220-1101 Networking Practice Test 3 — 15 Questions

Question 1

A network administrator configures a small office with a router providing DHCP. A user's computer gets an IP address of 169.254.1.5. The user cannot access the internet. The technician checks the network cable and sees link lights. Which of the following is the MOST likely cause?

Accepted Answer

The DHCP server is unreachable.. The IP address 169.254.1.5 is an Automatic Private IP Addressing (APIPA) address, which Windows assigns when a DHCP discovery broadcast fails to receive a response. Since the router is configured to provide DHCP but the client ended up with an APIPA address, the DHCP server is unreachable — likely due to a misconfigured DHCP relay, a disabled DHCP service on the router, or a VLAN mismatch blocking the broadcast. The link lights confirm Layer 1 connectivity, so the issue is at Layer 3 or above.

Answer

Incorrect subnet mask.

Answer

Duplicate IP address on the network.

Answer

DNS server misconfiguration.

Question 2

A network administrator configures a router with VLANs. Devices on VLAN 10 can successfully ping a web server (IP 192.168.20.10) on VLAN 20. However, when users on VLAN 10 attempt to access the web server via a browser using its IP address, the connection times out. The router's ACLs permit ICMP and TCP/80 traffic between VLANs. Which of the following should the administrator check NEXT?

Accepted Answer

Check if the web server's host firewall is blocking HTTP traffic. Since ICMP (ping) succeeds and the router's ACLs explicitly permit TCP/80, the issue is likely at the web server itself. The server's host firewall (e.g., Windows Defender Firewall, iptables) may be blocking inbound HTTP traffic while allowing ICMP, causing the browser connection to time out. This is the next logical check because the network path is verified working for ICMP and the ACL is confirmed permissive for TCP/80.

Answer

Verify the DHCP address assignment on VLAN 20

Answer

Review the router's ACLs for any implicit deny rules

Answer

Confirm that DNS resolution for the web server's hostname is correct

Question 3

A user reports that they can browse the internet and access all network resources by IP address, but they cannot print to the network printer by its hostname. Other users can print using the hostname without issue. The technician pings the printer's IP address from the affected computer and gets a successful reply. Which of the following should the technician check next?

Accepted Answer

The DNS server settings on the user's computer. The user can browse the internet and access resources by IP address but not by hostname, which points to a name resolution failure. Since other users can print to the network printer by hostname, the printer and DNS server are functioning correctly. The issue is isolated to the affected computer's DNS configuration, making checking the DNS server settings on the user's computer the next logical step.

Answer

The printer's firewall settings

Answer

The user's network cable

Answer

The router's NAT configuration

Question 4

A network technician is configuring a router for a small office. The office has two subnets: 192.168.1.0/24 for staff and 192.168.2.0/24 for guests. Staff can access the internet, but guests cannot. The technician confirms that both subnets have a default route to the router's WAN IP. The router has an ACL applied to the guest VLAN interface that denies all traffic to the WAN interface. What should the technician change to allow guests internet access?

Accepted Answer

Configure NAT for the guest subnet. Option D is correct because the ACL on the guest VLAN interface blocks traffic to the WAN interface, but without NAT (Network Address Translation), the router would not translate the private guest IP addresses (192.168.2.0/24) to a public IP for internet access. Even if the ACL were removed or modified, the router would still drop packets from the guest subnet destined for the internet because it lacks a NAT rule to translate the source address. Therefore, configuring NAT for the guest subnet enables outbound internet access by translating private addresses to the router's WAN IP.

Answer

Remove the ACL from the guest VLAN interface

Answer

Add a permit statement for the guest subnet to the ACL

Answer

Change the guest subnet to 192.168.1.0/24

Question 5

A user can access the internet and browse websites normally, but when they try to access a shared network drive by its hostname (\fileserver\share) the connection fails. Other users on the same network can access the drive using the hostname without issue. The technician can successfully ping the fileserver's IP address from the affected computer. Which of the following should the technician check NEXT?

Accepted Answer

The DNS server configuration on the computer. The user can browse the internet and ping the fileserver by IP, indicating basic IP connectivity and DNS resolution for external names are working. However, accessing the share by hostname fails while other users succeed, which isolates the issue to the local NetBIOS or LLMNR name resolution on the affected computer. Checking the DNS client configuration (including the primary DNS suffix and connection-specific suffixes) is the next logical step because the computer may not be appending the correct domain suffix to resolve the single-label hostname 'fileserver' to an IP address.

Answer

The firewall on the fileserver

Answer

The file and printer sharing service on the computer

Answer

The network cable connection

Question 6

A user in a small office reports that their computer cannot access the internet. The technician runs ipconfig and sees the IP address is 169.254.15.22. The technician checks the network cable and sees link lights on the NIC and the wall jack. Which of the following is the MOST likely cause of this issue?

