Cisco CCNP 350-401 ENCOR 802.1Q Trunking and EtherChannel Troubleshooting Practice Test 3

 

Topic 06 Practice Test 3 covers 802.1Q Trunking and EtherChannel Troubleshooting for Cisco 350-401 ENCOR. For broader exam preparation, review the Cisco 350-401 ENCOR Exam Dumps. Every option includes focused technical reasoning explaining both the Cisco enterprise networking concept and its fit to the scenario.

Question 1

An infrastructure engineer is correcting a production condition. The objective is to select the configuration that guarantees a trunk comes up even when the adjacent appliance does not speak DTP. Which option should be implemented? Choose ONE.

802. static 802.1Q trunk mode
803. static EtherChannel on mode
804. switchport nonegotiate
805. restore required VLAN on the trunk

Correct Answer(s)

 

A

Rationale

802. Select static 802.1Q trunk mode for an administratively forced trunk. The stem makes the requirement explicit: select the configuration that guarantees a trunk comes up even when the adjacent appliance does not speak DTP. That result is governed by this trunk mode mechanism rather than by the neighboring options. This makes static 802.1Q trunk mode the direct fit for this case.
803. Static EtherChannel on mode targets a protocol-free static EtherChannel, so it fits another static aggregation condition. The question requires the team to select the configuration that guarantees a trunk comes up even when the adjacent appliance does not speak DTP. Since static 802.1Q trunk mode produces the needed behavior, this choice would not fix the root requirement.
804. Switchport nonegotiate controls a trunk that does not send DTP and is useful for DTP suppression work. This case requires the team to select the configuration that guarantees a trunk comes up even when the adjacent appliance does not speak DTP. Because static 802.1Q trunk mode supplies that behavior, this option acts on the wrong requirement.
805. Restore required VLAN on the trunk should not be changed for this issue; it provides targeted restoration of the missing VLAN for trunk VLAN filtering cases. The actual requirement is to select the configuration that guarantees a trunk comes up even when the adjacent appliance does not speak DTP, which is handled by static 802.1Q trunk mode.

 

Question 2

A campus engineer is preparing a controlled change. The requirement is to verify the parameter most likely to explain native-VLAN warning messages and untagged traffic leakage. Which choice most directly satisfies that requirement? Choose ONE.

1. correct access VLAN assignment
2. consistent EtherChannel member parameters
3. static 802.1Q trunk mode
4. matching native VLAN

Correct Answer(s)

 

D

Rationale

1. Correct access VLAN assignment does not match the evidence because it provides placement of an endpoint in the intended VLAN. That is a access-port VLAN function, whereas the stem requires engineers to verify the parameter most likely to explain native-VLAN warning messages and untagged traffic leakage. matching native VLAN is the option tied to that task.
2. Consistent EtherChannel member parameters has a different role: it supplies compatible member-link configuration in bundle consistency scenarios. The engineer must verify the parameter most likely to explain native-VLAN warning messages and untagged traffic leakage here. That makes matching native VLAN the direct answer and this option unsuitable.
3. Static 802.1Q trunk mode would leave the key condition unchanged because it supplies an administratively forced trunk. That is useful for trunk mode tasks, while this scenario requires the team to verify the parameter most likely to explain native-VLAN warning messages and untagged traffic leakage using matching native VLAN.
4. Matching native VLAN is appropriate because the result is consistent handling of untagged frames. The scenario requires engineers to verify the parameter most likely to explain native-VLAN warning messages and untagged traffic leakage. This feature controls that trunk VLAN consistency behavior specifically, so it is the best fit. This makes matching native VLAN the direct fit for this case.

 

Question 3

An enterprise switch change is being peer-reviewed. The design must choose the narrowest control for allowing VLANs 10, 30, and 50 while excluding other VLANs from the trunk. Which option should be approved? Choose ONE.

