220-1101 Networking Practice Test 11 — 15 Questions

Question 1

A technician is troubleshooting a small office network. Users on one side of the office report very slow network speeds and occasional disconnections. The technician checks the unmanaged switch and notices that the link LED for the port connected to a particular workstation is rapidly alternating between green and amber. The workstation is able to obtain an IP address. Which of the following is the MOST likely cause of this issue?

Accepted Answer

Duplex mismatch between the switch and the workstation. The rapidly alternating green and amber link LED on an unmanaged switch indicates a duplex mismatch or a high error rate on the link. Since the workstation can obtain an IP address, Layer 2 connectivity exists, but a duplex mismatch (e.g., the switch is set to auto-negotiate while the workstation is manually set to full duplex, or vice versa) causes excessive collisions or frame check sequence (FCS) errors, leading to retransmissions and slow speeds. This is the most likely cause because the LED behavior directly points to a physical-layer or data-link-layer negotiation problem.

Answer

Faulty patch cable connecting the workstation to the wall jack

Answer

IP address conflict with another device on the network

Answer

The switch is overheating due to poor ventilation

Question 2

A technician is setting up a small office network with a single internet connection from a cable modem. The office has two departments: Accounting and Sales. The technician needs to ensure that devices in Accounting cannot communicate with devices in Sales, but both departments must be able to access the internet. Which feature should the technician configure on the managed switch to meet this requirement?

Accepted Answer

Configure VLANs on the managed switch. VLANs (Virtual Local Area Networks) logically segment a switch into multiple isolated broadcast domains. By placing Accounting devices in one VLAN and Sales devices in another, the switch prevents Layer 2 communication between them, while both VLANs can still access the internet through a router configured with inter-VLAN routing or a separate uplink.

Answer

Enable DHCP on the router

Answer

Set up port forwarding on the router

Answer

Configure NAT on the router

Question 3

A technician is setting up a small network. The modem from the ISP provides a single public IP address via DHCP. The technician needs to connect 10 computers to the internet using a single public IP. Which device should the technician install between the modem and the computers to accomplish this?

Accepted Answer

Router with NAT capabilities. The modem provides a single public IP address via DHCP, but 10 computers need internet access. A router with NAT (Network Address Translation) allows multiple devices to share that single public IP by translating their private IP addresses (e.g., 192.168.1.x) to the public IP for outbound traffic, and mapping return traffic back to the correct internal device. This is the standard solution for IPv4 address conservation in small networks.

Answer

Hub

Answer

Switch

Answer

Bridge

Question 4

A technician installs a new VoIP desk phone for a user. The phone is connected to an existing wall jack using a Cat5e patch cable. The switch port on the other end shows a solid link light, but the phone does not power on. The technician verifies that the wall jack is wired correctly and the cable passes a continuity test. Which of the following is the MOST likely reason the phone is not receiving power?

Accepted Answer

The network switch does not support Power over Ethernet (PoE). The phone is not powering on despite a solid link light and a correctly wired, continuity-tested cable. This indicates the switch is providing a data link but not delivering power. The most likely cause is that the network switch does not support Power over Ethernet (PoE), which is required to supply DC power over the same Cat5e cable to the VoIP phone.

Answer

The switch port is administratively disabled

Answer

The patch cable is a crossover cable

Answer

The wall jack is wired with T568A instead of T568B

Question 5

A network technician is configuring a small office network. The office has two departments: Sales and Accounting. The technician needs to ensure that devices in Sales cannot communicate with devices in Accounting, but both departments must be able to access the internet. The network uses a single router and one managed switch. Which of the following should the technician configure on the switch?

Accepted Answer

VLANs. VLANs (Virtual Local Area Networks) allow the technician to logically segment the switch into separate broadcast domains. By placing Sales devices in one VLAN and Accounting devices in another, inter-VLAN communication is blocked at Layer 2, while both VLANs can still access the internet through the single router (which performs inter-VLAN routing if configured, but here only internet access is needed, so the router can simply provide default gateway connectivity without routing between VLANs).

Answer

Port mirroring

Answer

Link aggregation

Answer

Spanning Tree Protocol

Question 6

A technician is troubleshooting a small office network where users are reporting slow internet speeds. The network consists of a router connected to an unmanaged switch, and several workstations and printers connected to the switch. The technician notices that the cable connecting the router to the switch is a crossover cable. Both the router and the switch support Auto-MDI/X. Which of the following BEST describes the impact of using a crossover cable in this scenario?

Accepted Answer

The crossover cable is not causing the issue; Auto-MDI/X will handle the connection properly. Option C is correct because both the router and the switch support Auto-MDI/X (Automatic Medium-Dependent Interface Crossover), which allows them to automatically detect and correct the signal pairing for either a straight-through or crossover cable. Therefore, the crossover cable does not cause connectivity or speed issues; the slow internet problem must be investigated elsewhere (e.g., bandwidth saturation, duplex mismatch, or faulty hardware).

