data-path forwarding failure independently of slower routing hellos but extreme timer settings can create false failures. The approved implementation step was: Coordinate BFD with supported routing clients and realistic detect-multiplier and interval settings for stable rapid failure detection.
Incorrect Answers
A:Clients receive intended routes without reflection loops and installed paths resolve to reachable transport next hops. BFD detects data-path forwarding failure independently of slower routing hellos but extreme timer settings can create false failures.
C:Valid alternate paths are visible and traffic shifts within expected service objectives when the primary next hop fails. BFD detects data-path forwarding failure independently of slower routing hellos but extreme timer settings can create false failures.
D:The preferred transit path wins for documented policy reasons without unexpected route filtering or next-hop failure. BFD detects data-path forwarding failure independently of slower routing hellos but extreme timer settings can create false failures.
Question 305
An implementation sign-off request identifies the following problem: A BGP peer repeatedly flaps because aggressive BFD timing is configured beyond hardware and network jitter capabilities. Which paired technical change and validation should close the implementation review? Select ONE best answer.
- Change: Coordinate BFD with supported routing clients and realistic detect-multiplier and interval settings for stable rapid failure detection. Verify: Compare BFD session state, negotiated intervals, packet drops and routing convergence after controlled loss and benign congestion tests.
- Change: Configure high availability features with supported peer behavior and validate which control and forwarding states are preserved during process or RP failure. Verify: Measure neighbor resets, stale route retention, forwarding counters and route processing after a planned RP switchover.
- Change: Use the platform's supported policy language, explicit prefix sets and match sequencing to permit only intended routes and apply actions at the correct direction. Verify: Evaluate a test table with allowed, denied and boundary prefixes against actual show-policy and BGP advertised-routes evidence.
- Change: Enable compatible path diversity or BGP PIC mechanisms where supported and verify backup data-plane programming before a failure. Verify: Inspect negotiated additional-path capability, backup path RIB and FIB entries and forwarding interruption during simulated failure.
Explanation
Correct Answer
A:BFD detects data-path forwarding failure independently of slower routing hellos but extreme timer settings can create false failures. The change is successful only when: Genuine path loss is detected promptly while minor delay variation does not trigger avoidable adjacency resets.
Incorrect Answers
B:This option addresses a different service provider engineering topic (Graceful restart NSR and maintenance continuity) rather than the documented BFD rapid fault detection and link stability decision.
C:Change: Use the platform's supported policy language, explicit prefix sets and match sequencing to permit only intended routes and apply actions at the correct direction. BFD detects data-path forwarding failure independently of slower routing hellos but extreme timer settings can create false failures.
D:Change: Enable compatible path diversity or BGP PIC mechanisms where supported and verify backup data-plane programming before a failure. A BGP peer repeatedly flaps because aggressive BFD timing is configured beyond hardware and network jitter capabilities.
Question 306
A service provider network engineer is reviewing this backbone or customer-service scenario: A service provider bundles unequal Ethernet members but an operator assumes a single flow automatically uses the sum of all physical link rates. A proposed shortcut is: Bond incompatible switchports without checking LACP and promise one TCP flow can exceed an individual member link rate. What should the service provider engineer recommend as the narrowly scoped correction? Select ONE best answer.
- Bond incompatible switchports without checking LACP and promise one TCP flow can exceed an individual member link rate.
- Coordinate BFD with supported routing clients and realistic detect-multiplier and interval settings for stable rapid failure detection.
- Verify aggregation protocol, member compatibility, hashing expectations and actual active bandwidth before designing redundancy or QoS.
- Enable compatible path diversity or BGP PIC mechanisms where supported and verify backup data-plane programming before a failure.
Explanation
Correct Answer
C:This targeted action addresses the observed service-provider control or forwarding gap without discarding necessary controls. Applied case: A service provider bundles unequal Ethernet members but an operator assumes a single flow automatically uses the sum of all physical link rates.
Incorrect Answers
A:LACP negotiates compatible members into a logical bundle while per-flow hashing commonly keeps a flow on one member to preserve packet order. For this best change assessment, the shortcut changes or bypasses the necessary routing, service or operational boundary rather than correcting it.
B:Coordinate BFD with supported routing clients and realistic detect-multiplier and interval settings for stable rapid failure detection. LACP negotiates compatible members into a logical bundle while per-flow hashing commonly keeps a flow on one member to preserve packet order.
D:This option addresses a different service provider engineering topic (BGP Additional Paths PIC and fast failover) rather than the documented Link aggregation LACP traffic distribution and member health decision.
Question 307
A Cisco service provider design review finds: A service provider bundles unequal Ethernet members but an operator assumes a single flow automatically uses the sum of all physical link rates. The team proposes: Verify aggregation protocol, member compatibility, hashing expectations and actual active bandwidth before designing redundancy or QoS. Which engineering principle most strongly supports the recommended response? Select ONE best answer.
- LACP negotiates compatible members into a logical bundle while per-flow hashing commonly keeps a flow on one member to preserve packet order.
- BGP communities carry policy tags whose meaning depends on configured policy; local preference influences internal outbound selection but is not a universal external traffic-engineering instruction.
- Redistribution changes protocol scope and metrics; uncontrolled mutual redistribution can create loops and excessive IGP state.
- OSPF area types control which LSA classes are accepted while ABRs can summarize routes; a summary may hide unavailable more-specifics if chosen carelessly.
Explanation
Correct Answer
A:Demonstrable success requires: Accepted members forward correctly, aggregate capacity reflects active links and service survives an individual member failure. Applied case: A service provider bundles unequal Ethernet members but an operator assumes a single flow automatically uses the sum of all physical link rates.
