CompTIA 220-1201 CompTIA A+ Certification Exam: Core 1 Exam Dumps and Practice Test Questions Set 2 Q16-30
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Question16
A technician is troubleshooting a desktop computer that suddenly started showing extremely slow performance. The user reports that applications take minutes to open, and the mouse cursor frequently freezes. The technician opens Task Manager and observes that the disk usage is constantly at 100%, even when no applications are actively running. The SMART status of the drive reports “Caution” with reallocated sectors increasing. What is the most likely cause of the system’s performance problems?
A) Failing hard drive
B) Insufficient RAM
C) Outdated GPU drivers
D) Disabled write caching
Answer: A
Explanation:
The issue described provides multiple strong clues pointing toward an imminent storage failure. Option A, failing hard drive, is the most likely cause because the SMART status shows a “Caution” alert with increasing reallocated sectors. Reallocated sectors indicate that portions of the disk have become unreadable and the hard drive has shifted data to spare sectors. When this number rises, it signals physical degradation of the drive surface. As the drive deteriorates, read/write operations slow dramatically, often resulting in the exact symptoms described: system-wide freezing, delayed application launches, constant high disk usage, and sluggish overall performance. CompTIA 220-1201 emphasizes that SMART monitoring is one of the most important diagnostic tools for identifying failing drives, and a “Caution” or “Warning” status is a red flag that should not be ignored.
Option B, insufficient RAM, can certainly cause slowdowns when memory is overloaded, but the critical observation is the SMART “Caution” alert combined with constant 100% disk usage. If RAM were the problem, one would observe high memory utilization rather than severe disk degradation indicators. While memory shortages can lead to heavy paging that increases disk activity, it does not cause SMART errors nor reallocated sectors. Option C, outdated GPU drivers, is unrelated to storage performance and would typically cause graphical glitches, application crashes, or display output issues, not universal system slowness tied to disk thrashing. Option D, disabled write caching, may reduce disk performance slightly, but it does not lead to reallocated sectors or SMART warnings, nor does it cause the level of system freeze described here. Write caching being disabled affects performance in specific workloads, not general system behavior in this extreme way. All evidence—including disk thrashing, SMART sector reallocation, freezing, and slow launches—aligns perfectly with failing hard drive conditions. Therefore, Option A is the correct and most complete explanation.
Question17
A laptop user complains that their system frequently disconnects from the Wi-Fi whenever they move to a different room in the building. When the technician inspects the laptop, they notice the Wi-Fi signal drops sharply even when moving just a short distance away from the router. Other devices maintain stable connectivity throughout the building. Which of the following is the most likely cause?
A) Loose or damaged internal Wi-Fi antenna
B) Incorrect SSID configuration
C) Router VLAN misconfiguration
D) Outdated DNS settings
Answer: A
Explanation:
In this case, the laptop’s Wi-Fi signal rapidly weakening even at short distances indicates a hardware-related issue with the device’s wireless reception. Option A, a loose or damaged internal Wi-Fi antenna, is the most likely cause. Laptops rely on small internal antennas embedded around the display bezel, and if these become loose, disconnected, or damaged, the system’s wireless card cannot properly transmit or receive signals. The immediate signal degradation when moving away from the router is a textbook sign of impaired antenna function. Since other devices work fine throughout the building, this eliminates network-side problems and narrows the cause to the laptop. CompTIA 220-1201 objectives include troubleshooting wireless connectivity issues by distinguishing between device-level antenna faults and network-wide configuration issues.
Option B, incorrect SSID configuration, would prevent connection to the network entirely or cause confusion between multiple networks of similar names, but it would not cause signal strength to drop drastically with distance. SSID settings do not affect wireless range. Option C, router VLAN misconfiguration, would cause access restrictions or prevent communication between network segments, but it would not affect the laptop’s ability to receive a strong signal. VLAN issues are logical networking problems, not physical RF strength problems. Option D, outdated DNS settings, affects name resolution and web browsing but does not influence RF signal strength or connectivity stability. DNS problems never cause sudden Wi-Fi disconnections when walking away from the router. Because the issue is directly correlated with physical distance and only affects one device, the internal Wi-Fi antenna fault is the best explanation, making Option A correct.