Answer

The crossover cable will prevent the devices from communicating because crossover cables are only used for connecting two similar devices directly

Answer

The crossover cable is faulty and should be replaced with a straight-through cable

Answer

The crossover cable should be replaced with a straight-through cable to achieve maximum throughput

Question 7

A network technician is troubleshooting a new fiber optic link between two buildings. The link is down. The technician uses a visual fault locator (VFL) at the transmitting end and observes a faint red glow at the patch panel in the receiving building. What does this indicate?

Accepted Answer

The fiber has a break or severe bend. A faint red glow from a visual fault locator (VFL) at the far-end patch panel indicates that the visible laser light is leaking through a break or severe bend in the fiber. VFLs inject a high-power visible red laser (typically 650 nm) into the core; if the fiber is intact, the light should be contained and invisible at the far end. A faint glow means the light is escaping from a damaged point, confirming a physical fault that prevents proper data transmission.

Answer

The fiber connectors are dirty

Answer

The transmitter power is too low

Answer

The connectors are mismatched (e.g., SC vs. LC)

Question 8

A network technician is configuring a small office network. The company wants to ensure that only authorized company devices can connect to the wired network. The network uses a managed switch and a DHCP server. Which security feature should the technician configure on the switch to BEST meet this requirement?

Accepted Answer

802.1X. 802.1X is the correct answer because it provides port-based network access control (PNAC) that authenticates devices before granting access to the wired network. It uses the Extensible Authentication Protocol (EAP) over LAN (EAPoL) to verify credentials against an authentication server (e.g., RADIUS), ensuring only authorized company devices can connect. This meets the requirement precisely by enforcing per-device authentication at the switch port level.

Answer

Port security

Answer

DHCP snooping

Answer

MAC address filtering

Question 9

A user reports that they can access internal network resources by IP address but cannot browse the internet by domain name (e.g., www.google.com). The technician checks the workstation's network adapter settings and sees that the IP address is obtained via DHCP. Which of the following is the MOST likely cause of this issue?

Accepted Answer

DNS server configuration. The user can access internal resources by IP address but not by domain name, which indicates that name resolution is failing. Since the workstation obtains its IP address via DHCP, the DNS server configuration is likely missing or incorrect, preventing the system from translating domain names like www.google.com into IP addresses.

Answer

Incorrect subnet mask

Answer

Wrong default gateway

Answer

Duplicate IP address

Question 10

A small office network uses a single router connected to a managed switch. The technician has configured two VLANs on the switch: VLAN 10 for Sales and VLAN 20 for Engineering. Both VLANs can access the internet, but devices in Sales cannot reach devices in Engineering. The router has one physical interface connected to the switch. The technician configured a subinterface on the router for each VLAN with appropriate IP addresses. However, devices on VLAN 20 cannot access the internet, while VLAN 10 works fine. Which of the following is the MOST likely missing configuration?

Accepted Answer

The switch port connecting to the router is not configured as a trunk port. The router uses subinterfaces for VLAN routing, which requires the switch port connecting to the router to be configured as a trunk port (802.1Q trunking). Without trunking, the switch port will only carry traffic from a single VLAN (likely VLAN 1 or the native VLAN), so VLAN 20 frames are dropped at the switch-to-router link. This explains why VLAN 10 works (if it matches the access VLAN on that port) and VLAN 20 fails to reach the internet.

Answer

The router's DHCP server is not configured for VLAN 20

Answer

The firewall on the router is blocking all traffic from VLAN 20

Answer

The VLAN 20 subinterface is not assigned a gateway IP address

Question 11

A small office uses a router with a built-in switch and a separate wireless access point. Users on the wired network can access the internet and internal resources, but wireless users cannot access any internal resources. Wireless users can connect to the access point and obtain an IP address in the 192.168.2.0/24 range, while wired users are on 192.168.1.0/24. The router's LAN interface is 192.168.1.1/24, and the access point is connected to the router's switch port and has an IP of 192.168.1.100/24. Which of the following is the MOST likely cause?

Accepted Answer

The router does not have a route between the two subnets.. The router's LAN interface is on 192.168.1.0/24, and the access point is connected to that same subnet with IP 192.168.1.100/24. Wireless clients receive IPs in 192.168.2.0/24, which is a different subnet. For traffic from 192.168.2.0/24 to reach internal resources on 192.168.1.0/24, the router must have a route between these two subnets. Without that route, the router drops or fails to forward packets, isolating wireless users from internal resources.

Answer

The access point is not configured as a bridge.

Answer

The wireless network encryption is set incorrectly.

Answer

The access point's DHCP server is conflicting with the router.

