220-1101 Networking Practice Test 12 — 15 Questions

Question 1

A network technician is configuring a small office network with one router and one managed switch. The switch has two VLANs: VLAN 10 for Sales and VLAN 20 for Engineering. Both VLANs need internet access. The technician configures the router's single physical interface (G0/0) with 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 an access port in VLAN 10. Which of the following is the MOST likely result of this configuration?

Accepted Answer

Only devices in VLAN 10 can access the internet.. The switch port connected to the router is configured as an access port in VLAN 10. This means it only carries traffic for VLAN 10, stripping any VLAN tags. The router's subinterface G0/0.20 for VLAN 20 never receives or sends traffic because the access port does not allow VLAN 20 frames. Therefore, only devices in VLAN 10 can reach the router's default gateway (192.168.10.1) and access the internet.

Answer

Both VLAN 10 and VLAN 20 can access the internet.

Answer

Only devices in VLAN 20 can access the internet.

Answer

Neither VLAN can access the internet.

Question 2

A network technician is installing a new fiber optic link between two switches located in different buildings. The technician uses identical SFP modules on both ends and connects them with a single fiber patch cable. After powering on, the link lights on both switches remain off. The technician verifies the SFP modules are compatible with the switches and that the cable is not damaged. Which of the following should the technician check NEXT?

Accepted Answer

Swap the transmit and receive connections at one end of the fiber cable. The correct answer is A because fiber optic communication requires two separate strands: one for transmitting (TX) and one for receiving (RX). If a single fiber patch cable is used, it typically contains two fibers, but the connectors must be crossed at one end so that the TX of one switch connects to the RX of the other. Since the link lights are off despite compatible SFPs and an undamaged cable, the most likely issue is a polarity mismatch, where both ends are wired straight through (TX to TX, RX to RX), preventing the optical signal from being received.

Answer

Change the duplex settings on both switches to half-duplex

Answer

Update the firmware on both switches

Answer

Verify that the VLAN configuration matches on both ends

Question 3

A small business has a 24-port PoE+ switch powering 12 IP cameras (each requiring 15W) and 8 VoIP phones (each requiring 6W). The switch has a PoE budget of 240W. A technician installs two additional IP cameras (each 15W) but they do not power on. The existing cameras and phones continue to work normally. The technician has verified the Ethernet cables are good and the ports are enabled. Which of the following is the MOST likely cause?

Accepted Answer

The switch's PoE budget is exceeded by the additional cameras.. The switch has a PoE budget of 240W. The existing load is 12 cameras × 15W + 8 phones × 6W = 180W + 48W = 228W. Adding two more 15W cameras would require an additional 30W, totaling 258W, which exceeds the 240W budget. PoE switches use a power management algorithm to prioritize existing powered devices (PDs) and deny power to new ones when the budget is exceeded, which explains why the existing devices continue working while the new cameras do not power on.

Answer

The new cameras are connected with crossover cables instead of straight-through cables.

Answer

The new cameras are on a different VLAN that is not configured on the switch.

Answer

The DHCP server has run out of IP addresses in the scope.

Question 4

A network technician configures a managed switch with two VLANs: VLAN 10 (Marketing: 192.168.10.0/24) and VLAN 20 (Engineering: 192.168.20.0/24). The switch is connected to a router via a single trunk port. The router has subinterfaces configured: G0/0.10 with IP 192.168.10.1/24 and G0/0.20 with IP 192.168.20.1/24. A workstation in Marketing can ping its own default gateway (192.168.10.1) but cannot ping the Engineering gateway (192.168.20.1). Which of the following is the MOST likely cause?

Accepted Answer

The switch port connecting to the router is configured as an access port in VLAN 10. The workstation in Marketing can ping its own gateway (192.168.10.1) because that subnet is directly reachable via the switch. However, it cannot ping the Engineering gateway (192.168.20.1) because the switch port connecting to the router is configured as an access port in VLAN 10. This forces all traffic from the router to the switch to be untagged and only in VLAN 10, so frames destined for VLAN 20 are dropped or misdelivered. A trunk port with 802.1Q encapsulation is required to carry both VLANs over the single link.

Answer

The router's subinterface G0/0.20 is not configured with the correct encapsulation

Answer

The workstation in Marketing has an incorrect subnet mask

Answer

The routing table on the router does not have routes for the Engineering subnet

Question 5

A small office recently installed eight 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 for the connected phones remain off. The technician verifies that the PoE budget of the switch (240W) is sufficient for all eight phones (each requiring 6.5W). Which of the following is the MOST likely cause?

Accepted Answer

PoE is disabled on the switch ports or globally.. The most likely cause is that PoE is disabled on the switch ports or globally. Even though the switch supports PoE+ and has sufficient power budget, PoE must be explicitly enabled per port or globally via commands like 'power inline auto' or 'power inline never'. The solid power LED indicates the switch is powered, but the off port LEDs show no power is being delivered to the phones, which is consistent with PoE being administratively disabled.

