A.The DHCP server is out of addresses.
B.The DNS server address is incorrect.
C.The RADIUS server is offline.
AnswerD
A mismatch in the EAP method (e.g., requiring certificates but using passwords) will cause authentication failure for that client.
30 questions · Network Services topic · All types, answers revealed
A mismatch in the EAP method (e.g., requiring certificates but using passwords) will cause authentication failure for that client.
A technician is troubleshooting a network where users can access the internet but cannot reach a specific internal web server by its hostname. The server's IP is 10.0.0.5, and pinging 10.0.0.5 works. The technician checks the DNS server and finds an A record for the server's name pointing to 10.0.0.10. What is the most likely issue?
The A record points to 10.0.0.10 instead of 10.0.0.5, so DNS resolves to the wrong IP, preventing access by hostname.
Why this answer
The DNS A record points to the wrong IP address (10.0.0.10 instead of 10.0.0.5), causing hostname resolution to fail for that server. This is a common DNS misconfiguration where the record does not match the actual server IP. Correcting the A record resolves the issue.
RADIUS authenticates against its user database; a missing account prevents that user's login.
A network administrator is deploying a new wireless network that requires users to authenticate using their domain credentials. The network uses WPA2-Enterprise. Which service must be configured to validate these credentials?
A small office has a single internet connection and needs to allow multiple internal devices to share that connection. The router's public IP is assigned by the ISP. Which network service must be enabled on the router to allow internal devices to communicate with external servers?
NAT translates private internal IP addresses to the router's public IP, allowing multiple devices to share the internet connection.
Why this answer
NAT (Network Address Translation) allows multiple devices on a private network to share a single public IP address by translating their private IPs to the public IP. DHCP assigns internal IPs but does not enable internet sharing. DNS resolves names, and PAT is a form of NAT but not the broad service name.
A company deploys a load balancer to distribute traffic across three web servers. Users report that they occasionally see outdated content or are asked to log in repeatedly. Which network service configuration is most likely missing to maintain session persistence?
Session persistence ensures a user is directed to the same server for the duration of their session, preventing login and data inconsistencies.
Why this answer
Load balancers distribute traffic but without session persistence (sticky sessions), a user may be directed to different servers during a session, losing login state or cached data. Configuring the load balancer to use cookies or source IP affinity ensures the same server handles the session. DNS round-robin alone would cause similar issues.
A user configures their laptop to use a static IP address, subnet mask, and default gateway. They can ping other devices on the same subnet but cannot reach the internet. What network service is most likely missing from their configuration?
Without a DNS server address, the laptop cannot resolve domain names, making internet access fail even with correct IP settings.
A company wants to allow employees to securely access the corporate network from home using their laptops. Which network service should be deployed to provide encrypted remote access?
VPN establishes an encrypted connection over the internet, enabling secure remote access to the corporate network.
A user reports that they can access internal resources using IP addresses but cannot access them using hostnames. Other users on the same network have no issues. What is the most likely cause?
Incorrect DNS settings on the user's device prevent hostname resolution while IP-based access still works.
Why this answer
The ability to use IP addresses but not hostnames points to a DNS resolution problem on the user's device. This could be due to a misconfigured DNS server address in the network settings or a local hosts file issue. Other users working normally suggests the problem is client-specific.
A company's web server is accessible from the internet, but users report that the website loads slowly. The server's public IP is 203.0.113.10, and the internal IP is 192.168.1.10. The network administrator notices that the router's port forwarding rule is set to forward port 80 to 192.168.1.10:8080. What is the likely cause of the slow performance?
If the web server listens on port 80 but the rule forwards to 8080, traffic is sent to a closed port, causing timeouts or slowness.
Why this answer
Port forwarding should map external port 80 to the server's internal port 80, not 8080 unless the server listens on 8080. If the server listens on port 80, the mismatch causes connection delays or errors as the router forwards to a closed port. Correcting the internal port resolves the issue.
A user reports that they cannot access any websites, but they can ping the IP address of a public DNS server (8.8.8.8). What is the most likely misconfigured network service?
DNS resolves domain names; without it, domain-based access fails even though IP-based connectivity works.
A small office uses a single public IP address for internet access. The network administrator wants internal web servers to be reachable from the internet on port 80. Which network service should be configured on the router to allow this?
Port forwarding maps an external port to an internal IP and port, enabling external access to internal services.
A technician is configuring a new file server and wants to ensure that when users type \\fileserver in File Explorer, it resolves to the correct IP address. The network uses a Windows domain with Active Directory. Which network service should the technician configure to allow hostname resolution for this server?
DNS resolves hostnames like 'fileserver' to IP addresses. Adding an A record in the DNS zone will allow users to connect via the hostname.
A small business reports that employees can access the internet but cannot reach the internal company website hosted on a local server. The server's IP address is 192.168.1.10, and clients use DHCP. What is the most likely cause?
A missing A or host record prevents name resolution for the internal site, while internet DNS works fine.
Why this answer
This question tests understanding of DNS resolution for internal resources. When a server hosts an internal website, clients need a DNS record (often a host record) to resolve its hostname to the private IP address. Without it, clients can't reach the site by name even with internet access.
A technician is setting up a new file server and wants to ensure that clients can automatically obtain the server's IP address via a friendly name without manual configuration. Which network service should be configured on the server?
