HP HPE7-A01 Practice Test 20
Question 190
A building network suffers topology changes after a newly added switch wins root election in the wrong MST instance. The review requires TWO complementary actions: one diagnostic check and one controlled configuration remedy. Select TWO actions that together meet those requirements.
- Review the access port's BPDU guard event, edge designation and the connected device's actual role.
- Review spanning-tree root bridge IDs, priorities, path costs and instance membership.
- Enforce appropriate loop or unidirectional-link protection on susceptible network-facing ports instead of treating them as user edges.
- Set up supported bridge priorities to place the intended core or distribution bridge as STP root for the affected instance.
Explanation
Correct Answers
B:Review spanning-tree root bridge IDs, priorities, path costs and instance membership. STP root placement is an explicit topology control; changing bridge priority can redirect paths even when all links remain physically up. This is the required diagnosis or controlled remedy; the other keyed action supplies the complementary role. The decision applies to the described spanning tree root and loop prevention situation.
D:Set up supported bridge priorities to place the intended core or distribution bridge as STP root for the affected instance. STP root placement is an explicit topology control; changing bridge priority can redirect paths even when all links remain physically up. This is the required diagnosis or controlled remedy; the other keyed action supplies the complementary role. The decision applies to the described spanning tree root and loop prevention situation.
Incorrect Answers
A:Review the access port's BPDU guard event, edge designation and the connected device's actual role. This instead concerns bpdu guard on edge ports. BPDU guard protects edge ports from unintended switching devices; globally disabling it to recover one port increases loop risk. It is not one of the requested paired diagnosis and configuration actions. The immediate problem concerns spanning tree root and loop prevention.
C:Enforce appropriate loop or unidirectional-link protection on susceptible network-facing ports instead of treating them as user edges. This instead concerns loop guard during bpdu loss. Loop guard addresses missed BPDUs on appropriate nonedge links so a broken control plane does not trigger unsafe forwarding. It is not one of the requested paired diagnosis and configuration actions. The immediate problem concerns spanning tree root and loop prevention.
Question 191
A building network suffers topology changes after a newly added switch wins root election in the wrong MST instance. A deployment job reports success. Which observed result would actually validate the affected service?
- Confirm stable root identity, forwarding and blocking states and lower topology-change event counts.
- Validate the edge port rejects the unexpected bridge while authorized end devices reconnect normally for the affected campus deployment.
- Confirm the faulted path remains safely blocked and converges correctly when valid BPDUs return.
- Confirm the correct VLAN and ingress port appear in MAC tables while frames reach the actual device.
Explanation
Correct Answer
A:Confirm stable root identity, forwarding and blocking states and lower topology-change event counts. STP root placement is an explicit topology control; changing bridge priority can redirect paths even when all links remain physically up. The result tests actual working behavior, not merely a saved configuration. The decision applies to the described spanning tree root and loop prevention situation.
Incorrect Answers
B:Validate the edge port rejects the unexpected bridge while authorized end devices reconnect normally for the affected campus deployment. This instead concerns bpdu guard on edge ports. BPDU guard protects edge ports from unintended switching devices; globally disabling it to recover one port increases loop risk. It would not establish that this function actually works. The immediate problem concerns spanning tree root and loop prevention.
C:Confirm the faulted path remains safely blocked and converges correctly when valid BPDUs return. This instead concerns loop guard during bpdu loss. Loop guard addresses missed BPDUs on appropriate nonedge links so a broken control plane does not trigger unsafe forwarding. It would not establish that this function actually works. The immediate problem concerns spanning tree root and loop prevention.
D:Confirm the correct VLAN and ingress port appear in MAC tables while frames reach the actual device. This instead concerns mac address learning and movement. Ethernet switches forward based on per-VLAN learned MAC locations; stale or rapidly moving entries can misdirect otherwise valid frames. It would not establish that this function actually works. The immediate problem concerns spanning tree root and loop prevention.
Question 192
A building network suffers topology changes after a newly added switch wins root election in the wrong MST instance. If the revised setting disrupts users, which controlled rollback would be most relevant?
- Eliminate the unauthorized bridge and clear the guard-triggered port fault only after verifying proper edge policy.
- Reinstate the last safe STP protection settings and isolate the suspect optical path until the one-way fault is removed.
- Reinstate the former forwarding path and clear only affected stale dynamic entries if controlled remediation requires it.
