220-1201 Hard Questions — 25 Difficult Questions

Question 1

A company's network uses a managed switch with VLANs. Users in VLAN 10 can ping the default gateway but cannot communicate with users in VLAN 20. The switch is connected to a router that handles inter-VLAN routing. What is the most likely misconfiguration?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

The switch port connecting to the router is configured as an access port instead of a trunk.. The most likely misconfiguration is that the switch port connecting to the router is configured as an access port instead of a trunk. For inter-VLAN routing to work, the router must receive traffic from multiple VLANs on the same physical interface. A trunk port (using 802.1Q tagging) allows frames from VLAN 10 and VLAN 20 to be forwarded to the router, which then routes between them. An access port can only carry traffic for a single VLAN, so frames from VLAN 20 would be dropped or misdirected, preventing communication.

Answer

The router's firewall is blocking traffic between VLANs.

Answer

The default gateway for VLAN 20 is misconfigured.

Answer

The switch has Spanning Tree Protocol enabled, blocking the link.

Question 2

A user has a laptop that supports Thunderbolt 3 and wants to connect two external 4K monitors at full resolution. They currently have a single USB-C hub that only supports DisplayPort over USB-C. What is the most likely limitation?

Accepted Answer

The hub does not support Thunderbolt 3 bandwidth.. Thunderbolt 3 supports up to 40 Gbps bandwidth, which is required to drive two 4K monitors at full resolution (60 Hz) over a single connection. A standard USB-C hub that only supports DisplayPort over USB-C is limited to USB 3.1 Gen 2 (10 Gbps) or USB 3.2 (20 Gbps) bandwidth, which is insufficient to carry two uncompressed 4K video streams simultaneously. Therefore, the hub itself is the bottleneck because it lacks Thunderbolt 3 controller and bandwidth capabilities.

Answer

The laptop's graphics card cannot drive two 4K monitors.

Answer

The monitors are not compatible with USB-C.

Answer

The user needs a USB-C to HDMI adapter for each monitor.

Question 3

A technician is setting up a temporary network for a conference where attendees' laptops need to share files directly without any central access point or router. The conference room has no existing network infrastructure. Which network type should be configured, and what is a potential security risk?

Accepted Answer

Ad hoc network; each laptop connects directly to others, but encryption may not be enforced.. An ad hoc network (IBSS) allows laptops to communicate directly without a central access point, which matches the requirement for direct file sharing with no existing infrastructure. The security risk is that encryption (like WEP or WPA2-Personal) may not be enforced by default in ad hoc mode, leaving data transmissions vulnerable to eavesdropping.

Answer

Infrastructure mode WLAN; configure a laptop as a software access point.

Answer

PAN network using Bluetooth; all laptops pair via Bluetooth.

Answer

Mesh network; each laptop acts as a node forwarding traffic.

Question 4

A technician is troubleshooting an iPhone that cannot install or update any apps from the App Store. The device is connected to Wi-Fi, and other internet services (Safari, email) work. What should the technician check first?

Accepted Answer

Verify that the Apple ID is signed in and has no payment issues.. The most common cause for an iPhone being unable to install or update apps while other internet services work is an issue with the Apple ID, such as a payment method that has expired or a billing problem. The App Store requires a valid payment method on file even for free apps, and the device will block downloads until the account is resolved. Since Safari and email function normally, the network connectivity is fine, narrowing the issue to account authentication or authorization.

Answer

Check if the date and time are set correctly on the iPhone.

Answer

Reset the iPhone's network settings.

Answer

Check if the iPhone is in Low Power Mode.

Question 5

A technician is configuring a router with two interfaces: WAN (DHCP from ISP) and LAN (static IP 10.0.0.1/24). The technician sets the LAN subnet mask to 255.255.255.0. A workstation is assigned IP 10.0.0.100/24 and can ping the router, but cannot access the internet. The router's WAN interface has IP 203.0.113.5/30. What is the most likely missing configuration?

Accepted Answer

The router lacks a default route pointing to the ISP's gateway.. The workstation can ping the router's LAN interface (10.0.0.1), confirming Layer 2 and basic IP connectivity on the LAN. However, for the workstation to reach the internet, the router must have a default route (0.0.0.0/0) pointing to the ISP's next-hop gateway (likely 203.0.113.6, the other end of the /30 WAN link). Without this route, the router does not know where to forward packets destined for external networks, even though the WAN interface has a valid IP from DHCP.

Answer

The workstation's default gateway is set to 10.0.0.1.

Answer

The WAN subnet mask should be 255.255.255.0.

Answer

The LAN subnet mask should be 255.255.0.0.

Question 6

A user's smartphone can connect to a corporate Wi-Fi network but cannot access any internet sites. Other devices on the same network work fine. The smartphone shows it is connected with full signal. What is the most likely cause?

Accepted Answer

The smartphone's DNS settings are misconfigured or pointing to a non-functional server.. The smartphone can connect to the Wi-Fi network (Layer 2 connectivity is fine) and other devices work, so the issue is specific to this device's higher-layer configuration. DNS resolution is required to translate domain names to IP addresses; if the smartphone's DNS settings point to a non-functional or incorrect server, it will fail to resolve any hostname, preventing internet access even though the network connection itself is active. This matches the symptom of being connected with full signal but unable to browse.

