Cisco 350-401 Practice Test 1

Question 1

A 900-user campus occupies two adjacent buildings; access switches feed one resilient pair of distribution switches and no separate campus core is needed. The incident evidence is: An access block loses all campus connectivity after one distribution switch fails. Which targeted configuration or design change best addresses the failure?

Plan dual-stack IPv4/IPv6 addressing and forwarding through all relevant native paths, preserving IPv4 delivery for legacy clients and IPv6 routes for dual-stack peers.
Choose a two-tier collapsed-core design with redundant distribution uplinks instead of adding an unnecessary core layer.
Connect each leaf to multiple spines with routed equal-cost reachability and appropriate endpoint routing.
Use a three-tier access, distribution and core architecture to separate campus aggregation from backbone transit.

Explanation

Correct Answer

The required correction is: Choose a two-tier collapsed-core design with redundant distribution uplinks instead of adding an unnecessary core layer. The underlying failure mechanism is: The access block has a single active upstream dependency despite the intended redundant collapsed core. Verify success by carrying out this direct test: check that each access block reaches both distribution peers and an uplink failure preserves upstream reachability.

Incorrect Answers

Planning dual-stack IPv4/IPv6 addressing would not meet the need for collapsed-core distribution design. The access block has a single active upstream dependency despite the intended redundant collapsed core.

Connecting each leaf to multiple spines with routed equal-cost reachability and appropriate endpoint routing would not meet the need for collapsed-core distribution design.

Using a three-tier access, distribution and core architecture to separate campus aggregation from backbone transit would not meet the need for collapsed-core distribution design.

Question 2

A 900-user campus occupies two adjacent buildings; access switches feed one resilient pair of distribution switches and no separate campus core is needed. The proposed remedy is: Choose a two-tier collapsed-core design with redundant distribution uplinks instead of adding an unnecessary core layer. Which observation would most directly confirm that remedy works as intended?

Trace a packet from an access VLAN through its distribution block to a redundant core path without crossing an unrelated access switch.
Test the legacy IPv4-only client against the cloud IPv4 listener and a dual-stack peer against the application IPv6 listener.
Check equal-cost FIB entries and forwarding under loss of one spine-facing link.
Check that each access block reaches both distribution peers and an uplink failure preserves upstream reachability.

Explanation

Correct Answer

The decisive acceptance observation is: Check that each access block reaches both distribution peers and an uplink failure preserves upstream reachability. This tests the working mechanism, while the original incident was: an access block loses all campus connectivity after one distribution switch fails.

Incorrect Answers

This test measures a different behavior: Trace a packet from an access VLAN through its distribution block to a redundant core path without crossing an unrelated access switch. It does not establish the target outcome. For the documented fault, the direct acceptance test is: check that each access block reaches both distribution peers and an uplink failure preserves upstream reachability.

This test measures a different behavior: Test the legacy IPv4-only client against the cloud IPv4 listener and a dual-stack peer against the application IPv6 listener. It does not establish the target outcome. For the documented fault, the direct acceptance test is: check that each access block reaches both distribution peers and an uplink failure preserves upstream reachability.

This test measures a different behavior: Check equal-cost FIB entries and forwarding under loss of one spine-facing link. It does not establish the target outcome. For the documented fault, the direct acceptance test is: check that each access block reaches both distribution peers and an uplink failure preserves upstream reachability.

Question 3

A 900-user campus occupies two adjacent buildings; access switches feed one resilient pair of distribution switches and no separate campus core is needed. During troubleshooting: An access block loses all campus connectivity after one distribution switch fails. Which underlying cause best explains the recorded behavior?

IPv6 addresses or routes are missing on at least one required hop; IPv4 reachability does not automatically deliver IPv6 traffic.
The intended core transit tier was omitted, producing accidental distribution-to-distribution dependence.
The access block has a single active upstream dependency despite the intended redundant collapsed core.
The leaf has a single spine failure domain instead of independent fabric uplinks.

Explanation

Correct Answer

The actual technical cause is: The access block has a single active upstream dependency despite the intended redundant collapsed core. It specifically explains the observation: an access block loses all campus connectivity after one distribution switch fails. The correcting configuration is: choose a two-tier collapsed-core design with redundant distribution uplinks instead of adding an unnecessary core layer.