Accepted Answer

The DHCP server is not responding or is unreachable. The IP address 169.254.15.22 is an Automatic Private IP Addressing (APIPA) address (169.254.0.0/16 range), which Windows assigns when a DHCP server cannot be reached. Since the link lights are active, the physical layer is functional, ruling out a cable fault. The most likely cause is that the DHCP server is not responding or is unreachable, preventing the client from obtaining a valid IP configuration.

Answer

The network cable is faulty

Answer

The user's computer has a duplicate IP address on the network

Answer

The subnet mask is incorrectly configured

Question 7

A network technician is troubleshooting a connectivity issue. Users on VLAN 10 (192.168.10.0/24) can access the internet but cannot reach a server on VLAN 20 (192.168.20.0/24) by IP address. The router's ACL allows all traffic between VLANs. The technician pings the server IP from a client on VLAN 10 and gets a request timed out. The technician then checks the routing table on the router and sees routes for both VLANs. Which of the following is the NEXT step to isolate the issue?

Accepted Answer

Perform a traceroute from the client to the server.. Option C is correct because a traceroute (using ICMP or UDP probes with increasing TTL values) will reveal the path packets take from the client to the server. Since the router's ACL permits all inter-VLAN traffic and routes exist for both VLANs, the issue likely lies beyond Layer 3 routing—possibly at a firewall, a misconfigured switch port, or a routing loop. Traceroute isolates exactly where packets are dropped, narrowing the troubleshooting scope.

Answer

Check the server's firewall settings.

Answer

Check the switch port for the server is in the correct VLAN.

Answer

Check the default gateway on the client.

Question 8

A user reports that they can ping the IP address 8.8.8.8 successfully from their computer, but they cannot browse the internet using website names. Other users on the same network have no issues. Which of the following should the technician check FIRST?

Accepted Answer

Verify the DNS server settings on the computer. Since the user can ping 8.8.8.8 (a public IP address) but cannot browse by website names, the issue is name resolution. DNS translates domain names to IP addresses, so the first step is to verify the DNS server settings on the affected computer. Other users working fine indicates the network and DHCP are likely healthy, isolating the problem to the client's DNS configuration.

Answer

Check the network cable and connection

Answer

Check the browser's proxy settings

Answer

Reboot the DHCP server

Question 9

A small office uses a router with DHCP service. One user reports that their computer can obtain an IP address in the 192.168.1.0/24 range, but cannot ping the default gateway (192.168.1.1). Other computers on the same network can ping the gateway and access the internet. The technician verifies the network cable shows link lights and the IP address is valid. Which of the following should the technician check NEXT?

Accepted Answer

B. The computer's subnet mask. The user's computer can obtain an IP address in the 192.168.1.0/24 range, but cannot ping the default gateway (192.168.1.1), while other devices on the same subnet can. This indicates a layer-3 connectivity issue specific to that host. The most likely cause is an incorrect subnet mask, such as 255.0.0.0 instead of 255.255.255.0, which would cause the computer to believe the gateway is on a different network and fail to send ARP requests for it, even though the IP is valid.

Answer

A. The router's firewall settings

Answer

C. The router's DHCP pool size

Answer

D. The DNS server settings

Question 10

A user reports that their computer's internet speed is much slower than expected. A speed test shows 10 Mbps, but the ISP plan provides 100 Mbps. The technician tests a laptop directly connected to the ISP modem and gets 100 Mbps. The user's computer is connected to the network via a wall jack and patch panel. The technician checks the computer's NIC and sees it is negotiating at 10 Mbps. Which of the following is the MOST likely cause?

Accepted Answer

The Ethernet cable is damaged or of poor quality.. The technician's laptop achieves 100 Mbps when directly connected to the ISP modem, proving the ISP service and modem are functioning correctly. The user's computer negotiates at only 10 Mbps, which is a classic symptom of a faulty or substandard Ethernet cable that fails to support 100BASE-TX signaling. Damaged or poor-quality cables often cause the auto-negotiation process to fall back to 10BASE-T, as the link pulses for 100 Mbps cannot be reliably exchanged.

Answer

The NIC driver is out of date.

Answer

The switch port is configured for 10 Mbps full-duplex.

Answer

The computer has a virus consuming bandwidth.

Question 11

A network technician is troubleshooting inter-VLAN routing. Clients on VLAN 10 (192.168.10.0/24) cannot communicate with servers on VLAN 20 (192.168.20.0/24). The router has subinterfaces for both VLANs and is connected to a layer 2 switch. The switch port connecting to the router is configured as an access port in VLAN 10. An ACL on the router is configured to permit all traffic between the VLANs. Which of the following is the MOST likely cause of the issue?