Question18
A user reports that their all-in-one inkjet printer is printing faded images and streaky text. The technician runs a test print and notices missing lines and uneven color output. Ink levels are full, but the printhead cleaning cycle does not improve the print quality. What is the most likely cause?
A) Clogged printhead nozzles
B) Wrong paper size selection
C) Faulty USB connection
D) Low-quality ink cartridges
Answer: A
Explanation:
The faded prints, missing lines, and streaking strongly suggest printhead-related problems. Option A, clogged printhead nozzles, is the most likely cause because inkjet printers rely on micro-nozzles to spray ink onto paper. Over time, these nozzles can become clogged due to dried ink, debris, or long periods of inactivity. Even when ink levels appear full, clogged nozzles prevent proper ink flow, leading to inconsistent patterns, missing areas, and reduced print quality. When a cleaning cycle fails to correct the issue, it further supports severe nozzle blockage, which often requires deep cleaning or manual maintenance. CompTIA 220-1201 includes printer troubleshooting topics where clogged printheads are a common cause of print quality degradation.
Option B, wrong paper size selection, causes misalignment or scaling issues but does not produce missing lines or uneven coloring. Even if the paper size were incorrect, the printer would still apply ink evenly. Option C, a faulty USB connection, affects communication between the printer and the computer. It may cause printing errors or failed jobs, but it does not impact the physical output consistency once printing begins. Option D, low-quality ink cartridges, may cause color inconsistency or faster fading over time, but it does not commonly result in complete missing lines or streaks unless the ink is defective. However, the symptoms described match clogged nozzles far more precisely. Therefore, Option A is the correct answer.
Question19
A technician is troubleshooting a desktop PC where the CPU temperature spikes to dangerously high levels immediately after booting into the operating system, causing the system to automatically shut down. Upon opening the case, they notice that the CPU cooler fan is spinning, but the heatsink feels loose. Which of the following is the most likely cause?
A) Improperly seated heatsink
B) Incorrect thermal paste application causing excess cooling
C) GPU overheating leading to CPU shutdown
D) Underpowered power supply
Answer: A
Explanation:
The CPU reaching extreme temperatures immediately after boot indicates a critical cooling failure. Option A, improperly seated heatsink, is the most likely cause because a loose heatsink cannot maintain proper thermal contact between the CPU and the cooling assembly. Even if the fan is spinning, if the heatsink is not firmly attached, heat cannot be transferred efficiently away from the CPU, resulting in rapid thermal spikes and system shutdown triggered by CPU protection mechanisms. The fact that the heatsink feels loose is a clear indicator of poor mounting pressure or broken clips. CompTIA 220-1201 exam content frequently covers heatsink mounting issues, thermal paste application, and cooling troubleshooting.
Option B, incorrect thermal paste application causing excess cooling, is incorrect because there is no scenario where improper thermal paste leads to too much cooling. Thermal paste problems cause overheating, not overcooling, and cannot explain a loose heatsink. Option C, GPU overheating, would not cause immediate CPU shutdown right after boot. GPU overheating usually occurs during heavy graphical loads, not at idle. Option D, underpowered power supply, causes random reboots or failure to power components, not immediate thermal shutdowns tied to CPU temperatures. The direct evidence of a loose heatsink makes Option A the most logical and accurate cause.
Question20
A user reports that their smartphone is charging extremely slowly. The technician tests multiple outlets and confirms that the issue occurs regardless of location. The charging cable and adapter work normally with another device. The technician observes that the phone becomes unusually warm during charging and the battery drains even while plugged in. What is the most likely cause?
