220-1101 Networking Practice Test 4 — 15 Questions

Question 1

A technician is setting up a small network with a router, a 24-port unmanaged switch, and 15 computers. The router's DHCP server assigns IP addresses in the 192.168.1.0/24 range. All computers get valid IP addresses and can access the internet, but they cannot see each other in the network discovery list. Which of the following is the MOST likely cause?

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

Accepted Answer

Network discovery and file sharing are disabled on the computers. The computers can access the internet and receive valid IP addresses from the router's DHCP server, indicating that Layer 3 connectivity is working. However, they cannot see each other in the network discovery list, which is a Layer 2/application-layer feature. Network discovery relies on the Function Discovery Resource Publication (FDResPub) and SSDP protocols, and file sharing relies on the SMB protocol; both are typically disabled by default on Windows machines for security reasons. Enabling network discovery and file sharing in the Network and Sharing Center resolves the visibility issue.

Answer

The switch is not configured with VLANs

Answer

The subnet mask is set to 255.255.0.0

Answer

The router's firewall is blocking LAN traffic

Question 2

An ISP provides a cable modem with a single Ethernet port. A technician needs to set up a small office network with 25 workstations that require internet access and must be on the same subnet. The technician has a 24-port unmanaged switch and a 48-port unmanaged switch. Which of the following is the MOST appropriate method to connect the devices?

Accepted Answer

Connect both switches to a router, and connect the modem to the router.. A router is required to perform Network Address Translation (NAT) and routing between the ISP's public IP and the private subnet. The cable modem provides only a single Ethernet port and does not route traffic between multiple devices; connecting both switches to a router allows all 25 workstations to share the internet connection while remaining on the same subnet. The router acts as the default gateway and DHCP server, enabling proper IP address assignment and traffic forwarding.

Answer

Connect the modem directly to the 48-port switch and then daisy-chain the 24-port switch from the 48-port switch.

Answer

Connect the modem to the 24-port switch, then connect the 48-port switch to the 24-port switch.

Answer

Connect the modem directly to the 48-port switch and connect the 24-port switch to the 48-port switch.

Question 3

A small office has a router that provides DHCP services. Several users report that they cannot access the internet, but they can still access shared folders on the local network. The technician checks one user's computer and sees an IP address of 169.254.10.25. Which of the following is the MOST likely cause of the issue?

Accepted Answer

The DHCP server is not responding. The IP address 169.254.10.25 falls within the Automatic Private IP Addressing (APIPA) range (169.254.0.0/16), which Windows assigns when a DHCP discovery broadcast fails to receive a response. Since users can still access local shared folders, local link-layer connectivity is intact, but the lack of a valid DHCP lease means they have no default gateway or DNS server configuration, preventing internet access. The most likely cause is that the DHCP server (the router) is not responding to DHCP requests.

Answer

The DNS server is not resolving domain names

Answer

The default gateway is misconfigured

Answer

A duplicate IP address exists on the network

Question 4

A network technician is installing a new IP security camera that requires Power over Ethernet (PoE) IEEE 802.3af. The technician runs a new Cat6 Ethernet cable between a PoE switch port and the camera. The switch is PoE-enabled and configured to supply power. When the camera is connected, it does not power on. The technician tests the cable with a continuity tester, and all eight wires pass. Which of the following is the most likely cause of the issue?

Accepted Answer

The switch port is administratively disabled in the switch configuration.. The most likely cause is that the switch port is administratively disabled. Even though the switch is PoE-enabled and the cable passes continuity, if the port is in a shutdown state (e.g., via the 'shutdown' command in Cisco IOS), it will not provide power or data to the camera. The technician should verify the port status with 'show interfaces' or 'show running-config' and enable it with 'no shutdown'.

Answer

The cable run exceeds the maximum length for PoE (100 meters).

Answer

The camera requires PoE+ (802.3at) and will not work with standard PoE.

Answer

The cable is terminated with T568A on one end and T568B on the other.

Question 5

A network administrator configures a new managed switch with 24 ports. All ports are in the same VLAN (VLAN 1) by default. The administrator then changes ports 1-12 to VLAN 10 and ports 13-24 to VLAN 20. Computers connected to ports in different VLANs are assigned IP addresses from the same DHCP server. Which of the following is a direct consequence of this configuration?

Accepted Answer

Computers in different VLANs cannot communicate unless a router is configured. VLANs segment a network at Layer 2, isolating broadcast domains. Without a router or Layer 3 switch configured for inter-VLAN routing, devices in different VLANs cannot communicate because they are on separate subnets and the switch will not forward frames between VLANs. The DHCP server can still assign IP addresses if it is connected to a port that is a member of both VLANs (e.g., a trunk port) or if a DHCP relay (ip helper-address) is configured on the router, but direct Layer 2 communication between VLANs is impossible without a routing device.