- Reinstate the approved bridge priorities and remove the misconfigured link if an unintended loop appears.
Explanation
Correct Answer
D:Reinstate the approved bridge priorities and remove the misconfigured link if an unintended loop appears. STP root placement is an explicit topology control; changing bridge priority can redirect paths even when all links remain physically up. The focused rollback restores a known safe baseline before another change attempt. The decision applies to the described spanning tree root and loop prevention situation.
Incorrect Answers
A:Eliminate the unauthorized bridge and clear the guard-triggered port fault only after verifying proper edge policy. This instead concerns bpdu guard on edge ports. BPDU guard protects edge ports from unintended switching devices; globally disabling it to recover one port increases loop risk. It would not safely roll back the relevant failed change. The immediate problem concerns spanning tree root and loop prevention.
B:Reinstate the last safe STP protection settings and isolate the suspect optical path until the one-way fault is removed. This instead concerns loop guard during bpdu loss. Loop guard addresses missed BPDUs on appropriate nonedge links so a broken control plane does not trigger unsafe forwarding. It would not safely roll back the relevant failed change. The immediate problem concerns spanning tree root and loop prevention.
C:Reinstate the former forwarding path and clear only affected stale dynamic entries if controlled remediation requires it. This instead concerns mac address learning and movement. Ethernet switches forward based on per-VLAN learned MAC locations; stale or rapidly moving entries can misdirect otherwise valid frames. It would not safely roll back the relevant failed change. The immediate problem concerns spanning tree root and loop prevention.
Question 193
A user plugs a small switch into a protected desk port, causing the interface to disable after receiving a BPDU. Which investigation would best isolate the immediate network dependency?
- Inspect STP role, loss of BPDUs and any loop-inconsistent or unidirectional-link events.
- Inspect dynamic MAC table age, VLAN context, MAC moves and source-port learning on the affected switches.
- Inspect secure MAC learning, violation counters and the required number of authorized devices on the port.
- Inspect the access port's BPDU guard event, edge designation and the connected device's actual role.
Explanation
Correct Answer
D:Inspect the access port's BPDU guard event, edge designation and the connected device's actual role. BPDU guard protects edge ports from unintended switching devices; globally disabling it to recover one port increases loop risk. The evidence check isolates the relevant prerequisite before a disruptive change. The decision applies to the described bpdu guard on edge ports situation.
Incorrect Answers
A:Inspect STP role, loss of BPDUs and any loop-inconsistent or unidirectional-link events. This instead concerns loop guard during bpdu loss. Loop guard addresses missed BPDUs on appropriate nonedge links so a broken control plane does not trigger unsafe forwarding. It does not isolate the cause of the stated incident. The immediate problem concerns bpdu guard on edge ports.
B:Inspect dynamic MAC table age, VLAN context, MAC moves and source-port learning on the affected switches. This instead concerns mac address learning and movement. Ethernet switches forward based on per-VLAN learned MAC locations; stale or rapidly moving entries can misdirect otherwise valid frames. It does not isolate the cause of the stated incident. The immediate problem concerns bpdu guard on edge ports.
C:Inspect secure MAC learning, violation counters and the required number of authorized devices on the port. This instead concerns port-security mac limits. A MAC limit must reflect legitimate devices and threat policy; increasing it blindly can conceal an unauthorized downstream bridge. It does not isolate the cause of the stated incident. The immediate problem concerns bpdu guard on edge ports.
Question 194
A user plugs a small switch into a protected desk port, causing the interface to disable after receiving a BPDU. Which specific corrective design step best meets the stated campus requirement?
- Apply appropriate loop or unidirectional-link protection on susceptible network-facing ports instead of treating them as user edges.
- Correct the unwanted Layer 2 forwarding path or mobility condition and let normal address learning converge.
- Retain edge BPDU guard for user-facing ports and move legitimate infrastructure bridges to appropriately managed uplinks.
- Set a justified port-security limit or approved access policy for the actual endpoint composition without permitting unbounded clients.
Explanation
Correct Answer
C:Retain edge BPDU guard for user-facing ports and move legitimate infrastructure bridges to appropriately managed uplinks. BPDU guard protects edge ports from unintended switching devices; globally disabling it to recover one port increases loop risk. The proposed configuration targets the stated dependency without broadening unrelated access. The decision applies to the described bpdu guard on edge ports situation.