Answer

The corporate network is blocking the smartphone's MAC address.

Answer

The smartphone's Wi-Fi adapter is faulty.

Answer

The corporate proxy server is down.

Question 7

A user complains that their wireless Bluetooth earbuds frequently disconnect during calls when their smartphone is in their pocket. The earbuds work fine when the phone is on a desk. Which accessory or configuration change is most likely to resolve this issue?

Accepted Answer

A Bluetooth neckband style headset. The issue is that the smartphone's Bluetooth antenna is being physically blocked or attenuated by the user's body (specifically the leg/torso) when the phone is in a pocket. A Bluetooth neckband-style headset places the Bluetooth receiver and antenna around the user's neck, which is typically above the pocket and has a clearer line-of-sight to the phone, significantly reducing signal obstruction and multipath interference. This configuration change directly addresses the physical signal path problem without requiring any software or network changes.

Answer

A Bluetooth signal booster app

Answer

A metal phone case

Answer

A Wi-Fi analyzer to change router channels

Question 8

A technician is deploying a new server that requires RAID 10 for data redundancy and performance. The motherboard has an onboard RAID controller. After configuring the RAID array in the UEFI RAID utility, the technician installs the OS, but the RAID volume is not visible in the OS installer. What is the most likely cause?

Accepted Answer

The RAID driver is missing from the OS installation media.. The RAID volume is configured in the UEFI RAID utility, but the OS installer cannot see it because the installer lacks the driver for the onboard RAID controller. During Windows installation, the setup environment only includes drivers for common storage controllers; if the RAID controller is not natively supported, the volume will not appear until the driver is loaded. The technician must provide the driver via USB or other media during installation.

Answer

The RAID array was not properly initialized in the UEFI RAID utility.

Answer

The SATA mode is set to AHCI instead of RAID in the UEFI.

Answer

The UEFI boot mode is set to Legacy, which does not support RAID.

Question 9

A technician is troubleshooting a network where users can access internal resources but cannot reach any external websites. The internal network uses a proxy server. The technician finds that the proxy server is configured to use a specific protocol to forward requests to the internet. Which protocol is the proxy server most likely using to communicate with external web servers?

Accepted Answer

HTTP. The proxy server is most likely using HTTP (Hypertext Transfer Protocol) to forward requests to external web servers. Since users are accessing internal resources but cannot reach external websites, the proxy server acts as an intermediary for web traffic. HTTP is the standard protocol for web communication, and proxy servers typically use HTTP (or HTTPS) to forward client requests to internet web servers, as it allows the proxy to cache, filter, and modify web traffic.

Answer

FTP

Answer

DNS

Answer

SNMP

Question 10

A data center technician is installing a new server that requires a redundant power supply with two C13 power cords. The rack has two separate PDUs (Power Distribution Units) with C19 outlets. What type of power cable is needed to connect the server to the PDUs?

Accepted Answer

C13 to C19 power cord. The stem states the server requires 'C13 power cords,' which implies the server has C14 male inlets. Therefore, the cable must have a C13 female connector on the server end. The stem states the PDU has 'C19 outlets,' which are C19 female receptacles. To connect to a C19 female outlet, the cable must have a C20 male plug on the PDU end. Thus, the required cable is a C13 (female) to C20 (male) power cord. None of the provided options match this requirement.

Answer

C14 to C19 power cord

Answer

C13 to C14 power cord

Answer

C19 to C20 power cord

Question 11

A technician is troubleshooting a laptop that shuts down randomly after a few minutes of use. The fan is spinning, and the vents are clear. The CPU temperature reaches 95°C quickly. What is the most likely cause?

Accepted Answer

The thermal paste between the CPU and heatsink has dried out.. High CPU temperature despite a spinning fan indicates poor thermal transfer, often due to dried-out thermal paste or a heatsink that is not making proper contact. Reapplying thermal paste and reseating the heatsink is the solution. The fan working rules out a fan failure.

Answer

The fan is running at low speed due to a faulty fan controller.

Answer

The CPU is faulty and needs replacement.

Answer

The BIOS is set to an aggressive power-saving mode.

Question 12

A user reports that their laptop screen suddenly went black, but the laptop is still powered on (fans running, power light on). Connecting an external monitor shows the desktop correctly. What is the most likely cause?

Accepted Answer

The laptop's LCD inverter or backlight has failed.. The external display working normally indicates the GPU and OS are functional. The black built-in display points to a failure in the LCD panel, backlight, or the display cable (e.g., LVDS/eDP ribbon cable) connecting the motherboard to the screen. A loose or damaged internal cable is a common cause, especially in laptops that have been moved frequently.

Answer

The graphics driver has crashed and needs to be reinstalled.

Answer

The Windows display settings are set to 'Show only on external display'.

Answer

The laptop's RAM is faulty and causing video output issues.

Question 13

A user reports that their Android tablet's screen flickers when using a specific video streaming app, but the screen is stable in other apps and on the home screen. What hardware component is most likely at fault?