Answer

Computers in different VLANs can communicate directly at Layer 2

Answer

The switch will forward traffic between VLANs using internal routing

Answer

DHCP requests from VLAN 20 will be dropped by the switch

Question 6

A technician is setting up a small office network with a router that has integrated DHCP and a 24-port unmanaged switch. All computers are connected to the switch. Users report that they can access the internet but cannot see each other in Network Neighborhood. The technician checks and finds that all computers have IP addresses in the 192.168.1.0/24 range but with different subnet masks: some have 255.255.255.0, others have 255.255.0.0. Which of the following is the most likely cause?

Accepted Answer

The DHCP server is not assigning the correct subnet mask.. The DHCP server is configured to hand out IP addresses in the 192.168.1.0/24 range, but it is assigning inconsistent subnet masks (some /24, some /16). This causes computers with different subnet masks to calculate different network portions of their IP addresses, preventing them from seeing each other in Network Neighborhood even though they can reach the internet through the router's default gateway.

Answer

The switch is not forwarding broadcasts.

Answer

The router's firewall is blocking local traffic.

Answer

The computers are using different default gateways.

Question 7

A technician is setting up a small office network with a wireless router serving as the DHCP server and an unmanaged 24-port switch. All desktop computers are connected to the switch via Ethernet cables. The computers can access the internet without any issues, but they cannot see each other in the network discovery list or ping each other by IP address. The technician checks the IP configuration on one computer and finds it has an IP address of 192.168.1.10 with a subnet mask of 255.255.255.0. The technician can ping the router (192.168.1.1). Which of the following is the MOST likely cause of this issue?

Accepted Answer

The Windows firewall on each computer is blocking inbound connections.. The computers can access the internet and ping the router, confirming that the DHCP server is correctly assigning IP addresses, subnet masks, and default gateways, and that the switch is forwarding traffic properly. The inability to ping each other by IP address or see each other in network discovery strongly indicates that the Windows firewall on each computer is blocking inbound ICMP and NetBIOS/LLMNR traffic, which are required for ping responses and network discovery. This is a common default behavior of Windows Firewall in certain network profiles (e.g., Public), which blocks inbound connections unless explicitly allowed.

Answer

The DHCP server is not assigning the correct default gateway.

Answer

The switch is not properly forwarding broadcast traffic between ports.

Answer

The computers are receiving IP addresses from different VLANs.

Question 8

A user reports that their desktop computer can access shared files on the local network but cannot reach the internet. The technician checks the IP configuration and sees the address 169.254.25.100 with a subnet mask of 255.255.0.0. Other computers on the same subnet can access the internet normally. Which of the following is the MOST likely cause?

Accepted Answer

Duplicate IP address on the network. The APIPA address 169.254.25.100 indicates the computer failed to obtain a DHCP lease. Since the user can still access local shared files, the physical layer (cable and NIC) is functional, ruling out option A. A duplicate IP address can cause Windows to release its lease and auto-assign an APIPA address to avoid the conflict. Local file access may still be possible if the conflicting device is not actively using the same IP at that moment. Options B and D would not result in an APIPA address.

Answer

Faulty Ethernet cable or network interface card (NIC)

Answer

Incorrect DNS server configuration

Answer

Firewall blocking internet access

Question 9

A user reports that they can access the internet by typing an IP address (e.g., 8.8.8.8) into their web browser, but they cannot access websites using domain names (e.g., www.example.com). Which of the following network services is MOST likely not functioning correctly?

Accepted Answer

Domain Name System (DNS). The user can reach the internet via IP address but not by domain name, which indicates that the system cannot resolve human-readable names to IP addresses. The Domain Name System (DNS) is the service responsible for this translation, so a failure in DNS resolution is the most likely cause. DHCP, HTTP, and FTP are unrelated to name resolution.

Answer

Dynamic Host Configuration Protocol (DHCP)

Answer

Hypertext Transfer Protocol (HTTP)

Answer

File Transfer Protocol (FTP)

Question 10

A user reports that they can access internal network resources and the internet by IP address, but cannot browse websites using domain names. Other users on the same network can browse the internet normally. Which of the following should the technician do FIRST?

Accepted Answer

Flush the DNS cache on the user's computer. The user can access resources by IP address but not by domain name, which indicates a DNS resolution failure. Since other users on the same network can browse normally, the issue is isolated to this specific workstation. Flushing the DNS cache (ipconfig /flushdns) clears any corrupted or stale DNS entries that may be preventing successful name resolution, making it the quickest and most logical first step.