Incorrect Answers
A:Apply appropriate loop or unidirectional-link protection on susceptible network-facing ports instead of treating them as user edges. This instead concerns loop guard during bpdu loss. Loop guard addresses missed BPDUs on appropriate nonedge links so a broken control plane does not trigger unsafe forwarding. It would not implement the specifically required change. The immediate problem concerns bpdu guard on edge ports.
B:Correct the unwanted Layer 2 forwarding path or mobility condition and let normal address learning converge. This instead concerns mac address learning and movement. Ethernet switches forward based on per-VLAN learned MAC locations; stale or rapidly moving entries can misdirect otherwise valid frames. It would not implement the specifically required change. The immediate problem concerns bpdu guard on edge ports.
D:Set a justified port-security limit or approved access policy for the actual endpoint composition without permitting unbounded clients. This instead concerns port-security mac limits. A MAC limit must reflect legitimate devices and threat policy; increasing it blindly can conceal an unauthorized downstream bridge. It would not implement the specifically required change. The immediate problem concerns bpdu guard on edge ports.
Question 195
A user plugs a small switch into a protected desk port, causing the interface to disable after receiving a BPDU. Following a targeted change, which acceptance test would most directly demonstrate success?
- Verify the faulted path remains safely blocked and converges correctly when valid BPDUs return.
- Validate the edge port rejects the unexpected bridge while authorized end devices reconnect normally.
- Verify the correct VLAN and ingress port appear in MAC tables while frames reach the actual device.
- Verify both intended endpoints learn securely and an additional unauthorized MAC still produces the designed violation.
Explanation
Correct Answer
B:Validate the edge port rejects the unexpected bridge while authorized end devices reconnect normally. BPDU guard protects edge ports from unintended switching devices; globally disabling it to recover one port increases loop risk. The result tests actual working behavior, not merely a saved configuration. The decision applies to the described bpdu guard on edge ports situation.
Incorrect Answers
A:Verify the faulted path remains safely blocked and converges correctly when valid BPDUs return. This instead concerns loop guard during bpdu loss. Loop guard addresses missed BPDUs on appropriate nonedge links so a broken control plane does not trigger unsafe forwarding. It would not establish that this function actually works. The immediate problem concerns bpdu guard on edge ports.
C:Verify the correct VLAN and ingress port appear in MAC tables while frames reach the actual device. This instead concerns mac address learning and movement. Ethernet switches forward based on per-VLAN learned MAC locations; stale or rapidly moving entries can misdirect otherwise valid frames. It would not establish that this function actually works. The immediate problem concerns bpdu guard on edge ports.
D:Verify both intended endpoints learn securely and an additional unauthorized MAC still produces the designed violation. This instead concerns port-security mac limits. A MAC limit must reflect legitimate devices and threat policy; increasing it blindly can conceal an unauthorized downstream bridge. It would not establish that this function actually works. The immediate problem concerns bpdu guard on edge ports.
Question 196
A user plugs a small switch into a protected desk port, causing the interface to disable after receiving a BPDU. The change fails acceptance. What is the safest targeted restoration action?
- Remove the unauthorized bridge and clear the guard-triggered port fault only after verifying proper edge policy.
- Restore the last safe STP protection settings and isolate the suspect optical path until the one-way fault is removed.
- Restore the former forwarding path and clear only affected stale dynamic entries if controlled remediation requires it.
- Restore the prior secure profile and connect only the authorized endpoint while reviewing any needed exception.
Explanation
Correct Answer
A:Remove the unauthorized bridge and clear the guard-triggered port fault only after verifying proper edge policy. BPDU guard protects edge ports from unintended switching devices; globally disabling it to recover one port increases loop risk. The focused rollback restores a known safe baseline before another change attempt. The decision applies to the described bpdu guard on edge ports situation.
Incorrect Answers
B:Restore the last safe STP protection settings and isolate the suspect optical path until the one-way fault is removed. This instead concerns loop guard during bpdu loss. Loop guard addresses missed BPDUs on appropriate nonedge links so a broken control plane does not trigger unsafe forwarding. It would not safely roll back the relevant failed change. The immediate problem concerns bpdu guard on edge ports.