Accepted Answer

The switch port is not configured as a trunk. The switch port connecting to the router is configured as an access port in VLAN 10, which means it can only carry traffic for VLAN 10. For inter-VLAN routing, the router's subinterfaces need to receive frames tagged with their respective VLAN IDs. A trunk port (802.1Q) must be used on the switch side to allow both VLAN 10 and VLAN 20 traffic to reach the router. Without a trunk, frames from VLAN 20 are dropped at the switch port, preventing communication.

Answer

The ACL on the router is misconfigured

Answer

The default gateway on the servers is set incorrectly

Answer

VLAN 20 is not defined on the switch

Question 12

A technician is troubleshooting inter-subnet connectivity. The network consists of a router with two interfaces: 192.168.1.1/24 for Subnet A and 192.168.2.1/24 for Subnet B. A device on Subnet A (192.168.1.10/24) can ping the router's Subnet A interface (192.168.1.1) and other devices on Subnet A, but cannot ping a device on Subnet B (192.168.2.10/24). The device on Subnet B can ping its gateway (192.168.2.1) and other Subnet B devices. The router has IP routing enabled and no ACLs are configured. Which of the following is the MOST likely cause of the issue?

Accepted Answer

The device on Subnet A has a software firewall blocking incoming ICMP traffic. The device on Subnet A can reach its own gateway and local hosts, and the router has IP routing enabled with no ACLs, so routing is functional. The device on Subnet B can ping its own gateway, confirming that Subnet B's network and the router's interface are up. The most likely cause is that the device on Subnet A has a software firewall (e.g., Windows Defender Firewall) blocking incoming ICMP Echo Replies, which prevents the ping response from Subnet B from reaching Subnet A. This is a common scenario where outbound ICMP is allowed but inbound ICMP is blocked by the host firewall.

Answer

The router's interface on Subnet A is administratively down

Answer

The subnet mask on the device in Subnet B is incorrect

Answer

The switch port connecting the router to Subnet B is configured as an access port in the wrong VLAN

Question 13

A user reports that they cannot access the company's external website at www.company.com from their workstation. Other users on the same network can access the website without issues. The technician runs nslookup www.company.com and receives the correct public IP address. The technician then pings that IP address and gets a successful reply. Which of the following is the MOST likely cause of the issue?

Accepted Answer

The user's hosts file has an incorrect mapping for www.company.com. The nslookup returned the correct public IP, and a ping to that IP succeeded, confirming DNS resolution and network connectivity are working. However, the user's browser cannot reach the website, which points to a local redirection issue. The hosts file (located at %SystemRoot%\System32\drivers\etc\hosts) can override DNS by mapping a domain to a different IP; an incorrect entry for www.company.com would cause the browser to attempt to connect to the wrong address, even though the network path is functional.

Answer

The website's SSL certificate has expired

Answer

The user's web browser needs to be updated

Answer

The company's firewall is blocking the user's IP address

Question 14

A user reports that they can access the company's internal web server by IP address (192.168.2.10) but not by its hostname (intranet.company.local). Other users on the same network can access the server by hostname without issues. The technician checks the user's network settings and sees that the DNS server is correctly set to the company's internal DNS server. Which of the following should the technician check NEXT?

Accepted Answer

Check the local hosts file for an incorrect entry. Since the user can reach the server by IP but not by hostname, and other users can resolve the hostname correctly, the issue is isolated to this specific workstation's name resolution. An incorrect entry in the local hosts file (C:\Windows\System32\drivers\etc\hosts) can override DNS lookups, mapping the hostname to a wrong or unreachable IP. This explains why the user fails to resolve 'intranet.company.local' while the DNS server setting itself is correct.

Answer

Check the default gateway configuration

Answer

Run ipconfig /flushdns to clear the DNS resolver cache

Answer

Change the DNS server to a public DNS server like 8.8.8.8

Question 15

A user reports that they can access internal company servers by IP address but cannot access the internet. The user can ping the default gateway successfully. Other users on the same subnet have full internet access. The technician checks the user's IP configuration and sees that the IP address, subnet mask, and default gateway are correct. The DNS server address is set to the company's internal DNS server (10.0.1.10). Which of the following is the MOST likely cause of the issue?

Accepted Answer

The user's computer has a stale DNS cache. The user can access internal servers by IP and ping the default gateway, confirming that Layer 3 connectivity is intact. Since other users on the same subnet have full internet access, the issue is isolated to this specific computer. A stale DNS cache can prevent name resolution for external domains while leaving internal IP-based access unaffected, which matches the symptom exactly.

Answer

The DHCP scope is exhausted and the user received an APIPA address

Answer

The user has an incorrect default gateway configured

Answer

The user's subnet mask is incorrect