Cisco Certified Support Technician (CCST) Networking 100-150 Practice Test 72
Question 710
Before changing settings, consider this issue: At the fictional Stonewater Manufacturing before a planned system change, the team observes: A help desk attributes a recurring outage to 'user error' without collecting interface counters, logs or endpoint details. What is the MOST specific underlying cause?
- Root-cause conclusions require supporting observations and elimination of plausible alternatives.
- Broad capture duration and scope can violate least-collection and data-privacy requirements.
- A packet analyzer must capture on the interface carrying the traffic under investigation.
- show interfaces status provides a concise status and often VLAN and speed summary on supported switch models.
Explanation
Correct Answer
A:Correct. This mechanism fits the observed network symptom at the fictional Stonewater Manufacturing: Root-cause conclusions require supporting observations and elimination of plausible alternatives. The corresponding remedy is “Gather relevant logs, port status and endpoint tests before writing a diagnosis.”. Confirmation: The incident's cause statement is supported by reproducible technical evidence.
Incorrect Answers
B:That cause belongs to a different case: An engineer captures on a production uplink for hours without approval and collects traffic from unrelated departments to debug one laptop. The observed fictional Stonewater Manufacturing condition is specifically explained by “Root-cause conclusions require supporting observations and elimination of plausible alternatives.”.
C:That cause belongs to a different case: A technician captures packets on a laptop's inactive Ethernet adapter and sees nothing while the issue occurs over active Wi-Fi. The observed fictional Stonewater Manufacturing condition is specifically explained by “Root-cause conclusions require supporting observations and elimination of plausible alternatives.”.
D:That cause belongs to a different case: A technician needs a quick view of which switch ports are connected or disconnected but the engineer dumps a full device configuration and misses the status overview. The observed fictional Stonewater Manufacturing condition is specifically explained by “Root-cause conclusions require supporting observations and elimination of plausible alternatives.”.
Question 711
A reviewer evaluates a proposed repair for: At the fictional Stonewater Manufacturing before a planned system change, the team observes: A help desk attributes a recurring outage to 'user error' without collecting interface counters, logs or endpoint details. The approved corrective action is: “Gather relevant logs, port status and endpoint tests before writing a diagnosis.” Which result BEST demonstrates success?
- The management session negotiates SSH and the plaintext Telnet service is not required.
- The monitoring dashboard identifies the affected devices and retains consistent timestamps.
- The capture review identifies loss/retry behavior without mislabeling it as authentication denial.
- The incident's cause statement is supported by reproducible technical evidence.
Explanation
Correct Answer
D:Correct. This is the required observable acceptance evidence for “Gather relevant logs, port status and endpoint tests before writing a diagnosis.” at the fictional Stonewater Manufacturing. It demonstrates correction of the original cause: Root-cause conclusions require supporting observations and elimination of plausible alternatives.
Incorrect Answers
A:That result is evidence for a separate corrective action, “Use SSH with authenticated device identity and approved credentials for remote CLI access.”. It does not establish the intended outcome “The incident's cause statement is supported by reproducible technical evidence.” for the fictional Stonewater Manufacturing case.
B:That result is evidence for a separate corrective action, “Query the approved NMS and compare its alert scope with device-specific interface evidence.”. It does not establish the intended outcome “The incident's cause statement is supported by reproducible technical evidence.” for the fictional Stonewater Manufacturing case.
C:That result is evidence for a separate corrective action, “Compare TCP sequence, acknowledgment and retransmission evidence separately from application-layer status.”. It does not establish the intended outcome “The incident's cause statement is supported by reproducible technical evidence.” for the fictional Stonewater Manufacturing case.
Question 712
The technician plans a correction for: At the fictional Stonewater Manufacturing before a planned system change, the team observes: A help desk attributes a recurring outage to 'user error' without collecting interface counters, logs or endpoint details. During “Gather relevant logs, port status and endpoint tests before writing a diagnosis.”, which precaution MOST specifically prevents a related risk?