Accepted Answer

The video streaming app has a software bug or codec issue.. The screen flickers only within a specific video streaming app, while the home screen and other apps remain stable. This strongly indicates the issue is isolated to software, specifically a bug or codec incompatibility within that app, rather than a hardware failure affecting the entire display or GPU.

Answer

The tablet's display panel is failing.

Answer

The GPU (Graphics Processing Unit) is overheating.

Answer

The tablet's battery is swollen and pressing on the display.

Question 14

A technician is troubleshooting a laptop that connects to a Wi-Fi network but gets a 'No Internet, Secured' message. The laptop has a static IP address configured. What is the most likely issue?

Accepted Answer

The laptop's static IP address is not in the same subnet as the router.. A static IP address that is not in the same subnet as the router prevents the laptop from communicating with the default gateway. Even though the Wi-Fi association succeeds (hence 'Secured'), the laptop cannot route traffic to the internet because it cannot reach the router's IP address. This mismatch causes the 'No Internet' message while the link-layer connection remains intact.

Answer

The Wi-Fi network's SSID is hidden.

Answer

The laptop's Wi-Fi driver is corrupted.

Answer

The router's DHCP server is disabled.

Question 15

A network administrator needs to connect two switches that are 200 meters apart. The connection must support 1 Gbps speed. The administrator has Cat5e cable available. However, Cat5e is only rated for 100 meters at 1 Gbps. Which device can be used to extend the distance without replacing the cable?

Accepted Answer

Network extender (repeater). A network extender (repeater) regenerates the electrical signal, allowing a Cat5e segment to exceed the 100-meter distance limitation while maintaining 1 Gbps speed. Since the administrator already has Cat5e cable and only needs to extend the reach, a repeater operates at Layer 1 to boost the signal without replacing the cable.

Answer

Media converter

Answer

PoE injector

Answer

Load balancer

Question 16

A user complains that their external monitor connected via VGA shows a slightly blurry image with faint horizontal lines. The monitor works perfectly with another computer using the same VGA cable. What is the most likely cause?

Accepted Answer

There is a ground loop between the computer and monitor. The faint horizontal lines and blurry image are classic symptoms of a ground loop, where a difference in electrical potential between the computer and monitor causes interference on the analog VGA signal. Since the monitor works perfectly with another computer using the same cable, the cable and monitor are exonerated, isolating the issue to the computer's grounding or power supply.

Answer

The monitor's resolution is set too high for VGA

Answer

The VGA port on the computer has bent pins

Answer

The graphics driver is corrupt

Question 17

A technician is troubleshooting a wireless network where users report intermittent connectivity and slow speeds. A spectrum analyzer shows high noise levels on the 2.4 GHz band from non-Wi-Fi sources. Which of the following is the MOST effective long-term solution?

Accepted Answer

Move all critical devices to the 5 GHz band.. The 5 GHz band has significantly more non-overlapping channels and is far less congested by non-Wi-Fi interference (e.g., microwaves, Bluetooth, cordless phones) than the 2.4 GHz band. Moving critical devices to 5 GHz avoids the interference source entirely, providing a stable long-term solution without compromising throughput or reliability.

Answer

Reduce the 2.4 GHz channel width to 20 MHz.

Answer

Implement DFS channels on the 5 GHz band.

Answer

Increase the transmit power on the 2.4 GHz radio.

Question 18

A technician is configuring a network for a new branch office. The branch has 50 users and needs to access resources at the main office via a secure tunnel over the internet. Which service is required to establish this connection?

Accepted Answer

VPN. A VPN (Virtual Private Network) is required to create a secure, encrypted tunnel over the internet between the branch office and the main office. This allows the 50 users to access internal resources at the main office as if they were on the same local network, using protocols such as IPsec or SSL/TLS to ensure confidentiality and integrity of data in transit.

Answer

DHCP

Answer

DNS

Answer

NAT

Question 19

A user reports that their laser printer prints pages with a repeating horizontal band of missing text about every 3 inches. The printer has a new toner cartridge and the drum is separate. What is the most likely cause?

Accepted Answer

The drum unit has a scratch or defect. A repeating horizontal defect at a fixed interval (here, every 3 inches) is the classic signature of a physical defect on a rotating component whose circumference matches that interval — most commonly the drum unit. Since the drum is separate from the toner cartridge and the toner is new, the scratch or debris on the drum surface is the most likely cause.

Answer

The fuser is not reaching the correct temperature

Answer

The toner cartridge is defective

Answer

The paper is damp or of poor quality

Question 20

A technician is diagnosing a system that fails to boot after a CPU upgrade. The old CPU worked fine. The new CPU is installed correctly, but the system beeps repeatedly (1 long, 3 short). Which of the following is the most likely issue?

Accepted Answer

The RAM is incompatible with the new CPU. 1 long, 3 short beeps from an AMI BIOS typically indicate a memory error. After a CPU upgrade, the existing RAM might be incompatible with the new CPU's memory controller or its supported memory speeds/types, leading to a memory error.

Answer

The CPU is not receiving power

Answer

The motherboard BIOS does not support the new CPU

Answer

The CPU cooler is not installed properly