Answer

Check the DHCP server configuration

Answer

Restart the DNS service on the domain controller

Answer

Replace the network cable

Question 11

A technician is troubleshooting a desktop computer that cannot access the internet. The computer is configured with a static IP address of 10.0.0.15, subnet mask 255.255.255.0, and default gateway 10.0.0.1. The technician can ping the default gateway successfully but cannot ping the public IP address 8.8.8.8. Other devices on the same network can access the internet normally. Which of the following is the MOST likely cause?

Accepted Answer

A firewall on the computer is blocking outbound traffic. The computer can ping the default gateway (10.0.0.1) successfully, which confirms that Layer 2 and Layer 3 connectivity to the local network is working, and the static IP configuration is correct. Since other devices on the same network can access the internet normally, the issue is isolated to this specific computer. A local firewall (e.g., Windows Defender Firewall) blocking outbound ICMP or TCP traffic to public IPs like 8.8.8.8 would prevent internet access while still allowing local subnet communication, making option C the most likely cause.

Answer

The DHCP server is not functioning

Answer

The default gateway is not configured correctly on the computer

Answer

The network cable is faulty

Question 12

A user reports that they can access internal company web servers by IP address (e.g., http://10.0.1.50) but not by hostname (e.g., http://intranet). Other users on the same network can access the intranet by hostname without issue. The technician checks the computer's IP settings and sees that the DNS server address is manually set to 8.8.8.8. Which of the following is the MOST likely cause?

Accepted Answer

The computer is using an external DNS server that cannot resolve internal hostnames. The computer has its DNS server manually set to 8.8.8.8, which is a public external DNS server operated by Google. External DNS servers like 8.8.8.8 have no records for internal private hostnames (e.g., 'intranet'), so they cannot resolve them. Since the user can access internal servers by IP address but not by hostname, and other users on the same network can resolve the hostname (likely using an internal DNS server), the issue is specifically that this computer is using an external DNS server that cannot resolve internal hostnames.

Answer

The computer's subnet mask is incorrect

Answer

The internal DNS server is unreachable

Answer

The DHCP scope is exhausted

Question 13

A network administrator recently installed a new firewall to replace an older router. After the installation, users can access the internet but cannot reach internal web servers by hostname (e.g., http://intranet). They can, however, access those servers by IP address. The administrator verifies that the DNS server is functioning and other traffic between the LAN and the internal server VLAN is allowed. What is the MOST likely cause of this issue?

Accepted Answer

The firewall is blocking DNS traffic (UDP/TCP port 53) between the LAN and the internal DNS server. The firewall is blocking DNS traffic (UDP/TCP port 53) between the LAN and the internal DNS server. Since users can access the internet (external DNS queries likely go through a different path or the firewall allows outbound DNS), but internal hostname resolution fails, the most likely cause is that the firewall's rules are blocking DNS queries to the internal DNS server. This explains why IP-based access works (no DNS needed) while hostname-based access fails.

Answer

The VLAN configuration on the switch is preventing hostname resolution

Answer

The DHCP server is not assigning the correct DNS server address

Answer

The default gateway address has been misconfigured on the firewall

Question 14

A technician is troubleshooting a small office network where Windows computers can ping each other by IP address but cannot access shared folders using Universal Naming Convention (UNC) paths (e.g., \COMPUTER1\Share). The computers are all in the same workgroup and subnet. The technician checks the network settings and sees that all computers have the correct default gateway and DNS server configured. Which of the following should the technician verify?

Accepted Answer

NetBIOS over TCP/IP setting. NetBIOS over TCP/IP (NBT) is required for Windows to resolve NetBIOS names (like COMPUTER1) to IP addresses when using UNC paths. Even though ping works via DNS or hosts file, file sharing relies on NetBIOS name resolution unless DNS is configured to handle the single-label name. If NBT is disabled, the client cannot resolve the computer name in the UNC path, causing the access failure.

Answer

DHCP scope configuration

Answer

DNS suffix assignment

Answer

WINS server address

Question 15

A network technician is configuring a managed switch for a small office. The security requirement is that only specific authorized devices should be allowed to connect to the network via the switch ports. The technician wants to automatically learn the MAC addresses of devices as they connect and lock them to the port to prevent unauthorized devices from using the same port. Which switch feature should be configured to accomplish this?

Accepted Answer

Port security with sticky MAC. Port security with sticky MAC addresses allows the switch to dynamically learn MAC addresses from connected devices and then 'stick' them to the port, preventing any other device from using that port. This meets the requirement of automatically learning and locking authorized devices without manual MAC entry.

Answer

MAC filtering

Answer

VLAN tagging (IEEE 802.1Q)

Answer

Spanning Tree Protocol (STP)