220-1101 Networking Practice Test 8 — 15 Questions

Question 1

A technician is troubleshooting a workstation that is connected to a managed switch. The link lights on both the workstation and switch are illuminated, but the workstation cannot obtain an IP address from the DHCP server. The technician manually configures a static IP address (192.168.1.100, subnet mask 255.255.255.0, default gateway 192.168.1.1) on the workstation, but it still cannot ping the router (192.168.1.1). Other workstations on the same switch can ping the router successfully. Which of the following is the MOST likely cause of this issue?

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

Accepted Answer

Speed/duplex mismatch between the switch port and the workstation NIC. The link lights are on, indicating Layer 1 connectivity, but the inability to obtain a DHCP lease or ping the gateway despite a correct static IP suggests a Layer 2 issue. A speed/duplex mismatch causes excessive frame errors and collisions, effectively breaking communication even though the physical link appears active. This is the most likely cause because other workstations on the same switch work fine, isolating the problem to the specific switch port or workstation NIC configuration.

Answer

Duplicate IP address on the network

Answer

Incorrect subnet mask

Answer

Damaged Ethernet cable

Question 2

A technician sets up a small office network. The router is configured with DHCP providing addresses in the 192.168.1.0/24 range. A new employee's laptop obtains an IP address of 192.168.1.50, subnet mask 255.255.255.0, and default gateway 192.168.1.1. The laptop can ping other local workstations and the router (192.168.1.1), but cannot access any external websites by domain name or IP address. Which of the following is the MOST likely cause of this issue?

Accepted Answer

The router's WAN connection is not properly configured or is down.. The laptop can ping the local router (192.168.1.1) and other local workstations, which confirms that the laptop's IP configuration (address, subnet mask, default gateway) is correct and that the local LAN is functioning. However, the inability to reach any external websites by either domain name or IP address indicates that the router cannot forward traffic beyond its local subnet. The most likely cause is that the router's WAN connection is not properly configured or is down, preventing any outbound traffic from reaching the internet.

Answer

The laptop's DNS server configuration is incorrect.

Answer

The default gateway is not set correctly on the laptop.

Answer

A firewall on the router is blocking all outbound traffic from the laptop.

Question 3

A technician connects a new workstation to a wall jack in an office. The link lights on both the workstation's NIC and the switch port are solid green. The workstation cannot obtain an IP address via DHCP. The technician manually assigns a static IP address in the same subnet as other working workstations (192.168.1.100/24, gateway 192.168.1.1), but the workstation still cannot ping the gateway or any other device on the network. Other workstations connected to the same switch can access network resources normally. Which of the following is the MOST likely cause of this issue?

Accepted Answer

The switch port has port security enabled, and the workstation's MAC address is not allowed. The solid link lights indicate Layer 1 connectivity is good, ruling out a faulty cable. The inability to obtain an IP via DHCP and the failure to ping the gateway even with a manually assigned static IP in the correct subnet point to a Layer 2 filtering mechanism. Port security on the switch port is the most likely cause, as it would block all traffic from an unauthorized MAC address, preventing DHCP discovery and any subsequent communication, even with a valid static IP.

Answer

The IP address 192.168.1.100 is already in use by another device

Answer

The Ethernet cable is faulty

Answer

The DHCP server has exhausted its IP address pool

Question 4

A company uses a managed PoE switch to power IP phones. A new IP phone is connected to a wall jack that is patched to the switch. The switch port shows 'not powered' in the management interface, even though PoE is enabled globally and the phone is known to work. Which of the following is the MOST likely cause?

Accepted Answer

The PoE power budget for the switch has been exceeded. The most likely cause is that the PoE power budget for the switch has been exceeded. Even though PoE is enabled globally, the switch can only supply a finite amount of total power (e.g., 370W for a Cisco 3750X). If the cumulative power draw of all connected devices surpasses this budget, the switch will deny power to new devices, showing the port as 'not powered' while the phone itself is known to work.

Answer

The patch cable is a crossover cable

Answer

The IP phone requires a higher PoE standard than the switch supports

Answer

The port is administratively disabled

Question 5

A small office network uses a managed switch with port security enabled. A new employee connects their laptop to a configured port, but the laptop cannot obtain an IP address or communicate on the network. The link light on the switch port is on. Other ports in the same VLAN work correctly. Which of the following is the MOST likely cause?

Accepted Answer

The switch port has MAC address filtering enabled that does not include the laptop's MAC. Port security with MAC address filtering restricts which devices can communicate through a switch port based on their MAC address. Since the link light is on (Layer 1 is up) but the laptop cannot obtain an IP address or communicate, the switch is likely dropping frames from the laptop's MAC because it is not in the allowed MAC list. This prevents DHCP discovery and all other traffic, even though the physical connection is established.