Incorrect Answers
B:This option addresses a different service provider engineering topic (BGP route-policy communities and provider preference) rather than the documented Link aggregation LACP traffic distribution and member health decision.
C:Redistribution changes protocol scope and metrics; uncontrolled mutual redistribution can create loops and excessive IGP state. LACP negotiates compatible members into a logical bundle while per-flow hashing commonly keeps a flow on one member to preserve packet order.
D:OSPF area types control which LSA classes are accepted while ABRs can summarize routes; a summary may hide unavailable more-specifics if chosen carelessly. LACP negotiates compatible members into a logical bundle while per-flow hashing commonly keeps a flow on one member to preserve packet order.
Question 308
The service provider operations team has not yet approved a change. Current evidence indicates: A service provider bundles unequal Ethernet members but an operator assumes a single flow automatically uses the sum of all physical link rates. Which evidence best tests the technical diagnosis before approving a disruptive change? Select ONE best answer.
- Evaluate a test table with allowed, denied and boundary prefixes against actual show-policy and BGP advertised-routes evidence.
- Inspect member actor and partner state, bundle hashing, counters and traffic distribution under several representative flows.
- Compare BFD session state, negotiated intervals, packet drops and routing convergence after controlled loss and benign congestion tests.
- Examine advertised route attributes per peer, remote looking-glass paths and measured ingress flows before and after the change.
Explanation
Correct Answer
B:LACP negotiates compatible members into a logical bundle while per-flow hashing commonly keeps a flow on one member to preserve packet order. Applied case: A service provider bundles unequal Ethernet members but an operator assumes a single flow automatically uses the sum of all physical link rates.
Incorrect Answers
A:Evaluate a test table with allowed, denied and boundary prefixes against actual show-policy and BGP advertised-routes evidence. LACP negotiates compatible members into a logical bundle while per-flow hashing commonly keeps a flow on one member to preserve packet order.
C:Compare BFD session state, negotiated intervals, packet drops and routing convergence after controlled loss and benign congestion tests. LACP negotiates compatible members into a logical bundle while per-flow hashing commonly keeps a flow on one member to preserve packet order.
D:Examine advertised route attributes per peer, remote looking-glass paths and measured ingress flows before and after the change. LACP negotiates compatible members into a logical bundle while per-flow hashing commonly keeps a flow on one member to preserve packet order.
Question 309
A candidate correction has been tested and the platform team requires a post-change acceptance check. Original problem: A service provider bundles unequal Ethernet members but an operator assumes a single flow automatically uses the sum of all physical link rates. 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.
- Accepted members forward correctly, aggregate capacity reflects active links and service survives an individual member failure.
- Expected neighbors reach the appropriate full adjacency state and exchange synchronized LSDB information without hidden MTU mismatches.
- Clients receive intended routes without reflection loops and installed paths resolve to reachable transport next hops.
- Both address families receive valid advertised next hops for the chosen topology mode and failures are diagnosed per family.
Explanation
Correct Answer
A:LACP negotiates compatible members into a logical bundle while per-flow hashing commonly keeps a flow on one member to preserve packet order. 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 (OSPFv2 neighbor state and MTU mismatch) rather than the documented Link aggregation LACP traffic distribution and member health decision.
C:Clients receive intended routes without reflection loops and installed paths resolve to reachable transport next hops. LACP negotiates compatible members into a logical bundle while per-flow hashing commonly keeps a flow on one member to preserve packet order.
D:Both address families receive valid advertised next hops for the chosen topology mode and failures are diagnosed per family. LACP negotiates compatible members into a logical bundle while per-flow hashing commonly keeps a flow on one member to preserve packet order.
Question 310
For an original SPCOR service-provider engineering scenario, consider: A service provider bundles unequal Ethernet members but an operator assumes a single flow automatically uses the sum of all physical link rates. Select TWO complementary steps: the targeted correction and its strongest prechange validation.
- Change: Verify aggregation protocol, member compatibility, hashing expectations and actual active bandwidth before designing redundancy or QoS.
- Change: Align peer AS, transport source, addressing, family activation and supported eBGP hop reachability for the actual topology.
- Check: Evaluate a test table with allowed, denied and boundary prefixes against actual show-policy and BGP advertised-routes evidence.
- Check: Inspect member actor and partner state, bundle hashing, counters and traffic distribution under several representative flows.
- Bond incompatible switchports without checking LACP and promise one TCP flow can exceed an individual member link rate.
Explanation
Correct Answer
A:LACP negotiates compatible members into a logical bundle while per-flow hashing commonly keeps a flow on one member to preserve packet order. Evidence: Inspect member actor and partner state, bundle hashing, counters and traffic distribution under several representative flows.
D:LACP negotiates compatible members into a logical bundle while per-flow hashing commonly keeps a flow on one member to preserve packet order. Required intervention: Verify aggregation protocol, member compatibility, hashing expectations and actual active bandwidth before designing redundancy or QoS.
Incorrect Answers
B:Change: Align peer AS, transport source, addressing, family activation and supported eBGP hop reachability for the actual topology. LACP negotiates compatible members into a logical bundle while per-flow hashing commonly keeps a flow on one member to preserve packet order.
C:Check: Evaluate a test table with allowed, denied and boundary prefixes against actual show-policy and BGP advertised-routes evidence. LACP negotiates compatible members into a logical bundle while per-flow hashing commonly keeps a flow on one member to preserve packet order.
E:For this select two assessment, the shortcut changes or bypasses the necessary routing, service or operational boundary rather than correcting it. LACP negotiates compatible members into a logical bundle while per-flow hashing commonly keeps a flow on one member to preserve packet order.
