220-1101 Networking Practice Test 13 — 15 Questions

Question 1

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?

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

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 2

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 3

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 4

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 5

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 6

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

Question 7

A technician installs a new PoE security camera in an office. The camera is connected to a wall jack that runs to a PoE-enabled switch. The camera does not power on. The technician tests the cable with a cable tester and it passes. The switch port has a solid link light. The technician connects a known-working laptop to the same wall jack, and the laptop gets an IP address and can access the network. Which of the following is the MOST likely cause of this issue?

Accepted Answer

The camera requires a higher PoE standard than the switch provides.. The camera does not power on despite the cable passing a continuity test, the switch port showing a link light, and a known-working laptop successfully obtaining an IP address through the same wall jack. This indicates that the physical layer and basic network connectivity are functional, but the PoE power delivery is insufficient. The most likely cause is that the camera requires a higher PoE standard (e.g., PoE+ 802.3at, which provides up to 30W) than the switch provides (e.g., standard PoE 802.3af, which provides up to 15.4W), so the camera cannot draw enough power to boot.

Answer

The cable is too long for PoE to function correctly.

Answer

The switch port does not have PoE enabled.

Answer

The camera has an IP address conflict with another device on the network.

Question 8

A technician is setting up a small office network with 15 computers, a router, and an unmanaged switch. The computers are configured with static IP addresses. After connecting all computers to the switch, the technician notices that some computers can communicate with each other but cannot access the internet. The router's LAN IP is 192.168.1.1 with subnet mask 255.255.255.0. The computers have IP addresses in the range 192.168.1.2-192.168.1.16 with default gateway 192.168.1.1. The technician pings the router from a computer that cannot access the internet, and the ping times out. Which of the following is the MOST likely cause?

Accepted Answer

The Ethernet cable connecting the switch to the router is faulty.. The ping from a computer to the router (192.168.1.1) times out, indicating that Layer 3 connectivity to the router is absent. Since the switch is unmanaged and operates at Layer 2, it does not perform VLAN routing or filtering; the most likely cause is a physical or data-link layer issue on the link between the switch and the router, such as a faulty Ethernet cable. A faulty cable would prevent frames from reaching the router, causing the ping timeout and the inability to access the internet.

Answer

The switch is not forwarding traffic to the router due to a VLAN mismatch.

Answer

The computers are configured with the wrong subnet mask.

Answer

The router's firewall is blocking ICMP traffic.

Question 9

A network administrator is setting up a new wireless network for a small business. The administrator configures a wireless access point with WPA2-PSK and a strong passphrase. Several users on different floors report intermittent connectivity and slow speeds. The administrator checks the access point and finds that the signal strength is excellent in the area. The access point is dual-band (2.4GHz and 5GHz) and broadcasts a single SSID. Which of the following is the MOST likely cause of the issue?

Accepted Answer

The channel width is set to 40MHz on the 2.4GHz band, causing interference.. In the 2.4 GHz band, using a 40 MHz channel width consumes more spectrum and overlaps with adjacent channels, causing co-channel and adjacent-channel interference. This interference leads to intermittent connectivity and slow speeds, especially on different floors where signal propagation is more complex. The strong signal strength and dual-band setup with a single SSID point to channel width misconfiguration as the most likely cause.

Answer

The access point is configured to use the default IP address, causing an IP conflict.

Answer

The encryption type is too weak for the number of users.

Answer

The access point's firmware is outdated and needs an update.

Question 10

A technician is configuring a small office network with a PoE-managed switch and several VoIP phones. All phones are connected and working except one. On the non-working phone, the Ethernet link light is solid on both the phone and the switch port, but the phone's display remains dark and it does not power on. The technician has verified the cable with a tester and it passes. The switch port is enabled and configured for the same VLAN as other working phones. Which of the following is the MOST likely cause?

Accepted Answer

The switch port's PoE power budget has been exceeded.. A PoE-managed switch allocates power from a finite budget. If the total power draw of all connected devices exceeds the switch's PoE power budget, the switch may deny power to additional devices even if the port is administratively enabled and the link is up. The solid Ethernet link light indicates Layer 1 connectivity, but the phone's dark display and lack of power suggest it is not receiving PoE, which is consistent with the switch having exhausted its PoE budget.

Answer

The phone's MAC address is incorrect.

Answer

The cable is a crossover cable.

Answer

The switch port is in a different subnet.