Answer

The Ethernet cables are not PoE-compatible.

Answer

The VLAN configuration on the switch is preventing the phones from receiving power.

Answer

The switch's power supply cannot supply enough total wattage.

Question 6

A technician is troubleshooting a workstation that cannot connect to the network. The link light on the network interface card is blinking amber, and the switch port shows no link light. The Ethernet cable run from the workstation to the patch panel is approximately 125 meters. Which of the following is the MOST likely cause of the connectivity issue?

Accepted Answer

The cable exceeds the maximum segment length for Ethernet.. The Ethernet cable run is 125 meters, which exceeds the IEEE 802.3 maximum segment length of 100 meters for twisted-pair copper cabling (e.g., Cat5e, Cat6). This distance causes signal attenuation and timing issues, preventing the switch port from establishing a link, as indicated by the absence of a link light on the switch and the amber blinking link light on the NIC (which often signals a physical-layer problem).

Answer

The cable is damaged near the connector.

Answer

The network switch is not providing PoE.

Answer

The workstation's NIC is set to a static IP address.

Question 7

A network technician is troubleshooting intermittent connectivity issues on a small office network. The issue only occurs for a few minutes at a time, and users lose access to both internal servers and the internet. During the issue, the technician can ping the default gateway from the core switch but not from the router. The router logs show multiple 'Duplicate IP address' errors for the router's LAN interface. Which of the following is the MOST likely cause?

Accepted Answer

A rogue DHCP server on the network. The 'Duplicate IP address' error on the router's LAN interface indicates that another device on the network is using the same IP address as the router. A rogue DHCP server can assign the router's IP address to another client, causing intermittent connectivity loss. During the conflict, the router cannot respond to traffic, which explains why pinging the default gateway fails from the router but succeeds from the core switch (which may have a cached ARP entry or be on a different VLAN).

Answer

A misconfigured DHCP server on the network

Answer

A spanning tree protocol convergence loop

Answer

A faulty network cable causing CRC errors

Question 8

A user reports that they cannot access any websites through their web browser, but they can access shared files on the local network and can successfully ping 8.8.8.8 from the command prompt. The technician checks the IP configuration and finds the workstation has a valid IP address, subnet mask, and default gateway. The DNS server is set to 8.8.8.8. Which of the following is the MOST likely cause of the issue?

Accepted Answer

The web browser proxy settings are configured incorrectly, preventing internet access. The user can ping 8.8.8.8 (a public IP) and access local network shares, confirming that IP connectivity and DNS resolution to that specific server are working. However, they cannot browse websites, which typically use hostnames. Since the DNS server is set to 8.8.8.8 and pinging that IP succeeds, the issue is not DNS resolution itself but rather the web browser not using the correct network path. Incorrect proxy settings in the browser can cause it to send requests to a proxy server that is unreachable or misconfigured, effectively blocking internet access while other applications function normally.

Answer

A firewall rule is blocking all outbound traffic on ports 80 and 443

Answer

The DNS suffix search order is misconfigured

Answer

The ARP cache is corrupted, preventing the workstation from communicating with the default gateway

Question 9

A technician connects a workstation to a switch port configured for VLAN 30. The network uses DHCP servers located on VLAN 10. After connecting, the workstation receives an APIPA address (169.254.x.x). The technician verifies that the Ethernet cable is functional and the switch port link light is solid. Other workstations on the same switch, connected to ports in VLAN 10, obtain valid IP addresses. Which of the following is the MOST likely cause of the issue?

Accepted Answer

The workstation is not receiving a DHCP offer because it is on a different VLAN than the DHCP server. The workstation is on VLAN 30, but the DHCP server resides on VLAN 10. By default, DHCP broadcasts (using UDP port 67/68) are not forwarded across VLANs unless a DHCP relay agent (IP helper-address) is configured on the VLAN 30 interface. Without that relay, the workstation never receives a DHCP offer, so it falls back to an APIPA address (169.254.x.x per RFC 3927).

Answer

The switch port is configured as a trunk port

Answer

The network cable is faulty

Answer

The workstation's NIC driver is outdated

Question 10

A technician configures a new workstation on a managed switch port. The workstation successfully obtains an IP address from the DHCP server and can ping its own IP address as well as the default gateway. However, it cannot ping any other workstations on the same subnet. The technician has verified that the Ethernet cable is good and the switch port link is up. Which of the following should the technician check NEXT?