C:Restore the former forwarding path and clear only affected stale dynamic entries if controlled remediation requires it. This instead concerns mac address learning and movement. Ethernet switches forward based on per-VLAN learned MAC locations; stale or rapidly moving entries can misdirect otherwise valid frames. It would not safely roll back the relevant failed change. The immediate problem concerns bpdu guard on edge ports.
D:Restore the prior secure profile and connect only the authorized endpoint while reviewing any needed exception. This instead concerns port-security mac limits. A MAC limit must reflect legitimate devices and threat policy; increasing it blindly can conceal an unauthorized downstream bridge. It would not safely roll back the relevant failed change. The immediate problem concerns bpdu guard on edge ports.
Question 197
A room's access port unexpectedly shuts when a contractor attaches a bridge that advertises spanning-tree control frames. The review requires TWO complementary actions: one diagnostic check and one controlled configuration remedy. Select TWO actions that together meet those requirements.
- Review STP role, loss of BPDUs and any loop-inconsistent or unidirectional-link events.
- Review the access port's BPDU guard event, edge designation and the connected device's actual role.
- Repair the unwanted Layer 2 forwarding path or mobility condition and let normal address learning converge.
- Keep edge BPDU guard for user-facing ports and move legitimate infrastructure bridges to appropriately managed uplinks.
Explanation
Correct Answers
B:Review the access port's BPDU guard event, edge designation and the connected device's actual role. BPDU guard protects edge ports from unintended switching devices; globally disabling it to recover one port increases loop risk. This is the required diagnosis or controlled remedy; the other keyed action supplies the complementary role. The decision applies to the described bpdu guard on edge ports situation.
D:Keep edge BPDU guard for user-facing ports and move legitimate infrastructure bridges to appropriately managed uplinks. BPDU guard protects edge ports from unintended switching devices; globally disabling it to recover one port increases loop risk. This is the required diagnosis or controlled remedy; the other keyed action supplies the complementary role. The decision applies to the described bpdu guard on edge ports situation.
Incorrect Answers
A:Review STP role, loss of BPDUs and any loop-inconsistent or unidirectional-link events. This instead concerns loop guard during bpdu loss. Loop guard addresses missed BPDUs on appropriate nonedge links so a broken control plane does not trigger unsafe forwarding. It is not one of the requested paired diagnosis and configuration actions. The immediate problem concerns bpdu guard on edge ports.
C:Repair the unwanted Layer 2 forwarding path or mobility condition and let normal address learning converge. This instead concerns mac address learning and movement. Ethernet switches forward based on per-VLAN learned MAC locations; stale or rapidly moving entries can misdirect otherwise valid frames. It is not one of the requested paired diagnosis and configuration actions. The immediate problem concerns bpdu guard on edge ports.
Question 198
A room's access port unexpectedly shuts when a contractor attaches a bridge that advertises spanning-tree control frames. After the root cause is confirmed, which narrowly scoped configuration action should be selected?
- Enforce appropriate loop or unidirectional-link protection on susceptible network-facing ports instead of treating them as user edges.
- Repair the unwanted Layer 2 forwarding path or mobility condition and let normal address learning converge.
- Keep edge BPDU guard for user-facing ports and move legitimate infrastructure bridges to appropriately managed uplinks.
- Apply a justified port-security limit or approved access policy for the actual endpoint composition without permitting unbounded clients.
Explanation
Correct Answer
C:Keep edge BPDU guard for user-facing ports and move legitimate infrastructure bridges to appropriately managed uplinks. BPDU guard protects edge ports from unintended switching devices; globally disabling it to recover one port increases loop risk. The proposed configuration targets the stated dependency without broadening unrelated access. The decision applies to the described bpdu guard on edge ports situation.
Incorrect Answers
A:Enforce appropriate loop or unidirectional-link protection on susceptible network-facing ports instead of treating them as user edges. This instead concerns loop guard during bpdu loss. Loop guard addresses missed BPDUs on appropriate nonedge links so a broken control plane does not trigger unsafe forwarding. It would not implement the specifically required change. The immediate problem concerns bpdu guard on edge ports.
B:Repair the unwanted Layer 2 forwarding path or mobility condition and let normal address learning converge. This instead concerns mac address learning and movement. Ethernet switches forward based on per-VLAN learned MAC locations; stale or rapidly moving entries can misdirect otherwise valid frames. It would not implement the specifically required change. The immediate problem concerns bpdu guard on edge ports.