Question 11

A network technician configures a managed switch with two VLANs: VLAN 10 for workstations and VLAN 20 for servers. A workstation on VLAN 10 can ping its default gateway (192.168.10.1), and a server on VLAN 20 can ping its default gateway (192.168.20.1). However, the workstation cannot ping the server's IP address (192.168.20.10). All switch ports are configured as access ports in their respective VLANs, and the default gateways are correctly assigned. Which of the following is MOST likely needed to allow this communication?

Accepted Answer

A router configured for inter-VLAN routing. The workstation and server are on different VLANs, which are separate Layer 2 broadcast domains. Even though each device can reach its own default gateway, communication between VLANs requires a Layer 3 device to route packets between them. A router configured for inter-VLAN routing (either router-on-a-stick or a Layer 3 switch) is necessary to forward traffic from VLAN 10 to VLAN 20.

Answer

A DHCP server on each VLAN

Answer

A higher category Ethernet cable

Answer

A trunk port between the switch and the router

Question 12

A technician is troubleshooting a workstation that can access internal network resources and the internet, but users report that they cannot browse websites using domain names (e.g., www.example.com). The technician opens a command prompt and successfully pings a public IP address (8.8.8.8), but pinging www.google.com returns 'Ping request could not find host'. The workstation receives IP settings via DHCP. Which of the following is the MOST likely cause?

Accepted Answer

The DNS server addresses are not being provided by DHCP. The workstation can ping a public IP address (8.8.8.8) but cannot resolve domain names like www.google.com. This indicates that IP connectivity is working, but DNS resolution is failing. Since the workstation receives IP settings via DHCP, the most likely cause is that the DHCP server is not providing correct DNS server addresses, leaving the workstation without a valid DNS resolver.

Answer

The default gateway is misconfigured

Answer

The workstation's firewall is blocking DNS traffic

Answer

The router's NAT is misconfigured

Question 13

A user reports that their workstation cannot access the internet. The technician runs ipconfig and sees that the workstation has an IP address of 169.254.23.45 with a subnet mask of 255.255.0.0. The technician checks the network cable and link lights; they are normal. Which of the following is the MOST likely cause?

Accepted Answer

The DHCP server is not responding. The IP address 169.254.23.45 with a subnet mask of 255.255.0.0 is an Automatic Private IP Addressing (APIPA) address, which Windows assigns when a DHCP server cannot be reached. Since the link lights are normal and the cable is not faulty, the most likely cause is that the DHCP server is not responding, preventing the workstation from obtaining a valid IP address.

Answer

The Ethernet cable is faulty

Answer

The DNS server is misconfigured

Answer

The default gateway is incorrect

Question 14

A user reports that their workstation can access local network shares and printers but cannot access the internet. The technician pings the default gateway (192.168.1.1) successfully. The technician pings a public DNS server (8.8.8.8) and the request times out. Which of the following is the MOST likely cause?

Accepted Answer

The router's WAN connection is not functioning. The technician can ping the default gateway (192.168.1.1) successfully, confirming that the workstation's local IP configuration and Layer 2/3 connectivity to the router are correct. However, pinging the public DNS server 8.8.8.8 times out, which indicates that traffic is reaching the router but cannot exit to the internet. This points to a failure in the router's WAN connection (e.g., the modem or ISP link), as the router itself is reachable but cannot forward packets beyond the local subnet.

Answer

Incorrect DNS server configured on the workstation

Answer

The workstation's default gateway is misconfigured

Answer

The workstation's subnet mask is incorrect

Question 15

A technician connects a new workstation to a managed switch port that is configured with PortFast and BPDU guard. The workstation obtains an IP address via DHCP and can ping its own IP address, but it cannot ping any other devices on the local network, including the default gateway. The link light on both the NIC and switch port is solid green. On the switch, the port status shows 'errdisable' with the reason 'BPDU guard'. Which of the following is the MOST likely cause of this issue?

Accepted Answer

The workstation's NIC is running Spanning Tree Protocol, which the switch's BPDU guard detected and shut down the port.. BPDU guard is a security feature that disables a PortFast-enabled port if it receives any Bridge Protocol Data Unit (BPDU). A workstation NIC should never send BPDUs, but some NICs or their drivers (e.g., when teaming or virtualization software is active) may inadvertently run Spanning Tree Protocol (STP) and generate BPDUs. When the switch receives a BPDU on a BPDU guard-protected port, it immediately places the port into errdisable state, blocking all traffic except the link light remains solid. This explains why the workstation can obtain an IP (DHCP traffic occurred before the port was disabled) but cannot ping any other devices after the port is errdisabled.

Answer

The workstation's firewall is blocking traffic.

Answer

The switch port is configured as an access port in the wrong VLAN.

Answer

The workstation's NIC has a static IP address that conflicts with another device.