1. port-channel logical interface configuration
2. allowed VLAN list
3. LACP active mode
4. matching native VLAN

Correct Answer(s)

 

B

Rationale

1. Port-channel logical interface configuration lacks the needed control effect; it provides consistent aggregate-level configuration for port-channel configuration situations. Here the team must choose the narrowest control for allowing VLANs 10, 30, and 50 while excluding other VLANs from the trunk, which allowed VLAN list enables directly.
2. Choose allowed VLAN list because its result is forwarding of the required VLAN on the trunk. The stem requires the team to choose the narrowest control for allowing VLANs 10, 30, and 50 while excluding other VLANs from the trunk. That is a direct trunk VLAN filtering match, not merely a related feature. This makes allowed VLAN list the direct fit for this case.
3. LACP active mode would be useful when active standards-based EtherChannel negotiation is needed for LACP negotiation work. This question instead asks the team to choose the narrowest control for allowing VLANs 10, 30, and 50 while excluding other VLANs from the trunk. The correct control is allowed VLAN list, so this alternative fails scenario fit.
4. Matching native VLAN controls consistent handling of untagged frames and is useful for trunk VLAN consistency work. This case requires the team to choose the narrowest control for allowing VLANs 10, 30, and 50 while excluding other VLANs from the trunk. Because allowed VLAN list supplies that behavior, this option acts on the wrong requirement.

 

Question 4

A post-change check found a specific production issue. The engineer now needs to select the DTP state that originates negotiation rather than waiting for the peer. Which choice best resolves it? Choose ONE.

1. show etherchannel summary
2. allowed VLAN list
3. DTP dynamic desirable
4. LACP passive mode

Correct Answer(s)

 

C

Rationale

1. Show etherchannel summary is plausible because it delivers direct EtherChannel membership verification for EtherChannel verification cases. Here the team must select the DTP state that originates negotiation rather than waiting for the peer. DTP dynamic desirable directly controls that state, while this option does not.
2. Allowed VLAN list does not match the evidence because it provides forwarding of the required VLAN on the trunk. That is a trunk VLAN filtering function, whereas the stem requires engineers to select the DTP state that originates negotiation rather than waiting for the peer. DTP dynamic desirable is the option tied to that task.
3. DTP dynamic desirable directly produces active DTP trunk negotiation. That is relevant because the team needs to select the DTP state that originates negotiation rather than waiting for the peer. For this DTP negotiation decision, the feature changes the condition identified by the evidence. This makes DTP dynamic desirable the direct fit for this case.
4. LACP passive mode would be an unnecessary change because it controls passive standards-based EtherChannel participation. That is relevant to LACP negotiation requirements, while the current task is to select the DTP state that originates negotiation rather than waiting for the peer using DTP dynamic desirable.

 

Question 5

An infrastructure engineer is correcting a production condition. The objective is to select the DTP state that waits for a neighbor to initiate a trunk proposal. Which option should be implemented? Choose ONE.

1. PAgP desirable mode
2. correct channel-group protocol pairing
3. DTP dynamic desirable
4. DTP dynamic auto

Correct Answer(s)

 

D

Rationale

1. PAgP desirable mode solves a different problem by providing active PAgP EtherChannel negotiation. That matters for PAgP negotiation decisions, but this case requires engineers to select the DTP state that waits for a neighbor to initiate a trunk proposal. DTP dynamic auto matches the evidence more precisely.
2. Correct channel-group protocol pairing would affect matching aggregation protocol behavior, a legitimate protocol compatibility purpose. The stem instead depends on engineers being able to select the DTP state that waits for a neighbor to initiate a trunk proposal. DTP dynamic auto provides that exact behavior, leaving this option operationally wrong.
3. DTP dynamic desirable would be useful when active DTP trunk negotiation is needed for DTP negotiation work. This question instead asks the team to select the DTP state that waits for a neighbor to initiate a trunk proposal. The correct control is DTP dynamic auto, so this alternative fails scenario fit.
4. The required mechanism is DTP dynamic auto, which gives passive DTP trunk negotiation. The stem calls for the team to select the DTP state that waits for a neighbor to initiate a trunk proposal. That makes this the direct DTP negotiation answer rather than an adjacent workaround. This makes DTP dynamic auto the direct fit for this case.

 

Question 6

A campus engineer is preparing a controlled change. The requirement is to harden a static trunk so a neighboring device cannot influence trunk formation with DTP. Which choice most directly satisfies that requirement? Choose ONE.