Question 12

A network technician is setting up a wireless access point (AP) for a small business. The company's router provides DHCP for the 192.168.1.0/24 network. The AP needs to broadcast two SSIDs: one for employees and one for guest users. The guest network must be completely isolated from the employee network and internal resources, while both SSIDs must have internet access. The AP is connected to a managed switch. Which configuration will BEST meet these requirements?

Accepted Answer

Configure VLANs on the managed switch and set the AP to tag the employee SSID on VLAN 10 and the guest SSID on VLAN 20; configure trunk port on switch to the AP. Option B is correct because it uses VLANs to logically separate the employee and guest traffic at Layer 2. By configuring the managed switch port as a trunk with VLAN 10 (employee) and VLAN 20 (guest), and having the AP tag each SSID to its respective VLAN, the guest network is isolated from the employee network and internal resources. The router can then route both VLANs to the internet via separate subinterfaces or a Layer 3 switch, ensuring both SSIDs have internet access while maintaining isolation.

Answer

Place both SSIDs on the same subnet and enable client isolation on the AP

Answer

Configure a DHCP reservation on the router for the AP and set the guest SSID to use a static IP in a different subnet

Answer

Disable the guest network's ability to access the default gateway by changing the AP's management settings

Question 13

A network technician is configuring a small office network with one router and one managed switch. The network has two VLANs: VLAN 10 (Sales) and VLAN 20 (Engineering). Both VLANs need internet access, and inter-VLAN routing is not required. The technician configures the router's single physical interface with IP 192.168.1.1/24 and creates subinterfaces for VLAN 10 (192.168.10.1/24) and VLAN 20 (192.168.20.1/24). The switch port connecting to the router is configured as an access port in VLAN 10. Which of the following is the MOST likely result?

Accepted Answer

Only VLAN 10 can access the internet; VLAN 20 cannot.. The router's subinterfaces for VLAN 10 and VLAN 20 are configured correctly, but the switch port connecting to the router is set as an access port in VLAN 10. An access port carries traffic for only one VLAN and strips VLAN tags, so the router's subinterface for VLAN 20 never receives or sends frames tagged for VLAN 20. Consequently, only VLAN 10 can reach the router's default gateway (192.168.10.1) and access the internet, while VLAN 20 has no path to the router.

Answer

Both VLANs can access the internet.

Answer

Only VLAN 20 can access the internet; VLAN 10 cannot.

Answer

Neither VLAN can access the internet.

Question 14

A network technician is configuring a router-on-a-stick for inter-VLAN routing. The router has one physical interface (G0/0) connected to a managed switch. The technician creates subinterfaces G0/0.10 for VLAN 10 (192.168.10.1/24) and G0/0.20 for VLAN 20 (192.168.20.1/24). The switch port connected to the router is configured as a trunk allowing VLANs 10 and 20. On a workstation in VLAN 10, the technician can ping the gateway 192.168.10.1 but cannot ping the gateway 192.168.20.1. Which of the following is the MOST likely cause?

Accepted Answer

The subinterface G0/0.20 is missing the encapsulation dot1Q 20 command. The workstation in VLAN 10 can ping its own gateway (192.168.10.1) but not the gateway in VLAN 20 (192.168.20.1). This indicates that the router's subinterface for VLAN 20 is not properly configured to accept and forward traffic from VLAN 20. The most likely cause is that the subinterface G0/0.20 is missing the `encapsulation dot1Q 20` command, which is required to tag frames with VLAN 20 ID when they traverse the trunk link. Without this command, the router will not process traffic for VLAN 20, and the gateway remains unreachable.

Answer

The switch trunk port is set to the wrong native VLAN

Answer

The workstation in VLAN 10 has an incorrect subnet mask

Answer

The router interface G0/0 is in a VLAN that is not allowed on the trunk

Question 15

A small office recently installed 12 new VoIP phones. Each phone is connected via an Ethernet cable to a 24-port managed PoE+ switch. The switch is powered on, and the network cables are properly terminated. However, none of the VoIP phones power on. The switch's power LED is solid, but the port LEDs remain off. Which of the following is the MOST likely cause?

Accepted Answer

The switch's PoE power budget has been exceeded. The switch's power LED is solid, indicating it has power, but the port LEDs are off, meaning no devices are being powered. Since all 12 VoIP phones are connected to a 24-port PoE+ switch, the most likely cause is that the total power draw of 12 phones exceeds the switch's PoE power budget. PoE+ (802.3at) provides up to 30W per port, but the switch has a limited total power supply (e.g., 250W), and 12 phones at 15-30W each could easily exceed that budget, causing the switch to deny power to all ports.

Answer

The switch ports are configured as access ports for a specific VLAN

Answer

The Ethernet cables are only Category 5 (Cat5)

Answer

The phones require a higher voltage than PoE+ provides