Incorrect Answers

That diagnosis is supported by a different symptom: IPv4-only clients work, but IPv6-capable hosts fail to reach the dual-stack cloud service over IPv6. Here the recorded observation is: an access block loses all campus connectivity after one distribution switch fails. The applicable cause is: the access block has a single active upstream dependency despite the intended redundant collapsed core.

That diagnosis is supported by a different symptom: A new distribution block must transit another distribution switch to reach remote buildings. Here the recorded observation is: an access block loses all campus connectivity after one distribution switch fails. The applicable cause is: the access block has a single active upstream dependency despite the intended redundant collapsed core.

That diagnosis is supported by a different symptom: A fabric leaf isolates attached workloads whenever its sole spine-facing physical uplink fails. Here the recorded observation is: an access block loses all campus connectivity after one distribution switch fails. The applicable cause is: the access block has a single active upstream dependency despite the intended redundant collapsed core.

Question 4

A 900-user campus occupies two adjacent buildings; access switches feed one resilient pair of distribution switches and no separate campus core is needed. The initial change is: Choose a two-tier collapsed-core design with redundant distribution uplinks instead of adding an unnecessary core layer. Which continuing control most directly prevents a recurrence of the documented problem: An access block loses all campus connectivity after one distribution switch fails.

Preserve distribution-to-core dual homing and avoid making the core terminate ordinary end-user access ports.
Verify all leaves have the required spine adjacencies and symmetric route reachability.
Validate IPv4 and IPv6 reachability and security policies independently after routing or cloud network changes.
Review redundant upstream physical paths and device failure domains whenever access blocks expand.

Explanation

Correct Answer

The continuing protective control is: Review redundant upstream physical paths and device failure domains whenever access blocks expand. This addresses the underlying failure mechanism: the access block has a single active upstream dependency despite the intended redundant collapsed core. The corresponding operational check is: check that each access block reaches both distribution peers and an uplink failure preserves upstream reachability.

Incorrect Answers

That control reduces a separate risk: The intended core transit tier was omitted, producing accidental distribution-to-distribution dependence. For the described design, the recurring risk arises from: the access block has a single active upstream dependency despite the intended redundant collapsed core. The specific required safeguard is: review redundant upstream physical paths and device failure domains whenever access blocks expand.

That control reduces a separate risk: The leaf has a single spine failure domain instead of independent fabric uplinks. For the described design, the recurring risk arises from: the access block has a single active upstream dependency despite the intended redundant collapsed core. The specific required safeguard is: review redundant upstream physical paths and device failure domains whenever access blocks expand.

That control reduces a separate risk: IPv6 addresses or routes are missing on at least one required hop; IPv4 reachability does not automatically deliver IPv6 traffic. For the described design, the recurring risk arises from: the access block has a single active upstream dependency despite the intended redundant collapsed core. The specific required safeguard is: review redundant upstream physical paths and device failure domains whenever access blocks expand.

Question 5

A multi-building university needs independent access, policy aggregation, and high-speed backbone functions with growth across many distribution blocks. The incident evidence is: A new distribution block must transit another distribution switch to reach remote buildings. Which targeted configuration or design change best addresses the failure?

Connect each leaf to multiple spines with routed equal-cost reachability and appropriate endpoint routing.
Choose a two-tier collapsed-core design with redundant distribution uplinks instead of adding an unnecessary core layer.
Place uplinks across independent forwarding or chassis failure domains instead of assuming cable count equals redundancy.
Use a three-tier access, distribution and core architecture to separate campus aggregation from backbone transit.

Explanation

Correct Answer

The required correction is: Use a three-tier access, distribution and core architecture to separate campus aggregation from backbone transit. The underlying failure mechanism is: The intended core transit tier was omitted, producing accidental distribution-to-distribution dependence. Verify success by carrying out this direct test: trace a packet from an access VLAN through its distribution block to a redundant core path without crossing an unrelated access switch.

Incorrect Answers

Connecting each leaf to multiple spines with routed equal-cost reachability and appropriate endpoint routing would not meet the need for adding a separate campus core tier.

Choosing a two-tier collapsed-core design with redundant distribution uplinks would not meet the need for adding a separate campus core tier.