A) Failing battery
B) Incorrect screen brightness settings
C) Outdated mobile OS
D) Disabled Bluetooth
Answer: A
Explanation:
The combination of slow charging, battery drain even when plugged in, and unusual heat strongly suggests internal battery deterioration. Option A, failing battery, is the most likely cause because lithium-ion batteries degrade over time and lose their ability to hold or accept charge efficiently. A failing battery may generate excess heat due to internal resistance, causing charging circuits to throttle charging speeds to prevent thermal runaway. This leads to slow charging or continued battery drain even while connected to power. The fact that the cable and charger work with other devices rules out power delivery problems. CompTIA 220-1201 includes mobile device troubleshooting, specifically identifying symptoms of failing batteries such as overheating, swollen casings, rapid discharge, and charging anomalies.
Option B, incorrect screen brightness settings, may drain the battery faster but would not explain slow charging or overheating during charge. Option C, an outdated mobile OS, could cause performance issues or app instability but does not directly impact charge rate to the extent described. An OS update rarely affects charging hardware functionality. Option D, disabled Bluetooth, has no correlation with charging or battery degradation. Bluetooth being off would reduce power consumption, not increase it. The clear and combined indicators—heat, slow charging, and drain—point unanimously toward a failing battery. Therefore, Option A is correct.
Question21
A user reports that their laptop intermittently disconnects from the corporate Wi-Fi whenever they move from one floor to another. Other devices maintain connectivity without issues. The technician notices that the wireless adapter is set to “Maximum Performance” but roaming aggressiveness is set to low. Which of the following is the most likely cause?
A) Wireless adapter roaming aggressiveness misconfiguration
B) DHCP server misconfiguration
C) Router SSID conflict
D) Faulty Ethernet adapter
Answer: A
Explanation:
This scenario involves diagnosing intermittent wireless connectivity issues that occur during physical movement between coverage zones. The key indicators are the device-specific problem, roaming between floors, and the adapter’s configuration settings. The wireless adapter’s roaming aggressiveness determines how readily it switches between access points as signal strength changes. When set too low, the adapter tends to cling to a weaker access point longer than optimal, resulting in frequent disconnections when the user moves into areas where signal strength diminishes. This is a classic scenario described in CompTIA 220-1201 objectives that focus on wireless troubleshooting, including identifying client-side settings as the root cause rather than network-wide issues. A properly configured roaming aggressiveness allows the adapter to select stronger access points proactively, maintaining seamless connectivity without dropping connections.
Option B, DHCP server misconfiguration, would result in IP conflicts, inability to obtain an IP address, or total network access failure, typically affecting multiple users rather than one specific device. Since other users on the same floor and network do not experience disconnections, DHCP is unlikely to be the source. DHCP problems produce persistent failures, whereas this problem is intermittent and mobility-related.
Option C, router SSID conflict, occurs when multiple networks broadcast the same SSID without coordination, potentially causing devices to jump between networks unpredictably. While this can cause connectivity issues, the symptom would likely affect all nearby devices or produce sporadic authentication errors. The isolated nature of the problem points toward a client-side misconfiguration rather than a network-wide SSID conflict.
Option D, a faulty Ethernet adapter, is irrelevant in this context because the problem occurs on Wi-Fi and the device is experiencing mobility-based disconnections. A failing Ethernet adapter would not influence wireless connectivity or roaming behavior. The wireless adapter’s roaming aggressiveness is the most accurate explanation, making Option A correct. Adjusting this setting ensures the laptop switches efficiently between APs, maintaining stable connectivity.
Question22
A desktop PC is experiencing extremely slow performance after upgrading from a traditional HDD to an SSD. The system boots quickly, but applications take unusually long to open. The technician confirms the SSD is installed correctly and recognizes the drive in BIOS. Which of the following is the most likely cause?
A) SSD connected to a slower SATA port
B) Improperly seated RAM
C) Excessive desktop icons
D) Corrupted restore point
Answer: A
Explanation:
The scenario describes a system where the operating system boots quickly, indicating that the SSD’s sequential read speeds are partially utilized. However, slow application launches point to bandwidth bottlenecks during random read/write operations. Option A, connecting the SSD to a slower SATA port, explains this issue. Many motherboards provide ports with different speeds, such as SATA II versus SATA III, or may route certain ports through additional controllers with lower throughput. Even a modern SSD connected to a port limited to 3Gbps cannot reach its potential performance, causing applications and other random-access operations to lag. This aligns directly with CompTIA 220-1201 objectives related to storage installation and performance troubleshooting. Verifying port speed in BIOS and ensuring connection to a maximum-speed port is the technician’s first step.