- Do not treat hardware inventory output as evidence of IP forwarding decisions.
- Do not assume a hostname uniquely determines which NIC transmits a given flow.
- Do not accuse a user or device without recorded data supporting the conclusion.
- Do not repair browser history in place of missing IP routing configuration.
Explanation
Correct Answer
C:Correct. This precaution prevents a second fault while applying “Gather relevant logs, port status and endpoint tests before writing a diagnosis.” at the fictional Stonewater Manufacturing. The required protection is “Do not accuse a user or device without recorded data supporting the conclusion.”; success still requires “The incident's cause statement is supported by reproducible technical evidence.”.
Incorrect Answers
A:This caution is appropriate for a separate failure pattern: A technician wants to know the route selected for 10.40.0.0/16 but reads only show inventory and calls that a routing lookup. The principal adjacent risk here is controlled by “Do not accuse a user or device without recorded data supporting the conclusion.”.
B:This caution is appropriate for a separate failure pattern: A Linux host shows two IPv4 addresses on different NICs but a troubleshooter reads only its hostname to determine which address a route uses. The principal adjacent risk here is controlled by “Do not accuse a user or device without recorded data supporting the conclusion.”.
D:This caution is appropriate for a separate failure pattern: A Windows client has no IPv4 default gateway and a technician checks only browser cache before escalating a routing outage. The principal adjacent risk here is controlled by “Do not accuse a user or device without recorded data supporting the conclusion.”.
Question 713
A service desk receives this network finding: At the fictional Sunrise Payment Office in a technician onboarding review, the team observes: A site network outage is repaired, but follow-up documentation omits what changed and which devices were touched. Which action MOST directly resolves the reported issue?
- Save the relevant capture in an approved .pcap or .pcapng file with case identification.
- Record the baseline, intervention, validation and follow-up actions in the ticket and change log.
- Inspect TLS handshake metadata and transport behavior rather than promising automatic plaintext disclosure.
- Attach an approved console adapter and inspect the device's configuration through the terminal emulator.
Explanation
Correct Answer
B:Correct. In the fictional Sunrise Payment Office case, Complete operational records support repeatability, auditing and preventing recurrence. The specified corrective action, “Record the baseline, intervention, validation and follow-up actions in the ticket and change log.”, directly targets that condition. Evidence of resolution: The closing record permits another technician to reconstruct and verify the repair.
Incorrect Answers
A:That action addresses a different network issue: An operator captures a DNS exchange in Wireshark but closes the capture without saving any file for escalation. The present fictional Sunrise Payment Office finding instead needs “Record the baseline, intervention, validation and follow-up actions in the ticket and change log.”, verified by “The closing record permits another technician to reconstruct and verify the repair.”.
C:That action addresses a different network issue: A user says a packet analyzer can reconstruct any encrypted HTTPS password from normal packet capture without keys. The present fictional Sunrise Payment Office finding instead needs “Record the baseline, intervention, validation and follow-up actions in the ticket and change log.”, verified by “The closing record permits another technician to reconstruct and verify the repair.”.
D:That action addresses a different network issue: A switch's management IP is misconfigured and remote SSH fails, but an on-site technician refuses to use its working console port. The present fictional Sunrise Payment Office finding instead needs “Record the baseline, intervention, validation and follow-up actions in the ticket and change log.”, verified by “The closing record permits another technician to reconstruct and verify the repair.”.
Question 714
Before changing settings, consider this issue: At the fictional Sunrise Payment Office in a technician onboarding review, the team observes: A site network outage is repaired, but follow-up documentation omits what changed and which devices were touched. What is the MOST specific underlying cause?
- Complete operational records support repeatability, auditing and preventing recurrence.
- Cloud-managed network devices may be monitored and configured through their assigned management platform.
- A packet analyzer must capture on the interface carrying the traffic under investigation.
- Incorrect or stale DNS answers can direct an application to a wrong destination independently of local subnetting.