Answer

The switch port is administratively shut down

Answer

The laptop has a static IP address that conflicts with another device

Answer

The switch port is not in the correct VLAN

Question 6

A workstation is connected to a managed switch. It obtains a valid IP address (192.168.10.50) from the DHCP server, but it cannot ping the default gateway (192.168.10.1). The link light on both the workstation NIC and the switch port are solid green. Other workstations on the same switch CAN ping the default gateway successfully. The technician accesses the switch management interface and finds that the workstation's port is configured as an access port on VLAN 10. The default gateway is located on VLAN 20. An inter-VLAN router is configured but not explicitly allowing VLAN 10 access to VLAN 20. Which of the following is the MOST likely cause of the problem?

Accepted Answer

The switch port is assigned to VLAN 10, while the default gateway exists on VLAN 20, preventing connectivity without proper inter-VLAN routing.. The workstation is on VLAN 10, but the default gateway is on VLAN 20. Without inter-VLAN routing explicitly allowing traffic between VLAN 10 and VLAN 20, the workstation cannot reach the gateway, even though it has a valid IP address from the correct subnet. The link lights are solid green, indicating Layer 1 connectivity is fine, and other workstations on the same switch can ping the gateway, confirming the switch and gateway are operational.

Answer

The workstation's IP address is from a different subnet than the default gateway.

Answer

The workstation's network interface card (NIC) is malfunctioning.

Answer

The DHCP server provided an incorrect default gateway address.

Question 7

A technician configured a workstation with a static IP address of 192.168.1.100, subnet mask 255.255.255.0, default gateway 192.168.1.1, and DNS server 8.8.8.8. The workstation can successfully ping the default gateway and other local devices on the same subnet. However, the user cannot browse any websites. The technician verifies that the internet connection is working from other devices on the network. Which of the following is the MOST likely reason the workstation cannot access websites?

Accepted Answer

The DNS server is unreachable, preventing domain name resolution.. The workstation can ping the default gateway and local devices, confirming that Layer 3 IP connectivity and the subnet mask are correct. However, it cannot browse websites, which requires DNS resolution to translate domain names into IP addresses. Since the DNS server 8.8.8.8 is unreachable (possibly blocked or not responding), the browser cannot resolve website names, even though internet connectivity exists for other devices.

Answer

The default gateway is incorrect.

Answer

The subnet mask is incorrect.

Answer

The workstation has a duplicate IP address.

Question 8

A user reports that their desktop computer loses network connectivity every few minutes, especially when the nearby overhead fluorescent lights are turned on. The technician observes that the link light on the NIC occasionally turns off during these events. The Ethernet cable is a Cat5e unshielded twisted pair (UTP) cable routed through the ceiling near the light fixtures. Which of the following is the MOST likely cause of the intermittent connectivity?

Accepted Answer

Electromagnetic interference (EMI) from the fluorescent lights is affecting the unshielded cable. Unshielded twisted pair (UTP) cables lack shielding against electromagnetic interference (EMI). Fluorescent lights, especially older magnetic-ballast fixtures, generate strong EMI that can induce noise in nearby UTP cables, corrupting data signals and causing the NIC's link light to drop. This explains the correlation between the lights turning on and the loss of connectivity.

Answer

The network interface card (NIC) is faulty and needs replacement

Answer

The switch port is configured with an incorrect VLAN assignment

Answer

The DHCP server has exhausted its IP address scope

Question 9

A user installs a new third-party security software suite on their Windows workstation. After installation, the user can still access files on the local network and can ping external IP addresses like 8.8.8.8, but cannot browse any websites using a web browser. Other workstations on the same network are unaffected. Which of the following is the MOST likely cause?

Accepted Answer

The security software's firewall is blocking outbound HTTP/HTTPS traffic. The user can ping external IP addresses (e.g., 8.8.8.8) and access local network files, which confirms that IP connectivity, the default gateway, and DNS resolution for local resources are working. However, the inability to browse websites (which use HTTP/HTTPS) while other workstations are unaffected strongly indicates that the new third-party security software's firewall is blocking outbound TCP ports 80 and 443. This is a common behavior of security suites that enable strict outbound filtering by default.

Answer

The DNS server address was changed by the software

Answer

The workstation's default gateway was removed

Answer

The security software corrupted the browser's configuration files

Question 10

A technician is configuring a small office network with a managed switch and a router that supports inter-VLAN routing. A workstation on VLAN 10 (192.168.10.0/24) can ping other workstations on VLAN 10 but cannot ping a server on VLAN 20 (192.168.20.0/24). The switch has a trunk port connecting to the router, and the trunk is configured to allow VLANs 10 and 20. The workstation's default gateway is set to 192.168.10.1. The server's default gateway is set to 192.168.20.1. Which of the following is the MOST likely cause of the problem?

Accepted Answer

A. The router's subinterface for VLAN 20 is not configured or is incorrectly configured.. The workstation can communicate within VLAN 10 but cannot reach VLAN 20, indicating that inter-VLAN routing is failing. Since the trunk is correctly allowing VLANs 10 and 20, the most likely cause is that the router's subinterface for VLAN 20 (e.g., GigabitEthernet0/0.20) is missing, has an incorrect encapsulation dot1Q 20 command, or lacks an IP address in the 192.168.20.0/24 subnet. Without a properly configured subinterface, the router cannot route traffic to or from VLAN 20.