DNS maps hostnames to IP addresses, enabling name-based access.
A technician is troubleshooting an issue where a user's computer can access the internet but cannot connect to a network printer by its IP address. The printer is on the same subnet and is powered on. Pinging the printer's IP from the computer fails. Which network service is most likely causing the problem?
ARP resolves the printer's IP to its MAC address. If ARP fails, the computer cannot send frames to the printer, causing ping failure.
Why this answer
Since the printer is on the same subnet, no routing is needed; ARP is required to resolve the printer's IP to its MAC address. If ARP fails, the ping will fail. DNS is not used when connecting by IP, and DHCP is not involved since the computer already has an IP.
A technician needs to configure a router to allow internal users to access a web server on the internet using a public IP address. The web server is hosted internally on a private IP. Which network service must be configured on the router?
NAT (specifically port forwarding) maps the public IP to the internal server's private IP.
A network administrator is setting up a new branch office. The branch router must automatically obtain a public IP address from the ISP, and internal devices must receive private IP addresses from the router. Which combination of network services should be configured on the router?
The router acts as a DHCP client on the WAN side to get a public IP, and as a DHCP server on the LAN side to assign private IPs.
Why this answer
The router needs DHCP client mode to obtain a public IP from the ISP, and DHCP server mode to assign private IPs to internal devices. DNS and NAT are also needed but the question asks for the services that provide IP addresses. NAT is required to translate private IPs to the public IP for internet access.
A user reports that their computer cannot connect to the internet after being moved to a new office. The computer receives an IP address starting with 169.254.x.x. Which network service is failing to provide a valid IP configuration?
DHCP assigns IP addresses. The 169.254.x.x address is an APIPA address, meaning the DHCP server did not respond.
A company uses a proxy server for internet access. Users report that they can access internal websites but cannot reach external sites. The proxy server's IP is configured in the browser settings. Which network service is most likely failing?
The proxy server is responsible for forwarding external requests. If it is down or misconfigured, users cannot reach external sites while internal access remains unaffected.
A company uses a cloud-based VoIP service, and users report intermittent call drops and poor audio quality. Network monitoring shows high jitter and packet loss. Which service is most likely contributing to the problem?
Without QoS, real-time traffic like VoIP competes with other data, causing jitter and packet loss.
A user complains that they cannot access any websites, but they can ping external IP addresses like 8.8.8.8 successfully. Other devices on the same network work fine. Which network service is most likely failing on this user's computer?
DNS resolves domain names to IPs. The user can ping by IP but not by name, so DNS is likely misconfigured or not responding on that machine.
A technician is troubleshooting a network where users can access the internet but cannot connect to a specific internal application server by its hostname. Pinging the server's IP address works. The DNS server is configured correctly for external names. What is the most likely cause?
Without an A record, DNS cannot resolve the hostname to the server's IP, even though the server is reachable by IP.
Why this answer
The DNS server resolves external names but not the internal hostname, indicating a missing or incorrect DNS record (A or CNAME) for the internal server. DHCP is not involved, and NAT is working since internet access is fine. A proxy server could interfere but is less likely than a missing DNS record.
A user reports that their computer's clock is consistently off by several minutes, causing authentication failures with the domain. The network uses Active Directory. Which service should be checked first?
NTP synchronizes system clocks, preventing time-related authentication issues.
Why this answer
This question tests basic understanding of NTP. Time synchronization is critical for Kerberos authentication in Active Directory. NTP keeps clocks accurate, and a drift can cause logon failures.
A technician is configuring a network for a new branch office. The branch has 50 users and needs to access resources at the main office via a secure tunnel over the internet. Which service is required to establish this connection?
VPN creates an encrypted tunnel over the internet for secure communication between sites.
A customer complains that their VoIP phone intermittently drops calls. A technician checks the network and finds high latency and jitter during peak hours. Which network service should be configured to prioritize VoIP traffic?
QoS prioritizes VoIP traffic to maintain call quality by reducing latency and jitter.
Why this answer
A customer reports that their laptop can connect to the internet via a wired connection but cannot access any network shares or printers by hostname. They can ping the IP address of the file server. Which network service is most likely misconfigured?
DNS resolves hostnames to IP addresses. Since the customer can access resources by IP but not by hostname, DNS is misconfigured or not resolving local names.
Why this answer
This scenario describes a failure in name resolution for local network resources. DNS translates hostnames to IP addresses; since the customer can ping by IP but not by name, the DNS service is the likely culprit. DHCP provides IP configuration, not name resolution, and ARP resolves IP to MAC addresses.
A company's internal website is accessible by IP address but not by its hostname. The website is hosted on a server with a static IP. Which service is most likely misconfigured?
Why this answer
This question tests DNS resolution for internal resources. Access by IP works, so the server is reachable. The problem is name resolution, which points to a missing or incorrect DNS record for that hostname.
A network administrator wants to ensure that all devices on a subnet automatically receive IP addresses from a specific range, and that the lease time is set to 8 hours. Which configuration file or service should be modified?
The DHCP scope defines the IP address range and lease time for automatic assignment to clients.
A company's web server is hosted internally and must be accessible from the internet using the domain name www.company.com. The public IP address of the router is 203.0.113.5. Which two network services must be correctly configured to make this work?
DNS resolves the domain to the public IP, and NAT (with port forwarding) directs traffic to the internal server.
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