Option B, improperly seated RAM, would more likely cause general system instability, crashes, or failure to boot. While low memory can cause swapping to the pagefile, the scenario specifies high boot speed, which suggests sufficient memory for OS initialization. RAM issues alone are unlikely to produce this specific behavior.
Option C, excessive desktop icons, might slightly affect login times, but modern systems can handle hundreds of icons without impacting application launch times. The described lag is more indicative of hardware-level bottlenecks, not cosmetic OS elements.
Option D, corrupted restore point, is irrelevant after a fresh OS installation and restoration. Restore points influence system rollback operations, not normal performance during application use. Therefore, Option A is the most logical explanation, and the solution involves confirming port capabilities and, if necessary, relocating the SSD to a higher-speed interface.
Question23
A desktop system intermittently shuts down while running video editing software or games. The system runs fine under light workloads. The technician opens the case and finds the GPU is dusty, with airflow partially blocked. Which of the following is the most likely cause?
A) Overheating GPU due to dust buildup
B) Incorrect display resolution
C) Faulty keyboard sending shutdown signals
D) Outdated printer drivers
Answer: A
Explanation:
The system behavior indicates that high GPU utilization triggers shutdowns, which is characteristic of thermal protection mechanisms in modern graphics cards. Option A, an overheating GPU due to dust buildup, explains the symptom. GPUs generate substantial heat under load, and inadequate airflow, clogged fans, or dust accumulation can prevent proper cooling. When GPU temperatures exceed safe thresholds, systems often trigger automatic shutdowns to prevent permanent hardware damage. CompTIA 220-1201 objectives specifically reference thermal troubleshooting, emphasizing identification of overheating components, inspection for dust accumulation, fan function verification, and cleaning procedures. The correlation between workload intensity and shutdown timing further supports a thermal cause rather than a general hardware failure.
Option B, incorrect display resolution, may cause visual artifacts or UI scaling issues but does not produce system shutdowns. Display configuration does not affect thermal load to the extent that it would initiate protective shutdowns.
Option C, a faulty keyboard sending shutdown signals, is unlikely because keyboard faults manifest as stuck keys, repeated input, or failure to respond. Modern motherboards do not interpret errant keyboard signals as commands to power down the system. This explanation does not match the workload-dependent symptom pattern.
Option D, outdated printer drivers, does not influence GPU performance or thermal behavior. Printer drivers primarily impact printing operations and would not cause intermittent system shutdowns during graphics-intensive applications. Therefore, Option A is the only explanation consistent with observed behavior, thermal evidence, and CompTIA-recommended diagnostic methodology.
Question24
A smartphone’s battery drains rapidly after a recent OS update. The user reports the device becomes warm even during light use, and charging does not restore battery life effectively. Which of the following should the technician check FIRST?
A) Battery usage statistics for high-drain apps
B) Replace the battery immediately
C) Reinstall the OS completely
D) Disable all wireless radios permanently
Answer: A
Explanation:
The scenario indicates a post-update battery drain issue, combined with device heating during normal usage. The first logical diagnostic step is examining battery usage statistics (Option A). Modern mobile operating systems provide detailed analytics showing which applications or system processes consume the most power. Post-update behavior may cause background tasks to run excessively, apps to malfunction, or processes to enter high-frequency cycles, all contributing to rapid discharge. Checking usage statistics allows the technician to identify abnormal power consumption without taking irreversible actions like battery replacement or OS reinstallation. CompTIA 220-1201 covers mobile device troubleshooting, emphasizing diagnostic sequencing: begin with non-invasive analysis before hardware replacement.
Option B, immediate battery replacement, is premature. Although aging batteries eventually fail, the scenario notes that the issue appeared after an OS update, suggesting a software-related cause. Replacing the battery before analyzing usage patterns risks unnecessary cost and may not resolve the root issue.