Explanation
Correct Answer
A:Correct. This mechanism fits the observed network symptom at the fictional Sunrise Payment Office: Complete operational records support repeatability, auditing and preventing recurrence. The corresponding remedy is “Record the baseline, intervention, validation and follow-up actions in the ticket and change log.”. Confirmation: The closing record permits another technician to reconstruct and verify the repair.
Incorrect Answers
B:That cause belongs to a different case: A managed Meraki access point shows a cloud-dashboard alert but the trainee tries to repair it through an unrelated legacy local switch GUI. The observed fictional Sunrise Payment Office condition is specifically explained by “Complete operational records support repeatability, auditing and preventing recurrence.”.
C:That cause belongs to a different case: A technician captures packets on a laptop's inactive Ethernet adapter and sees nothing while the issue occurs over active Wi-Fi. The observed fictional Sunrise Payment Office condition is specifically explained by “Complete operational records support repeatability, auditing and preventing recurrence.”.
D:That cause belongs to a different case: A workstation's name lookup returns an obsolete IP address and the technician changes its subnet mask instead of checking DNS. The observed fictional Sunrise Payment Office condition is specifically explained by “Complete operational records support repeatability, auditing and preventing recurrence.”.
Question 715
A reviewer evaluates a proposed repair for: At the fictional Sunrise Payment Office in a technician onboarding review, the team observes: A site network outage is repaired, but follow-up documentation omits what changed and which devices were touched. The approved corrective action is: “Record the baseline, intervention, validation and follow-up actions in the ticket and change log.” Which result BEST demonstrates success?
- The table reports the targeted interface's administrative state and line protocol correctly.
- The remote session reaches the router through the approved protected path with access logs.
- The diagnosis identifies the local reachability failure instead of an assumed remote packet drop.
- The closing record permits another technician to reconstruct and verify the repair.
Explanation
Correct Answer
D:Correct. This is the required observable acceptance evidence for “Record the baseline, intervention, validation and follow-up actions in the ticket and change log.” at the fictional Sunrise Payment Office. It demonstrates correction of the original cause: Complete operational records support repeatability, auditing and preventing recurrence.
Incorrect Answers
A:That result is evidence for a separate corrective action, “Run show ip interface brief and identify interface addresses and up/down status.”. It does not establish the intended outcome “The closing record permits another technician to reconstruct and verify the repair.” for the fictional Sunrise Payment Office case.
B:That result is evidence for a separate corrective action, “Connect through the authorized VPN and least-privilege management route before opening SSH.”. It does not establish the intended outcome “The closing record permits another technician to reconstruct and verify the repair.” for the fictional Sunrise Payment Office case.
C:That result is evidence for a separate corrective action, “Read the source of the ICMP error and inspect route and ARP state on the client.”. It does not establish the intended outcome “The closing record permits another technician to reconstruct and verify the repair.” for the fictional Sunrise Payment Office case.
Question 716
The technician plans a correction for: At the fictional Sunrise Payment Office in a technician onboarding review, the team observes: A site network outage is repaired, but follow-up documentation omits what changed and which devices were touched. During “Record the baseline, intervention, validation and follow-up actions in the ticket and change log.”, which precaution MOST specifically prevents a related risk?
- Do not interpret a DNS-only failure as proof that the Ethernet link is broken.
- Do not confuse MAC table records with operating-system image information.
- Do not leave configuration changes undocumented after restoring service.
- Do not assume a hostname uniquely determines which NIC transmits a given flow.
Explanation
Correct Answer
C:Correct. This precaution prevents a second fault while applying “Record the baseline, intervention, validation and follow-up actions in the ticket and change log.” at the fictional Sunrise Payment Office. The required protection is “Do not leave configuration changes undocumented after restoring service.”; success still requires “The closing record permits another technician to reconstruct and verify the repair.”.
Incorrect Answers
A:This caution is appropriate for a separate failure pattern: A PC pings 8.8.8.8 successfully but cannot resolve a website name and the operator replaces its Ethernet cable. The principal adjacent risk here is controlled by “Do not leave configuration changes undocumented after restoring service.”.