1. EtherChannel load-balancing method
2. PAgP auto mode
3. switchport nonegotiate
4. DTP dynamic auto

Correct Answer(s)

 

C

Rationale

1. EtherChannel load-balancing method is not selected because it governs a more suitable per-flow distribution key. That function belongs to load balancing work. The required task is to harden a static trunk so a neighboring device cannot influence trunk formation with DTP, and that task is handled by switchport nonegotiate.
2. PAgP auto mode misses the controlling requirement because its result is passive PAgP EtherChannel participation. That fits PAgP negotiation tasks. Here, the network needs engineers to harden a static trunk so a neighboring device cannot influence trunk formation with DTP, so switchport nonegotiate is the relevant mechanism.
3. Switchport nonegotiate provides a trunk that does not send DTP. That matches the requirement to harden a static trunk so a neighboring device cannot influence trunk formation with DTP. It directly controls the relevant DTP suppression behavior, so the alternatives would change a different condition. This makes switchport nonegotiate the direct fit for this case.
4. DTP dynamic auto would be an unnecessary change because it controls passive DTP trunk negotiation. That is relevant to DTP negotiation requirements, while the current task is to harden a static trunk so a neighboring device cannot influence trunk formation with DTP using switchport nonegotiate.

 

Question 7

An enterprise switch change is being peer-reviewed. The design must choose the setting that maps an ordinary endpoint into exactly one intended VLAN. Which option should be approved? Choose ONE.

1. correct access VLAN assignment
2. static EtherChannel on mode
3. STP on the port-channel
4. switchport nonegotiate

Correct Answer(s)

 

A

Rationale

1. The best answer is correct access VLAN assignment, which supplies placement of an endpoint in the intended VLAN. Because the requirement is to choose the setting that maps an ordinary endpoint into exactly one intended VLAN, this option matches the access-port VLAN decision and leaves adjacent functions untouched. This makes correct access VLAN assignment the direct fit for this case.
2. Static EtherChannel on mode solves the wrong problem by producing a protocol-free static EtherChannel. It fits static aggregation needs, but the tested task is to choose the setting that maps an ordinary endpoint into exactly one intended VLAN. That requirement maps directly to correct access VLAN assignment.
3. STP on the port-channel provides spanning-tree control of the logical bundle, which belongs to STP and aggregation decisions. The stem instead requires engineers to choose the setting that maps an ordinary endpoint into exactly one intended VLAN. That result comes from correct access VLAN assignment; selecting STP on the port-channel would leave the tested condition unresolved.
4. Switchport nonegotiate solves a different problem by providing a trunk that does not send DTP. That matters for DTP suppression decisions, but this case requires engineers to choose the setting that maps an ordinary endpoint into exactly one intended VLAN. correct access VLAN assignment matches the evidence more precisely.

 

Question 8

A post-change check found a specific production issue. The engineer now needs to select the LACP state that can successfully pair with a passive partner by initiating negotiation. Which choice best resolves it? Choose ONE.

1. Layer 3 port-channel interface
2. LACP active mode
3. consistent EtherChannel member parameters
4. correct access VLAN assignment

Correct Answer(s)

 

B

Rationale

1. Layer 3 port-channel interface is technically useful for a single routed logical interface over several links in Layer 3 aggregation work. The tested task is to select the LACP state that can successfully pair with a passive partner by initiating negotiation, however. That behavior is governed by LACP active mode, making this option a distractor.
2. LACP active mode matches the desired state by providing active standards-based EtherChannel negotiation. Since engineers must select the LACP state that can successfully pair with a passive partner by initiating negotiation, this selection acts on the relevant LACP negotiation behavior and directly satisfies the requirement. This makes LACP active mode the direct fit for this case.
3. Do not select consistent EtherChannel member parameters; its effect is compatible member-link configuration, a valid bundle consistency function. The scenario requires engineers to select the LACP state that can successfully pair with a passive partner by initiating negotiation. That requirement maps to LACP active mode, not to this alternative.
4. Correct access VLAN assignment misses the controlling requirement because its result is placement of an endpoint in the intended VLAN. That fits access-port VLAN tasks. Here, the network needs engineers to select the LACP state that can successfully pair with a passive partner by initiating negotiation, so LACP active mode is the relevant mechanism.

 

Question 9

An infrastructure engineer is correcting a production condition. The objective is to select the LACP state that is appropriate only because the partner is already configured to initiate. Which option should be implemented? Choose ONE.