Accepted Answer

The VLAN assignment on the switch port. The workstation can obtain an IP address and ping the default gateway, indicating Layer 3 connectivity to the local subnet is functional. The inability to ping other workstations on the same subnet suggests a Layer 2 isolation issue, most commonly caused by the switch port being assigned to a different VLAN than the other workstations. VLANs segment broadcast domains, so devices in different VLANs cannot communicate directly without a router, even if they share the same IP subnet.

Answer

The DNS server settings

Answer

The workstation's subnet mask

Answer

The speed and duplex settings on the switch port

Question 11

A user reports that their laptop cannot access the internet but can still access shared files on the local network. The technician runs ipconfig and sees an IP address of 169.254.15.32. Which of the following is the MOST likely cause of this issue?

Accepted Answer

The DHCP server is unavailable. The IP address 169.254.15.32 is an Automatic Private IP Addressing (APIPA) address, which Windows assigns when a DHCP server is unavailable and the client fails to obtain a lease. Since the laptop can still access local shared files, the local network is functional, but without a valid DHCP-assigned IP, it cannot reach external networks or the internet. This directly points to the DHCP server being unavailable.

Answer

The DNS server is not responding

Answer

The default gateway is misconfigured

Answer

The subnet mask is incorrect

Question 12

A technician connects a new workstation to a switch port that is configured with port security and a maximum of one MAC address. After connecting the workstation, the port link LED remains off. The technician has verified the Ethernet cable is good, the switchport is not administratively down, and the workstation's NIC is functioning. Which of the following is the MOST likely cause?

Accepted Answer

The workstation's MAC address violates port security, causing the port to error-disable. Port security with a maximum of one MAC address will place the port into an error-disabled state if a MAC address violation occurs, such as when the workstation's MAC address differs from the one already learned or when the port detects a new MAC after the limit is reached. The link LED being off indicates the port is administratively up but not operational, which is consistent with an error-disabled condition caused by a security violation. Since the cable, switchport status, and NIC are verified good, the most likely cause is that the workstation's MAC triggered a port security violation, disabling the port.

Answer

The switchport is configured for a different VLAN than the workstation

Answer

The switch requires a reboot to recognize the new workstation

Answer

The workstation has a duplicate IP address on the network

Question 13

A small office network uses an unmanaged switch to connect 20 workstations to a router. After connecting the 11th workstation, all previously connected workstations begin losing internet connectivity intermittently. The switch link lights remain solid green for all connected devices. The technician discovers that the new workstation has two active network interfaces, both plugged into the same switch. Which of the following is the MOST likely cause?

Accepted Answer

Network loop. The new workstation has two active network interfaces both plugged into the same unmanaged switch, creating a physical network loop. This loop causes broadcast storms and MAC address table instability (the switch repeatedly learns the same MAC address on different ports), which overwhelms the switch and causes intermittent connectivity for all devices. Unmanaged switches lack Spanning Tree Protocol (STP) to detect and block redundant paths, so the loop is not automatically resolved.

Answer

IP address conflict

Answer

Switch is faulty

Answer

Exceeded DHCP scope

Question 14

A network technician connects two switches together using a straight-through Cat6 Ethernet cable. Both switches are managed and are known to be working. After connecting, the link LED on Switch A is off, and the link LED on Switch B is also off. The technician has verified that both switch ports are enabled and not administratively shut down. Which of the following is the MOST likely cause of the problem?

Accepted Answer

At least one switch does not support auto-MDIX.. When two switches are connected directly, auto-MDIX (Automatic Medium-Dependent Interface Crossover) allows either a straight-through or crossover cable to be used by automatically negotiating the transmit/receive pairs. If at least one switch does not support auto-MDIX, a straight-through cable will not work because the transmit pins on one switch will connect to transmit pins on the other, causing a link failure. Since both link LEDs are off and the ports are enabled, the most likely cause is that one or both switches lack auto-MDIX support, requiring a crossover cable instead.

Answer

The cable is a crossover cable.

Answer

The cable length exceeds 100 meters.

Answer

One of the switches has the wrong VLAN assignment.

Question 15

A user reports that their laptop cannot detect any wireless networks. The technician sees that the Wi-Fi adapter is enabled in the device manager and has no errors. The laptop has a physical wireless switch on the front edge and a function key (Fn) combination to toggle Wi-Fi. Which of the following should the technician check FIRST?

Accepted Answer

Whether the physical wireless switch is in the ON position. The physical wireless switch is a hardware-level cutoff that can completely disable the Wi-Fi radio, regardless of driver or software settings. Since the adapter shows as enabled in Device Manager with no errors, the most likely cause is that the switch is in the OFF position, which prevents the radio from scanning for networks. Checking this is the fastest and simplest first step before moving to software or driver troubleshooting.

Answer

Whether the network driver needs to be updated

Answer

Whether the Windows Firewall is blocking network discovery

Answer

Whether the antenna cables are connected to the wireless card