B:This caution is appropriate for a separate failure pattern: A switch's Cisco IOS release and uptime are requested for a support case but the engineer runs show mac address-table and reports MAC entries as software versions. The principal adjacent risk here is controlled by “Do not leave configuration changes undocumented after restoring service.”.
D:This caution is appropriate for a separate failure pattern: A Linux host shows two IPv4 addresses on different NICs but a troubleshooter reads only its hostname to determine which address a route uses. The principal adjacent risk here is controlled by “Do not leave configuration changes undocumented after restoring service.”.
Question 717
A service desk receives this network finding: At the fictional Westport Transit Depot while checking a service ticket, the team observes: A help-desk analyst tests only from their office during a remote-site outage and concludes every remote device is healthy because local systems work. Which action MOST directly resolves the reported issue?
- Use the console for device CLI access and a proper Ethernet or WAN interface for normal data service.
- Compare tests at the impacted branch, its gateway, the provider handoff and the central service.
- Use show ip route and inspect the matching network and next-hop details.
- Use show interfaces status on the switch and note the affected port's operational state.
Explanation
Correct Answer
B:Correct. In the fictional Westport Transit Depot case, Fault isolation must consider the actual failing segment and test from affected and unaffected vantage points. The specified corrective action, “Compare tests at the impacted branch, its gateway, the provider handoff and the central service.”, directly targets that condition. Evidence of resolution: The evidence narrows the break to a particular link or administrative domain.
Incorrect Answers
A:That action addresses a different network issue: A field engineer plugs a console rollover cable into a router and expects the operating system to create a normal internet connection over the cable. The present fictional Westport Transit Depot finding instead needs “Compare tests at the impacted branch, its gateway, the provider handoff and the central service.”, verified by “The evidence narrows the break to a particular link or administrative domain.”.
C:That action addresses a different network issue: A technician wants to know the route selected for 10.40.0.0/16 but reads only show inventory and calls that a routing lookup. The present fictional Westport Transit Depot finding instead needs “Compare tests at the impacted branch, its gateway, the provider handoff and the central service.”, verified by “The evidence narrows the break to a particular link or administrative domain.”.
D:That action addresses a different network issue: A technician needs a quick view of which switch ports are connected or disconnected but the engineer dumps a full device configuration and misses the status overview. The present fictional Westport Transit Depot finding instead needs “Compare tests at the impacted branch, its gateway, the provider handoff and the central service.”, verified by “The evidence narrows the break to a particular link or administrative domain.”.
Question 718
Before changing settings, consider this issue: At the fictional Westport Transit Depot while checking a service ticket, the team observes: A help-desk analyst tests only from their office during a remote-site outage and concludes every remote device is healthy because local systems work. What is the MOST specific underlying cause?
- Fault isolation must consider the actual failing segment and test from affected and unaffected vantage points.
- Display filters change what is shown after capture; they do not delete already recorded packets.
- Management scripts should use appropriate authorized access and minimize changes when gathering diagnostics.
- Incorrect or stale DNS answers can direct an application to a wrong destination independently of local subnetting.
Explanation
Correct Answer
A:Correct. This mechanism fits the observed network symptom at the fictional Westport Transit Depot: Fault isolation must consider the actual failing segment and test from affected and unaffected vantage points. The corresponding remedy is “Compare tests at the impacted branch, its gateway, the provider handoff and the central service.”. Confirmation: The evidence narrows the break to a particular link or administrative domain.
Incorrect Answers
B:That cause belongs to a different case: A support worker uses a Wireshark display filter to hide TCP traffic and then claims that the filtered packets were never captured. The observed fictional Westport Transit Depot condition is specifically explained by “Fault isolation must consider the actual failing segment and test from affected and unaffected vantage points.”.