1. LACP active mode
2. LACP passive mode
3. restore required VLAN on the trunk
4. port-channel logical interface configuration

Correct Answer(s)

 

B

Rationale

1. LACP active mode solves the wrong problem by producing active standards-based EtherChannel negotiation. It fits LACP negotiation needs, but the tested task is to select the LACP state that is appropriate only because the partner is already configured to initiate. That requirement maps directly to LACP passive mode.
2. Choose LACP passive mode. It creates passive standards-based EtherChannel participation, while the stem requires engineers to select the LACP state that is appropriate only because the partner is already configured to initiate. This directly satisfies the LACP negotiation condition and avoids changing a feature that is not implicated. This makes LACP passive mode the direct fit for this case.
3. Restore required VLAN on the trunk is not an equivalent substitute because it creates targeted restoration of the missing VLAN. That serves trunk VLAN filtering needs, not the requirement to select the LACP state that is appropriate only because the partner is already configured to initiate. LACP passive mode acts on the condition described in the stem.
4. Port-channel logical interface configuration is a neighboring feature that yields consistent aggregate-level configuration for port-channel configuration needs. This scenario requires the team to select the LACP state that is appropriate only because the partner is already configured to initiate. The required behavior belongs to LACP passive mode, so this alternative is mismatched.

 

Question 10

A campus engineer is preparing a controlled change. The requirement is to select the PAgP state that can pair with auto by actively sending negotiation messages. Which choice most directly satisfies that requirement? Choose ONE.

1. show etherchannel summary
2. static 802.1Q trunk mode
3. LACP passive mode
4. PAgP desirable mode

Correct Answer(s)

 

D

Rationale

1. Show etherchannel summary does not resolve the requirement; it provides direct EtherChannel membership verification for EtherChannel verification decisions. Because the stem requires engineers to select the PAgP state that can pair with auto by actively sending negotiation messages, PAgP desirable mode is the mechanism that should be selected.
2. Static 802.1Q trunk mode is related but operationally wrong because it yields an administratively forced trunk. That supports trunk mode work. This case requires engineers to select the PAgP state that can pair with auto by actively sending negotiation messages, so PAgP desirable mode fits the stated condition.
3. Do not select LACP passive mode; its effect is passive standards-based EtherChannel participation, a valid LACP negotiation function. The scenario requires engineers to select the PAgP state that can pair with auto by actively sending negotiation messages. That requirement maps to PAgP desirable mode, not to this alternative.
4. PAgP desirable mode fits because it delivers active PAgP EtherChannel negotiation. The scenario specifically asks engineers to select the PAgP state that can pair with auto by actively sending negotiation messages. This is the PAgP negotiation control that changes the tested behavior directly. This makes PAgP desirable mode the direct fit for this case.

 

Question 11

An enterprise switch change is being peer-reviewed. The design must select the PAgP state that depends on a desirable peer to initiate the exchange. Which option should be approved? Choose ONE.

1. PAgP auto mode
2. correct channel-group protocol pairing
3. matching native VLAN
4. PAgP desirable mode

Correct Answer(s)

 

A

Rationale

1. For this case, PAgP auto mode supplies passive PAgP EtherChannel participation. The operational need is to select the PAgP state that depends on a desirable peer to initiate the exchange. That correspondence makes it the correct PAgP negotiation mechanism for the scenario. This makes PAgP auto mode the direct fit for this case.
2. Correct channel-group protocol pairing fails on scenario fit: it gives matching aggregation protocol behavior for protocol compatibility decisions. The evidence says engineers must select the PAgP state that depends on a desirable peer to initiate the exchange, and PAgP auto mode is the option that provides the needed behavior.
3. Matching native VLAN would change consistent handling of untagged frames, which is appropriate in trunk VLAN consistency scenarios. The present stem asks engineers to select the PAgP state that depends on a desirable peer to initiate the exchange. That is why PAgP auto mode is the correct mechanism instead.
4. PAgP desirable mode is a neighboring feature that yields active PAgP EtherChannel negotiation for PAgP negotiation needs. This scenario requires the team to select the PAgP state that depends on a desirable peer to initiate the exchange. The required behavior belongs to PAgP auto mode, so this alternative is mismatched.

 

Question 12

A post-change check found a specific production issue. The engineer now needs to choose the aggregation mode for a deliberate protocol-free bundle to a legacy peer. Which choice best resolves it? Choose ONE.