Placing uplinks across independent forwarding or chassis failure domains would not meet the need for adding a separate campus core tier.

Question 6

A multi-building university needs independent access, policy aggregation, and high-speed backbone functions with growth across many distribution blocks. The proposed remedy is: Use a three-tier access, distribution and core architecture to separate campus aggregation from backbone transit. Which observation would most directly confirm that remedy works as intended?

Inspect physical device and slot assignments and disable one forwarding component to check whether a second path survives.
Trace a packet from an access VLAN through its distribution block to a redundant core path without crossing an unrelated access switch.
Check equal-cost FIB entries and forwarding under loss of one spine-facing link.
Check that each access block reaches both distribution peers and an uplink failure preserves upstream reachability.

Explanation

Correct Answer

The decisive acceptance observation is: Trace a packet from an access VLAN through its distribution block to a redundant core path without crossing an unrelated access switch. This tests the working mechanism, while the original incident was: a new distribution block must transit another distribution switch to reach remote buildings.

Incorrect Answers

This test measures a different behavior: Inspect physical device and slot assignments and disable one forwarding component to check whether a second path survives. It does not establish the target outcome. For the documented fault, the direct acceptance test is: trace a packet from an access VLAN through its distribution block to a redundant core path without crossing an unrelated access switch.

This test measures a different behavior: Check equal-cost FIB entries and forwarding under loss of one spine-facing link. It does not establish the target outcome. For the documented fault, the direct acceptance test is: trace a packet from an access VLAN through its distribution block to a redundant core path without crossing an unrelated access switch.

This test measures a different behavior: Check that each access block reaches both distribution peers and an uplink failure preserves upstream reachability. It does not establish the target outcome. For the documented fault, the direct acceptance test is: trace a packet from an access VLAN through its distribution block to a redundant core path without crossing an unrelated access switch.

Question 7

A multi-building university needs independent access, policy aggregation, and high-speed backbone functions with growth across many distribution blocks. During troubleshooting: A new distribution block must transit another distribution switch to reach remote buildings. Which underlying cause best explains the recorded behavior?

The access block has a single active upstream dependency despite the intended redundant collapsed core.
The leaf has a single spine failure domain instead of independent fabric uplinks.
The intended core transit tier was omitted, producing accidental distribution-to-distribution dependence.
The redundant cabling did not remove the common upstream hardware failure domain.

Explanation

Correct Answer

The actual technical cause is: The intended core transit tier was omitted, producing accidental distribution-to-distribution dependence. It specifically explains the observation: a new distribution block must transit another distribution switch to reach remote buildings. The correcting configuration is: use a three-tier access, distribution and core architecture to separate campus aggregation from backbone transit.

Incorrect Answers

That diagnosis is supported by a different symptom: An access block loses all campus connectivity after one distribution switch fails. Here the recorded observation is: a new distribution block must transit another distribution switch to reach remote buildings. The applicable cause is: the intended core transit tier was omitted, producing accidental distribution-to-distribution dependence.

That diagnosis is supported by a different symptom: A fabric leaf isolates attached workloads whenever its sole spine-facing physical uplink fails. Here the recorded observation is: a new distribution block must transit another distribution switch to reach remote buildings. The applicable cause is: the intended core transit tier was omitted, producing accidental distribution-to-distribution dependence.

That diagnosis is supported by a different symptom: Both logical uplinks fail when a single supervisor/line-card component is removed. Here the recorded observation is: a new distribution block must transit another distribution switch to reach remote buildings. The applicable cause is: the intended core transit tier was omitted, producing accidental distribution-to-distribution dependence.

Question 8

A multi-building university needs independent access, policy aggregation, and high-speed backbone functions with growth across many distribution blocks. Select TWO complementary decisions: the direct technical remedy and a safeguard against recurrence. A verification-only step cannot substitute for either action.

Choose a two-tier collapsed-core design with redundant distribution uplinks instead of adding an unnecessary core layer.
Verify all leaves have the required spine adjacencies and symmetric route reachability.
Use a three-tier access, distribution and core architecture to separate campus aggregation from backbone transit.
Plan dual-stack IPv4/IPv6 addressing and forwarding through all relevant native paths, preserving IPv4 delivery for legacy clients and IPv6 routes for dual-stack peers.
Preserve distribution-to-core dual homing and avoid making the core terminate ordinary end-user access ports.