Option C, reinstalling the OS, is a more drastic step and should follow identification of abnormal processes or app behaviors. OS reinstallation is time-consuming and may result in data loss if not carefully managed. It is not the first step in systematic troubleshooting.
Option D, disabling all wireless radios, may reduce battery drain but is impractical as it severely limits device functionality. Additionally, the root cause may be unrelated to radio usage, so this action could mask symptoms without resolving the underlying problem. Therefore, checking battery usage statistics is the most efficient and effective first step.
Question25
A technician is configuring a small office wireless network. The user requests strong security but minimal administrative complexity. Which of the following wireless security options should the technician select?
A) WPA3-Personal
B) Open Wi-Fi
C) WEP
D) Hidden SSID only
Answer: A
Explanation:
In configuring a SOHO wireless network, balancing security and convenience is critical. Option A, WPA3-Personal, provides the strongest modern encryption standard for personal and small business environments. It offers robust protection against password cracking, enhanced encryption algorithms, and forward secrecy, improving protection for both data in transit and authentication processes. WPA3-Personal requires minimal configuration beyond setting a passphrase, aligning with the user’s requirement for low administrative complexity. CompTIA 220-1201 objectives highlight selecting appropriate wireless security protocols for small networks, emphasizing WPA2 or WPA3 over legacy or insecure options.
Option B, Open Wi-Fi, offers no encryption and allows any device to connect without credentials. While convenient, it exposes all traffic to interception and unauthorized access. This configuration is unacceptable when security is a priority.
Option C, WEP, is an outdated encryption protocol with severe vulnerabilities, including easily cracked keys and poor data protection. Although historically common, WEP is no longer recommended under any circumstances, particularly when strong security is required.
Option D, hiding the SSID, does not provide encryption or true security. It merely obscures the network name, which can be easily discovered with scanning tools. Hiding the SSID is insufficient as a primary security measure and should never be relied upon alone. Therefore, WPA3-Personal is the only option that effectively balances strong encryption, modern security standards, and minimal administrative overhead.
Question26
A user reports that their laptop is unable to print to a network printer. Other users on the same network can print without issue. The technician verifies that the laptop has the correct printer driver installed and can ping the printer successfully. Which of the following is the most likely cause?
A) Incorrect firewall settings on the laptop
B) Printer out of paper
C) Loose network cable at the printer
D) Wrong USB port selected
Answer: A
Explanation:
In this scenario, the laptop is uniquely affected, while other devices on the same network experience no printing problems. The fact that the driver is installed correctly and network connectivity to the printer is verified eliminates many hardware and driver-related issues. Option A, incorrect firewall settings on the laptop, is the most likely cause. Modern operating systems include firewalls that can block certain network ports or applications. Network printing requires communication over specific ports such as TCP 9100, LPR/LPD (TCP 515), or Windows Printer Sharing (TCP 445, SMB). If the firewall is configured to block these ports or the print spooler application is not permitted through the firewall, the print jobs will not reach the printer, even though connectivity tests like ping succeed. This aligns with CompTIA 220-1201 objectives regarding troubleshooting printing issues, including differentiating between network connectivity, driver, and system configuration problems.
Option B, the printer being out of paper, would prevent printing for all users, not just the single laptop in question. Additionally, the user report and the successful pings indicate that the printer is powered on and accessible. This eliminates the paper-related cause.
Option C, a loose network cable at the printer, would cause the printer to be unreachable entirely. Since other users are printing successfully, this is not applicable. A loose cable affects the device physically and is not device-specific in terms of preventing one laptop from printing.
Option D, the wrong USB port selected, is irrelevant because the user is attempting to print to a network printer, which relies on network connectivity rather than a physical USB connection. USB port selection only affects direct-connected printers. Therefore, Option A provides the best explanation. Correcting firewall rules to allow print jobs to traverse the network resolves the issue efficiently, following proper diagnostic methodology as outlined in the CompTIA objectives.
Question27
A desktop PC is producing a continuous single beep during startup, and the display remains blank. The technician confirms that the monitor works with another system. Which of the following is the most likely cause?