1. PAgP auto mode
2. EtherChannel load-balancing method
3. static EtherChannel on mode
4. allowed VLAN list

Correct Answer(s)

 

C

Rationale

1. PAgP auto mode does not resolve the requirement; it provides passive PAgP EtherChannel participation for PAgP negotiation decisions. Because the stem requires engineers to choose the aggregation mode for a deliberate protocol-free bundle to a legacy peer, static EtherChannel on mode is the mechanism that should be selected.
2. EtherChannel load-balancing method targets a more suitable per-flow distribution key, so it fits another load balancing condition. The question requires the team to choose the aggregation mode for a deliberate protocol-free bundle to a legacy peer. Since static EtherChannel on mode produces the needed behavior, this choice would not fix the root requirement.
3. Static EtherChannel on mode is the functional match: it provides a protocol-free static EtherChannel. The question requires the network to choose the aggregation mode for a deliberate protocol-free bundle to a legacy peer. That makes this the relevant static aggregation choice for the stated evidence. This makes static EtherChannel on mode the direct fit for this case.
4. Allowed VLAN list should not be changed for this issue; it provides forwarding of the required VLAN on the trunk for trunk VLAN filtering cases. The actual requirement is to choose the aggregation mode for a deliberate protocol-free bundle to a legacy peer, which is handled by static EtherChannel on mode.

 

Question 13

An infrastructure engineer is correcting a production condition. The objective is to verify the configuration class that must match before a physical trunk can join an existing EtherChannel. Which option should be implemented? Choose ONE.

1. consistent EtherChannel member parameters
2. STP on the port-channel
3. DTP dynamic desirable
4. static EtherChannel on mode

Correct Answer(s)

 

A

Rationale

1. Use consistent EtherChannel member parameters; its operational effect is compatible member-link configuration. The stated task is to verify the configuration class that must match before a physical trunk can join an existing EtherChannel. That mechanism addresses the bundle consistency requirement without altering an unrelated control. This makes consistent EtherChannel member parameters the direct fit for this case.
2. STP on the port-channel has a different role: it supplies spanning-tree control of the logical bundle in STP and aggregation scenarios. The engineer must verify the configuration class that must match before a physical trunk can join an existing EtherChannel here. That makes consistent EtherChannel member parameters the direct answer and this option unsuitable.
3. DTP dynamic desirable would leave the key condition unchanged because it supplies active DTP trunk negotiation. That is useful for DTP negotiation tasks, while this scenario requires the team to verify the configuration class that must match before a physical trunk can join an existing EtherChannel using consistent EtherChannel member parameters.
4. Static EtherChannel on mode fails on scenario fit: it gives a protocol-free static EtherChannel for static aggregation decisions. The evidence says engineers must verify the configuration class that must match before a physical trunk can join an existing EtherChannel, and consistent EtherChannel member parameters is the option that provides the needed behavior.

 

Question 14

A campus engineer is preparing a controlled change. The requirement is to choose where to place a trunk policy that should describe the aggregate rather than one physical member. Which choice most directly satisfies that requirement? Choose ONE.

1. Layer 3 port-channel interface
2. consistent EtherChannel member parameters
3. port-channel logical interface configuration
4. DTP dynamic auto

Correct Answer(s)

 

C

Rationale

1. Layer 3 port-channel interface lacks the needed control effect; it provides a single routed logical interface over several links for Layer 3 aggregation situations. Here the team must choose where to place a trunk policy that should describe the aggregate rather than one physical member, which port-channel logical interface configuration enables directly.
2. Consistent EtherChannel member parameters targets compatible member-link configuration, so it fits another bundle consistency condition. The question requires the team to choose where to place a trunk policy that should describe the aggregate rather than one physical member. Since port-channel logical interface configuration produces the needed behavior, this choice would not fix the root requirement.
3. Port-channel logical interface configuration is the precise choice because it yields consistent aggregate-level configuration. Here, the network must choose where to place a trunk policy that should describe the aggregate rather than one physical member. The feature therefore resolves the tested port-channel configuration condition instead of a different issue. This makes port-channel logical interface configuration the direct fit for this case.
4. DTP dynamic auto controls passive DTP trunk negotiation and is useful for DTP negotiation work. This case requires the team to choose where to place a trunk policy that should describe the aggregate rather than one physical member. Because port-channel logical interface configuration supplies that behavior, this option acts on the wrong requirement.

 

Question 15

An enterprise switch change is being peer-reviewed. The design must select the command whose output most directly shows channel protocol and member-state flags. Which option should be approved? Choose ONE.