D:Apply a justified port-security limit or approved access policy for the actual endpoint composition without permitting unbounded clients. This instead concerns port-security mac limits. A MAC limit must reflect legitimate devices and threat policy; increasing it blindly can conceal an unauthorized downstream bridge. It would not implement the specifically required change. The immediate problem concerns bpdu guard on edge ports.
Question 199
A room's access port unexpectedly shuts when a contractor attaches a bridge that advertises spanning-tree control frames. A deployment job reports success. Which observed result would actually validate the affected service?
- Confirm the faulted path remains safely blocked and converges correctly when valid BPDUs return.
- Validate the edge port rejects the unexpected bridge while authorized end devices reconnect normally for the affected campus deployment.
- Confirm the correct VLAN and ingress port appear in MAC tables while frames reach the actual device.
- Confirm both intended endpoints learn securely and an additional unauthorized MAC still produces the designed violation.
Explanation
Correct Answer
B:Validate the edge port rejects the unexpected bridge while authorized end devices reconnect normally for the affected campus deployment. BPDU guard protects edge ports from unintended switching devices; globally disabling it to recover one port increases loop risk. The result tests actual working behavior, not merely a saved configuration. The decision applies to the described bpdu guard on edge ports situation.
Incorrect Answers
A:Confirm the faulted path remains safely blocked and converges correctly when valid BPDUs return. This instead concerns loop guard during bpdu loss. Loop guard addresses missed BPDUs on appropriate nonedge links so a broken control plane does not trigger unsafe forwarding. It would not establish that this function actually works. The immediate problem concerns bpdu guard on edge ports.
C:Confirm the correct VLAN and ingress port appear in MAC tables while frames reach the actual device. This instead concerns mac address learning and movement. Ethernet switches forward based on per-VLAN learned MAC locations; stale or rapidly moving entries can misdirect otherwise valid frames. It would not establish that this function actually works. The immediate problem concerns bpdu guard on edge ports.
D:Confirm both intended endpoints learn securely and an additional unauthorized MAC still produces the designed violation. This instead concerns port-security mac limits. A MAC limit must reflect legitimate devices and threat policy; increasing it blindly can conceal an unauthorized downstream bridge. It would not establish that this function actually works. The immediate problem concerns bpdu guard on edge ports.
Question 200
A room's access port unexpectedly shuts when a contractor attaches a bridge that advertises spanning-tree control frames. If the revised setting disrupts users, which controlled rollback would be most relevant?
- Eliminate the unauthorized bridge and clear the guard-triggered port fault only after verifying proper edge policy.
- Reinstate the last safe STP protection settings and isolate the suspect optical path until the one-way fault is removed.
- Reinstate the former forwarding path and clear only affected stale dynamic entries if controlled remediation requires it.
- Reinstate the prior secure profile and connect only the authorized endpoint while reviewing any needed exception.
Explanation
Correct Answer
A:Eliminate the unauthorized bridge and clear the guard-triggered port fault only after verifying proper edge policy. BPDU guard protects edge ports from unintended switching devices; globally disabling it to recover one port increases loop risk. The focused rollback restores a known safe baseline before another change attempt. The decision applies to the described bpdu guard on edge ports situation.
Incorrect Answers
B:Reinstate the last safe STP protection settings and isolate the suspect optical path until the one-way fault is removed. This instead concerns loop guard during bpdu loss. Loop guard addresses missed BPDUs on appropriate nonedge links so a broken control plane does not trigger unsafe forwarding. It would not safely roll back the relevant failed change. The immediate problem concerns bpdu guard on edge ports.
C:Reinstate the former forwarding path and clear only affected stale dynamic entries if controlled remediation requires it. This instead concerns mac address learning and movement. Ethernet switches forward based on per-VLAN learned MAC locations; stale or rapidly moving entries can misdirect otherwise valid frames. It would not safely roll back the relevant failed change. The immediate problem concerns bpdu guard on edge ports.
D:Reinstate the prior secure profile and connect only the authorized endpoint while reviewing any needed exception. This instead concerns port-security mac limits. A MAC limit must reflect legitimate devices and threat policy; increasing it blindly can conceal an unauthorized downstream bridge. It would not safely roll back the relevant failed change. The immediate problem concerns bpdu guard on edge ports.