A) Faulty RAM module
B) Incorrect display resolution
C) Loose CPU power connection
D) Damaged hard drive
Answer: A
Explanation:
A single continuous beep during POST is a strong diagnostic signal, typically indicating memory issues. Option A, a faulty RAM module, is the most likely cause. During the POST sequence, the motherboard checks the presence and integrity of RAM. If RAM is missing, improperly seated, or faulty, the BIOS emits beep codes to alert the user. The display remains blank because the system cannot initialize memory to load the BIOS routines fully. This behavior is consistent with CompTIA 220-1201 objectives, which emphasize understanding POST codes and identifying hardware failure patterns.
Option B, incorrect display resolution, would not prevent POST from completing. Display resolution settings are irrelevant until the operating system or BIOS initialization accesses video output. Resolution misconfigurations affect screen clarity or UI scaling, not system boot or beep codes.
Option C, a loose CPU power connection, can prevent startup and may cause power issues. However, loose CPU power typically results in a complete failure to power on, fan inactivity, or random shutdowns. The presence of beep codes specifically points to a memory issue rather than general power distribution failure.
Option D, a damaged hard drive, would not prevent POST or produce continuous beep codes. Hard drives are accessed after BIOS initialization and do not affect the basic memory checks. System boot failure due to a hard drive issue would occur later in the boot sequence, often producing OS-level errors rather than POST beep codes. Therefore, the faulty RAM module is the most precise explanation. The correct troubleshooting step is to reseat the memory modules or replace faulty RAM, restoring system startup functionality.
Question28
A user complains that their laptop battery is discharging rapidly even when not in use. The technician confirms that all background applications have been closed, and screen brightness is minimized. Which of the following should the technician check first?
A) Battery health and calibration status
B) Reinstalling the operating system
C) Turning off Bluetooth and Wi-Fi permanently
D) Replacing the laptop screen
Answer: A
Explanation:
The problem indicates abnormal power drain on the laptop despite minimal usage. Option A, checking battery health and calibration, is the first logical step. Lithium-ion batteries degrade over time, losing their capacity to hold charge efficiently. A degraded battery may discharge rapidly even without active applications running. Battery calibration ensures that the operating system accurately reports charge levels. This aligns with CompTIA 220-1201 objectives under mobile device troubleshooting, where battery diagnostics and health assessment are essential first steps in identifying power-related issues.
Option B, reinstalling the operating system, is unnecessary as the issue is hardware-related. Software reinstalls may resolve application-related power drains but will not correct a failing battery or inaccurate calibration. OS reinstallation is a drastic measure and should follow hardware verification.
Option C, turning off Bluetooth and Wi-Fi permanently, may reduce power usage slightly but is impractical and does not address the root cause. Even with wireless radios disabled, a failing battery can continue to discharge rapidly. This option does not adhere to proper diagnostic methodology because it does not involve identifying the underlying issue.
Option D, replacing the laptop screen, is unrelated. While screens consume power, the user has minimized brightness, and the drain persists. There is no evidence indicating display malfunction contributes to battery drain. Therefore, Option A is correct, and the technician should run a battery health check and recalibration procedure before considering replacements or software fixes.
Question29
A desktop PC fails to boot, and the power LED flashes in a repeating pattern. The technician observes that the fans are spinning, but the monitor remains blank. Which of the following is the most likely cause?
A) Power supply failure
B) Faulty GPU
C) Incorrect display resolution
D) Loose keyboard connection
Answer: A
Explanation:
Flashing LEDs combined with non-booting behavior are common indicators of hardware failure. Option A, power supply failure, is the most likely cause. While fans may spin due to residual voltage, the motherboard and CPU may not receive stable power necessary for POST, preventing initialization of system components and resulting in flashing LEDs as a diagnostic signal. This is consistent with CompTIA 220-1201 troubleshooting objectives that describe power-related startup issues, including understanding indicator patterns and isolating components affected by insufficient power.
Option B, a faulty GPU, may prevent display output but does not typically result in flashing LEDs on the motherboard indicating a complete power-related fault. A GPU failure would likely trigger POST beep codes or artifacting but leave the system powered on.