1. restore required VLAN on the trunk
2. port-channel logical interface configuration
3. switchport nonegotiate
4. show etherchannel summary

Correct Answer(s)

 

D

Rationale

1. Restore required VLAN on the trunk is plausible because it delivers targeted restoration of the missing VLAN for trunk VLAN filtering cases. Here the team must select the command whose output most directly shows channel protocol and member-state flags. show etherchannel summary directly controls that state, while this option does not.
2. Port-channel logical interface configuration has a different role: it supplies consistent aggregate-level configuration in port-channel configuration scenarios. The engineer must select the command whose output most directly shows channel protocol and member-state flags here. That makes show etherchannel summary the direct answer and this option unsuitable.
3. Switchport nonegotiate does not match the evidence because it provides a trunk that does not send DTP. That is a DTP suppression function, whereas the stem requires engineers to select the command whose output most directly shows channel protocol and member-state flags. show etherchannel summary is the option tied to that task.
4. Use show etherchannel summary to obtain direct EtherChannel membership verification. That is exactly what the team needs when it must select the command whose output most directly shows channel protocol and member-state flags. The EtherChannel verification decision is therefore resolved by this mechanism, not the alternatives. This makes show etherchannel summary the direct fit for this case.

 

Question 16

A post-change check found a specific production issue. The engineer now needs to choose the remediation that makes both sides of one channel use an interoperable aggregation protocol. Which choice best resolves it? Choose ONE.

802. static 802.1Q trunk mode
803. correct channel-group protocol pairing
804. correct access VLAN assignment
805. show etherchannel summary

Correct Answer(s)

 

B

Rationale

802. Static 802.1Q trunk mode would affect an administratively forced trunk, a legitimate trunk mode purpose. The stem instead depends on engineers being able to choose the remediation that makes both sides of one channel use an interoperable aggregation protocol. correct channel-group protocol pairing provides that exact behavior, leaving this option operationally wrong.
803. Correct channel-group protocol pairing is correct because it creates matching aggregation protocol behavior. In this scenario, engineers must choose the remediation that makes both sides of one channel use an interoperable aggregation protocol. The option acts on the exact protocol compatibility decision described in the stem. This makes correct channel-group protocol pairing the direct fit for this case.
804. Correct access VLAN assignment would be useful when placement of an endpoint in the intended VLAN is needed for access-port VLAN work. This question instead asks the team to choose the remediation that makes both sides of one channel use an interoperable aggregation protocol. The correct control is correct channel-group protocol pairing, so this alternative fails scenario fit.
805. Show etherchannel summary lacks the needed control effect; it provides direct EtherChannel membership verification for EtherChannel verification situations. Here the team must choose the remediation that makes both sides of one channel use an interoperable aggregation protocol, which correct channel-group protocol pairing enables directly.

 

Question 17

An infrastructure engineer is correcting a production condition. The objective is to select the mechanism that changes which packet-header fields choose an EtherChannel member link. Which option should be implemented? Choose ONE.

1. LACP active mode
2. correct channel-group protocol pairing
3. EtherChannel load-balancing method
4. matching native VLAN

Correct Answer(s)

 

C

Rationale

1. LACP active mode would be an unnecessary change because it controls active standards-based EtherChannel negotiation. That is relevant to LACP negotiation requirements, while the current task is to select the mechanism that changes which packet-header fields choose an EtherChannel member link using EtherChannel load-balancing method.
2. Correct channel-group protocol pairing is plausible because it delivers matching aggregation protocol behavior for protocol compatibility cases. Here the team must select the mechanism that changes which packet-header fields choose an EtherChannel member link. EtherChannel load-balancing method directly controls that state, while this option does not.
3. Select EtherChannel load-balancing method for a more suitable per-flow distribution key. The stem makes the requirement explicit: select the mechanism that changes which packet-header fields choose an EtherChannel member link. That result is governed by this load balancing mechanism rather than by the neighboring options. This makes EtherChannel load-balancing method the direct fit for this case.
4. Matching native VLAN is not selected because it governs consistent handling of untagged frames. That function belongs to trunk VLAN consistency work. The required task is to select the mechanism that changes which packet-header fields choose an EtherChannel member link, and that task is handled by EtherChannel load-balancing method.

 

Question 18

A campus engineer is preparing a controlled change. The requirement is to choose the logical interface on which spanning-tree policy should represent an established Layer 2 bundle. Which choice most directly satisfies that requirement? Choose ONE.