Explanation

Correct Answers

The continuing protective control is: Preserve distribution-to-core dual homing and avoid making the core terminate ordinary end-user access ports. This addresses the underlying failure mechanism: the intended core transit tier was omitted, producing accidental distribution-to-distribution dependence. The corresponding operational check is: trace a packet from an access VLAN through its distribution block to a redundant core path without crossing an unrelated access switch.

Incorrect Answers

A collapsed-core layout does not provide the independent core transit tier this growing multi-building campus requires.

That control reduces a separate risk: The leaf has a single spine failure domain instead of independent fabric uplinks. For the described design, the recurring risk arises from: the intended core transit tier was omitted, producing accidental distribution-to-distribution dependence. The specific required safeguard is: preserve distribution-to-core dual homing and avoid making the core terminate ordinary end-user access ports.

Dual-stack addressing supports IPv4 and IPv6 transport, but it does not establish the separate campus core and distribution functions in the question.

Question 9

A campus access switch has two diverse distribution uplinks but both cables terminate on the same line card in one chassis. The incident evidence is: Both logical uplinks fail when a single supervisor/line-card component is removed. Which targeted configuration or design change best addresses the failure?

Deploy a supported FHRP virtual gateway with correctly coordinated member roles and interface reachability.
Choose a two-tier collapsed-core design with redundant distribution uplinks instead of adding an unnecessary core layer.
Place uplinks across independent forwarding or chassis failure domains instead of assuming cable count equals redundancy.
Use platform-supported stateful switchover with synchronized standby-supervisor state and compatible software.

Explanation

Correct Answer

The required correction is: Place uplinks across independent forwarding or chassis failure domains instead of assuming cable count equals redundancy. The underlying failure mechanism is: The redundant cabling did not remove the common upstream hardware failure domain. Verify success by carrying out this direct test: inspect physical device and slot assignments and disable one forwarding component to check whether a second path survives.

Incorrect Answers

Deploying a supported FHRP virtual gateway with correctly coordinated member roles and interface reachability would not place uplinks across independent forwarding or chassis failure domains.

Choosing a two-tier collapsed-core design with redundant distribution uplinks would not place uplinks across independent forwarding or chassis failure domains.

Using platform-supported stateful switchover with synchronized standby-supervisor state and compatible software would not place uplinks across independent forwarding or chassis failure domains.

Question 10

A campus access switch has two diverse distribution uplinks but both cables terminate on the same line card in one chassis. The proposed remedy is: Place uplinks across independent forwarding or chassis failure domains instead of assuming cable count equals redundancy. Which observation would most directly confirm that remedy works as intended?

Check that each access block reaches both distribution peers and an uplink failure preserves upstream reachability.
Inspect standby readiness and verify routes and interfaces remain operational through a supported switchover test.
Inspect physical device and slot assignments and disable one forwarding component to check whether a second path survives.
Observe the virtual gateway ownership move and successful client traffic when the active gateway loses LAN reachability.

Explanation

Correct Answer

The decisive acceptance observation is: Inspect physical device and slot assignments and disable one forwarding component to check whether a second path survives. This tests the working mechanism, while the original incident was: both logical uplinks fail when a single supervisor/line-card component is removed.

Incorrect Answers

This test measures a different behavior: Check that each access block reaches both distribution peers and an uplink failure preserves upstream reachability. It does not establish the target outcome. For the documented fault, the direct acceptance test is: inspect physical device and slot assignments and disable one forwarding component to check whether a second path survives.

This test measures a different behavior: Inspect standby readiness and verify routes and interfaces remain operational through a supported switchover test. It does not establish the target outcome. For the documented fault, the direct acceptance test is: inspect physical device and slot assignments and disable one forwarding component to check whether a second path survives.

This test measures a different behavior: Observe the virtual gateway ownership move and successful client traffic when the active gateway loses LAN reachability. It does not establish the target outcome. For the documented fault, the direct acceptance test is: inspect physical device and slot assignments and disable one forwarding component to check whether a second path survives.