Option C, incorrect display resolution, cannot prevent system POST. Display settings take effect only after the operating system loads; they do not impact initial boot sequences or motherboard LED indicators.
Option D, loose keyboard connection, may cause BIOS errors in some cases but would not prevent POST entirely. Keyboard disconnection does not disrupt motherboard power distribution or CPU initialization. Therefore, Option A is correct, and the technician should test the power supply using a multimeter or replace it to restore proper functionality.
Question30
A user reports that their wireless router allows devices to connect but blocks internet access. The technician verifies that all devices obtain IP addresses and can communicate with each other locally. Which of the following is the most likely cause?
A) Incorrect WAN configuration or ISP connectivity
B) Devices are using static IPs on the LAN
C) Router SSID is hidden
D) Ethernet cables are faulty
Answer: A
Explanation:
This scenario describes a network where LAN connectivity works, but internet access is unavailable. Option A, incorrect WAN configuration or ISP connectivity, is the most likely cause. Devices can communicate locally because the LAN is functioning, indicating the router’s DHCP and switch functions are operational. However, if the router’s WAN interface is misconfigured—incorrect gateway, DNS settings, or ISP authentication failure—traffic to the internet is blocked. CompTIA 220-1201 objectives emphasize verifying WAN settings, testing ISP connectivity, and isolating problems between LAN and WAN when diagnosing network failures.
Option B, static IP usage, may cause local conflicts if misconfigured but does not prevent internet access if correct gateway and DNS settings are in place. Since devices can communicate locally, this option does not explain the total loss of internet connectivity.
Option C, a hidden SSID, affects network visibility but does not block access once devices are connected. Devices connected to a hidden SSID still route traffic normally, so hiding the SSID is not the cause of blocked internet.
Option D, faulty Ethernet cables, would prevent LAN connectivity entirely. Since devices can communicate locally, cable integrity is confirmed. Therefore, Option A is the accurate diagnosis. The technician should verify router WAN settings, test ISP reachability, and ensure correct DNS and gateway configurations to restore internet access.
In this scenario, the network shows an interesting distinction between local connectivity and internet access. The fact that devices on the LAN can communicate with each other indicates that the internal network is functioning correctly. This means that the physical infrastructure, such as Ethernet cabling, network switches, and wireless access points, is operational. It also suggests that the router’s internal routing and DHCP services are working properly, allowing devices to receive IP addresses, communicate with one another, and access shared resources on the LAN. The problem arises when these same devices attempt to access the internet and fail to do so. This situation points to an issue outside the local network, specifically in the wide area network connection or the router’s configuration connecting the LAN to the internet.
Option A, incorrect WAN configuration or ISP connectivity, is the most likely explanation. The WAN interface of a router acts as the bridge between the local network and the external internet. If the WAN interface is misconfigured, the router cannot properly route traffic from the internal network to the ISP and, subsequently, to the broader internet. Misconfiguration could involve incorrect IP addressing, subnet masks, default gateway information, or DNS settings. If the router does not have the correct gateway assigned, it will be unable to send outbound traffic to the ISP. Even if devices on the LAN are receiving correct internal IP addresses, they will not be able to reach external networks because the router itself does not know how to route the traffic. In addition, some ISPs require authentication protocols such as PPPoE. If the router fails to authenticate with the ISP using the correct credentials, it will be unable to establish a WAN connection, resulting in a complete loss of internet access. This is consistent with the scenario where the LAN functions correctly but the internet is inaccessible. Troubleshooting in this situation requires checking the WAN interface settings, verifying that the IP address and subnet match the ISP requirements, confirming the default gateway, ensuring DNS servers are correctly configured, and verifying ISP credentials where needed. It may also involve contacting the ISP to confirm that service is active and that there are no external outages affecting connectivity.