1. allowed VLAN list
2. STP on the port-channel
3. EtherChannel load-balancing method
4. LACP passive mode

Correct Answer(s)

 

B

Rationale

1. Allowed VLAN list provides forwarding of the required VLAN on the trunk, which belongs to trunk VLAN filtering decisions. The stem instead requires engineers to choose the logical interface on which spanning-tree policy should represent an established Layer 2 bundle. That result comes from STP on the port-channel; selecting allowed VLAN list would leave the tested condition unresolved.
2. STP on the port-channel is appropriate because the result is spanning-tree control of the logical bundle. The scenario requires engineers to choose the logical interface on which spanning-tree policy should represent an established Layer 2 bundle. This feature controls that STP and aggregation behavior specifically, so it is the best fit. This makes STP on the port-channel the direct fit for this case.
3. EtherChannel load-balancing method would affect a more suitable per-flow distribution key, a legitimate load balancing purpose. The stem instead depends on engineers being able to choose the logical interface on which spanning-tree policy should represent an established Layer 2 bundle. STP on the port-channel provides that exact behavior, leaving this option operationally wrong.
4. LACP passive mode solves a different problem by providing passive standards-based EtherChannel participation. That matters for LACP negotiation decisions, but this case requires engineers to choose the logical interface on which spanning-tree policy should represent an established Layer 2 bundle. STP on the port-channel matches the evidence more precisely.

 

Question 19

An enterprise switch change is being peer-reviewed. The design must select the architecture that presents one routed interface while several physical links provide capacity. Which option should be approved? Choose ONE.

1. Layer 3 port-channel interface
2. PAgP desirable mode
3. DTP dynamic desirable
4. STP on the port-channel

Correct Answer(s)

 

A

Rationale

1. Choose Layer 3 port-channel interface because its result is a single routed logical interface over several links. The stem requires the team to select the architecture that presents one routed interface while several physical links provide capacity. That is a direct Layer 3 aggregation match, not merely a related feature. This makes Layer 3 port-channel interface the direct fit for this case.
2. PAgP desirable mode misses the controlling requirement because its result is active PAgP EtherChannel negotiation. That fits PAgP negotiation tasks. Here, the network needs engineers to select the architecture that presents one routed interface while several physical links provide capacity, so Layer 3 port-channel interface is the relevant mechanism.
3. DTP dynamic desirable is technically useful for active DTP trunk negotiation in DTP negotiation work. The tested task is to select the architecture that presents one routed interface while several physical links provide capacity, however. That behavior is governed by Layer 3 port-channel interface, making this option a distractor.
4. STP on the port-channel is not selected because it governs spanning-tree control of the logical bundle. That function belongs to STP and aggregation work. The required task is to select the architecture that presents one routed interface while several physical links provide capacity, and that task is handled by Layer 3 port-channel interface.

 

Question 20

A post-change check found a specific production issue. The engineer now needs to choose the least disruptive change when the only fault is a required VLAN missing from the trunk allow list. Which choice best resolves it? Choose ONE.

1. DTP dynamic auto
2. Layer 3 port-channel interface
3. PAgP auto mode
4. restore required VLAN on the trunk

Correct Answer(s)

 

D

Rationale

1. DTP dynamic auto is not an equivalent substitute because it creates passive DTP trunk negotiation. That serves DTP negotiation needs, not the requirement to choose the least disruptive change when the only fault is a required VLAN missing from the trunk allow list. restore required VLAN on the trunk acts on the condition described in the stem.
2. Layer 3 port-channel interface provides a single routed logical interface over several links, which belongs to Layer 3 aggregation decisions. The stem instead requires engineers to choose the least disruptive change when the only fault is a required VLAN missing from the trunk allow list. That result comes from restore required VLAN on the trunk; selecting Layer 3 port-channel interface would leave the tested condition unresolved.
3. PAgP auto mode solves the wrong problem by producing passive PAgP EtherChannel participation. It fits PAgP negotiation needs, but the tested task is to choose the least disruptive change when the only fault is a required VLAN missing from the trunk allow list. That requirement maps directly to restore required VLAN on the trunk.
4. Restore required VLAN on the trunk directly produces targeted restoration of the missing VLAN. That is relevant because the team needs to choose the least disruptive change when the only fault is a required VLAN missing from the trunk allow list. For this trunk VLAN filtering decision, the feature changes the condition identified by the evidence. This makes restore required VLAN on the trunk the direct fit for this case.

• < Cisco CCNP 350-401 ENCOR 802.1Q Trunking and EtherChannel Troubleshooting Practice Test 2
• Cisco CCNP 350-401 ENCOR RSTP, MST, Root Guard, and BPDU Guard Practice Test 1 >