Answer

B. The workstation's firewall is blocking ICMP echo requests.

Answer

C. The switch port connecting the router is configured as an access port on VLAN 1.

Answer

D. The server's default gateway is set to 192.168.20.254.

Question 11

A technician configures a new workstation with DHCP. Initially, the workstation obtains an IP address of 192.168.1.100/24 with default gateway 192.168.1.1 and can browse the internet. After approximately 30 minutes, the user reports that internet access stops working, but the workstation can still ping other local devices on the same subnet. The technician runs ipconfig and sees that the workstation now has an IP address of 169.254.15.78. Which of the following is the MOST likely cause?

Accepted Answer

The DHCP lease expired and the workstation could not contact the DHCP server to renew it. The workstation initially received a valid DHCP lease (192.168.1.100/24). After 30 minutes, the lease expired, and the workstation failed to renew it from the DHCP server. As a result, Windows Automatic Private IP Addressing (APIPA) assigned a 169.254.x.x address, which allows local subnet communication but not internet access. This matches the symptom of losing internet while retaining local connectivity.

Answer

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

Answer

The DNS server address provided by DHCP has become invalid

Answer

The switch port the workstation is connected to was moved to a different VLAN without trunking

Question 12

Employees in a small office report that their wired network connections become extremely slow or drop every time the office microwave oven is used. The microwave is located in the breakroom, and the network cables for the cubicles run through the ceiling directly above the breakroom. The cables currently installed are unshielded twisted pair (UTP) Cat5e. The technician has confirmed the microwave is not physically damaging the cables and that the router and switch are not overheating. Which of the following solutions would MOST effectively resolve the intermittent network issues?

Accepted Answer

Replace the UTP Cat5e cables with STP Cat6a cables. The intermittent network slowdowns and drops are caused by electromagnetic interference (EMI) generated by the microwave oven, which radiates strongly in the 2.4 GHz range. UTP Cat5e cables lack shielding and are susceptible to this EMI, especially when running through the ceiling directly above the microwave. Replacing them with STP Cat6a cables provides foil or braided shielding that blocks EMI, preserving signal integrity and resolving the issue.

Answer

Upgrade the network switches to models that support QoS (Quality of Service)

Answer

Install ferrite chokes on both ends of each network cable

Answer

Replace the RJ45 wall jacks with shielded Cat6 jacks

Question 13

A small office network uses a single router configured as a DHCP server for the 192.168.1.0/24 network. The DHCP scope is set to 192.168.1.10 - 192.168.1.50. Over the past week, several workstations have reported intermittent connectivity. The technician checks a workstation and finds that its IP address has changed from 192.168.1.20 to 169.254.15.100. Other workstations also show similar APIPA addresses. The DHCP server logs indicate that many lease requests are being declined. The network has 45 devices that require IP addresses. Which of the following is the MOST likely cause of the issue?

Accepted Answer

The DHCP scope is too small for the number of devices on the network. The DHCP scope is 192.168.1.10–192.168.1.50, which provides only 41 usable addresses. With 45 devices requiring IP addresses, the scope is exhausted. When a DHCP server cannot assign an address, clients self-assign an APIPA address (169.254.x.x) per RFC 3927, explaining the intermittent connectivity and declined lease requests.

Answer

The DHCP server is malfunctioning and needs to be restarted

Answer

The DNS server is not resolving hostnames correctly

Answer

The network switch is flooding the network with broadcast traffic

Question 14

A user can access local network resources but cannot browse the internet. Other users on the same network have no issues. The technician checks the workstation's IP configuration: IP 192.168.1.100, subnet mask 255.255.255.0, default gateway 192.168.1.1, DNS server 192.168.1.1. The workstation successfully pings the default gateway (192.168.1.1). The technician then tries to ping 8.8.8.8 and the ping fails. Which of the following should the technician check NEXT?

Accepted Answer

The routing table on the router. Since the workstation can ping the default gateway (192.168.1.1) but cannot ping 8.8.8.8, the issue is beyond the local subnet. This indicates a routing problem, not a local connectivity or DNS issue. The technician should check the router's routing table to ensure there is a default route (0.0.0.0/0) pointing to the ISP or upstream gateway, as the router may not be forwarding traffic to external networks.

Answer

The switch port configuration

Answer

The DNS server settings

Answer

The DHCP lease expiration

Question 15

A user reports that they cannot access the internet, but they can still access shared folders on the local network. The technician runs ipconfig on the workstation and sees an IP address of 169.254.10.15 with a subnet mask of 255.255.0.0. Which of the following is the MOST likely cause of this issue?

Accepted Answer

The DHCP server is unavailable. The IP address 169.254.10.15 with a subnet mask of 255.255.0.0 is an Automatic Private IP Addressing (APIPA) address, which Windows assigns when a DHCP server is unavailable or fails to respond. Since the user can still access local shared folders (local link-layer communication works), but cannot reach the internet, the core issue is the lack of a valid DHCP lease, not a DNS or gateway misconfiguration.

Answer

The DNS server is not responding

Answer

The default gateway address is incorrect

Answer

The workstation has a static IP address configured