Option B, the use of static IP addresses, is less likely to be the cause in this scenario. While static IP addresses can sometimes lead to conflicts or misconfigurations, if devices are able to communicate locally, this indicates that the static IPs are correctly configured at least for the LAN. A device with a static IP can still access the internet if it has the correct default gateway and DNS settings. The total loss of internet access for all devices suggests a problem at the WAN level rather than an IP configuration issue on individual devices. Static IP configuration would only become a potential factor if the default gateway was incorrectly set, but the scenario does not provide any indication of gateway misassignment, and the fact that all devices experience the same problem further points to the router’s WAN interface rather than individual device misconfiguration. Therefore, while static IPs must always be verified during troubleshooting, in this case, they are unlikely to be the root cause.
Option C, a hidden SSID, also does not account for the internet connectivity problem. A hidden SSID simply means that the network name is not broadcast publicly, requiring devices to manually configure the SSID to connect. This affects network visibility and initial connection but has no impact on traffic routing once a device is connected. Since the scenario states that devices can communicate on the LAN, they are clearly connected to the network. Once connected, a hidden SSID does not block access to the internet or interfere with the router’s routing capabilities. Therefore, hiding the SSID cannot explain the complete loss of internet access experienced by all devices.
Option D, faulty Ethernet cables, is inconsistent with the observed network behavior. Faulty cabling typically results in no connection or intermittent connectivity on the LAN. Symptoms of cable issues include devices failing to obtain IP addresses, inability to communicate with other devices on the same network, and lights on the network interface or switch ports not illuminating correctly. In this scenario, devices communicate successfully on the LAN, which confirms that the physical cabling and ports are operational. Since the problem is isolated to internet access rather than local connectivity, damaged Ethernet cables can be ruled out as the cause.
The key to understanding this problem is to recognize the separation between LAN and WAN functionality. Local communication indicates that the router is functioning as a DHCP server and switch, distributing IP addresses correctly and allowing devices to exchange data internally. The failure of internet access points specifically to the WAN side of the network. WAN troubleshooting typically involves checking the router’s connection to the ISP, verifying IP address assignment and gateway settings, and testing connectivity to external IP addresses. A technician would first check the router’s WAN interface to confirm that it has received a valid IP address. If the IP is missing, incorrect, or conflicts with another device, the router will be unable to route traffic outside the LAN. Next, the technician would verify the default gateway, which directs all outbound traffic toward the ISP. Incorrect gateway configuration effectively isolates the LAN from the internet while leaving internal communication unaffected. DNS verification is also crucial because even if the WAN interface is functional and the router has connectivity to the ISP, devices will not be able to resolve domain names if the DNS is misconfigured.
Testing ISP connectivity may involve attempting to ping known external IP addresses. Successful pings indicate that the router can reach external networks, and the problem may then lie in DNS configuration. Failure to ping external addresses confirms a WAN-level problem that requires further investigation of the router settings or ISP support. The technician may also consider checking for service outages from the ISP. Sometimes the router and local configuration are correct, but the ISP experiences downtime or network failures that prevent internet access. In such cases, waiting for the ISP to restore service or contacting technical support becomes necessary.
Ultimately, the scenario emphasizes the importance of methodical troubleshooting. By understanding the difference between LAN and WAN issues, a technician can avoid unnecessary changes to the local network and focus on the interface that is actually malfunctioning. The steps include verifying the WAN interface, checking for proper IP addressing and gateway assignment, ensuring DNS servers are correct, confirming ISP authentication, and testing connectivity to external resources. These procedures align with CompTIA 220-1201 objectives, which require technicians to isolate and diagnose network connectivity issues using logical steps rather than assumptions.
Another aspect to consider is the role of DNS servers. While a WAN connection may exist, improperly configured DNS can give the appearance of a complete internet outage. Devices may be able to ping external IP addresses successfully but fail to access websites because the domain names cannot be resolved to IP addresses. In many networks, routers automatically assign ISP-provided DNS addresses to connected devices via DHCP. If the router’s DNS configuration is incorrect or if the ISP’s DNS servers are temporarily unavailable, users may perceive total internet loss despite an otherwise functional WAN connection. A technician may verify DNS functionality by manually setting a known public DNS server, such as Google’s 8.8.8.8 or Cloudflare’s 1.1.1.1, to test whether domain resolution restores internet access.