C:That cause belongs to a different case: A support engineer launches an ad hoc script that reconfigures every router to collect interface data without confirming whether read-only data is available. The observed fictional Westport Transit Depot condition is specifically explained by “Fault isolation must consider the actual failing segment and test from affected and unaffected vantage points.”.
D:That cause belongs to a different case: A workstation's name lookup returns an obsolete IP address and the technician changes its subnet mask instead of checking DNS. The observed fictional Westport Transit Depot condition is specifically explained by “Fault isolation must consider the actual failing segment and test from affected and unaffected vantage points.”.
Question 719
A reviewer evaluates a proposed repair for: At the fictional Westport Transit Depot while checking a service ticket, the team observes: A help-desk analyst tests only from their office during a remote-site outage and concludes every remote device is healthy because local systems work. The approved corrective action is: “Compare tests at the impacted branch, its gateway, the provider handoff and the central service.” Which result BEST demonstrates success?
- The result lists successive hops or reveals a boundary where probes stop receiving responses.
- The report distinguishes visible connection metadata from encrypted application payload.
- The interface counters reveal or exclude CRC, error and other physical symptoms correlated with the outage.
- The evidence narrows the break to a particular link or administrative domain.
Explanation
Correct Answer
D:Correct. This is the required observable acceptance evidence for “Compare tests at the impacted branch, its gateway, the provider handoff and the central service.” at the fictional Westport Transit Depot. It demonstrates correction of the original cause: Fault isolation must consider the actual failing segment and test from affected and unaffected vantage points.
Incorrect Answers
A:That result is evidence for a separate corrective action, “Run an available supported Linux traceroute-style command toward the target.”. It does not establish the intended outcome “The evidence narrows the break to a particular link or administrative domain.” for the fictional Westport Transit Depot case.
B:That result is evidence for a separate corrective action, “Inspect TLS handshake metadata and transport behavior rather than promising automatic plaintext disclosure.”. It does not establish the intended outcome “The evidence narrows the break to a particular link or administrative domain.” for the fictional Westport Transit Depot case.
C:That result is evidence for a separate corrective action, “Run show interfaces for the affected port and examine error, speed, duplex and line status evidence.”. It does not establish the intended outcome “The evidence narrows the break to a particular link or administrative domain.” for the fictional Westport Transit Depot case.
Question 720
The technician plans a correction for: At the fictional Westport Transit Depot while checking a service ticket, the team observes: A help-desk analyst tests only from their office during a remote-site outage and concludes every remote device is healthy because local systems work. During “Compare tests at the impacted branch, its gateway, the provider handoff and the central service.”, which precaution MOST specifically prevents a related risk?
- Do not transmit privileged management passwords over plain Telnet on untrusted links.
- Do not assume the IPv4 routing table contains learned per-port Ethernet MAC entries.
- Do not generalize local-office test success to an untested remote location.
- Do not assume every standalone Cisco device supports switch-stack-specific show commands.
Explanation
Correct Answer
C:Correct. This precaution prevents a second fault while applying “Compare tests at the impacted branch, its gateway, the provider handoff and the central service.” at the fictional Westport Transit Depot. The required protection is “Do not generalize local-office test success to an untested remote location.”; success still requires “The evidence narrows the break to a particular link or administrative domain.”.
Incorrect Answers
A:This caution is appropriate for a separate failure pattern: An administrator wants encrypted command-line access to a router but a trainee selects Telnet on an untrusted network. The principal adjacent risk here is controlled by “Do not generalize local-office test success to an untested remote location.”.
B:This caution is appropriate for a separate failure pattern: A switch is missing a workstation's MAC entry and the technician runs show ip route expecting it to show learned Ethernet source locations. The principal adjacent risk here is controlled by “Do not generalize local-office test success to an untested remote location.”.
D:This caution is appropriate for a separate failure pattern: A support case needs a chassis serial and switch-stack member number, but a trainee reads only interface status and invents both. The principal adjacent risk here is controlled by “Do not generalize local-office test success to an untested remote location.”.