220-1101 Network Services — Timed 10 Questions

Question 1

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?

Accepted Answer

The DNS A record is incorrect. 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.

Answer

The DHCP server assigned the wrong IP to the server

Answer

The router's port forwarding is misconfigured

Answer

The server's firewall is blocking DNS queries

Question 2

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 Users report that they occasionally see outdated content or are asked to log in repeatedly.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?

Accepted Answer

Session persistence (sticky sessions). 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.

Answer

DNS round-robin

Answer

DHCP reservation

Answer

Port forwarding

Question 3

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?

Accepted Answer

DNS server. With a static IP, the user must also configure a DNS server address to resolve domain names. Without DNS, they can communicate locally but cannot access internet resources by name. DHCP would auto-assign these settings, but static configuration requires manual entry.

Answer

DHCP server

Answer

NAT

Answer

Proxy server

Question 4

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?

Accepted Answer

VPN. A VPN (Virtual Private Network) creates an encrypted tunnel between a remote device and the corporate network, ensuring secure data transmission over the internet. DHCP and DNS do not provide encryption, and port forwarding alone does not secure remote access.

Answer

DHCP

Answer

DNS

Answer

Port forwarding

Question 5

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?

Accepted Answer

The user's DNS settings are incorrect. 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.

Answer

The DHCP server is out of addresses

Answer

The DNS server is down

Answer

The router's NAT is misconfigured

Question 6

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?

Accepted Answer

The port forwarding rule uses the wrong internal port. 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.

Answer

The DNS server is misconfigured

Answer

The NAT table is full

Answer

The DHCP scope is exhausted

Question 7

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?

Accepted Answer

DNS. The ability to ping an external IP but not access websites indicates that DNS resolution is failing. DNS translates domain names to IP addresses, and without it, web browsing fails even if the internet connection is working. The DHCP server or static DNS settings should be checked.

Answer

DHCP

Answer

NAT

Answer

Proxy

Question 8

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?

Accepted Answer

Port forwarding. Port forwarding allows external requests on a specific port to be redirected to an internal IP address and port. This is the standard method to make internal servers accessible from the internet when using NAT. Other options like DHCP or DNS do not handle port-based redirection.

Answer

DHCP

Answer

DNS

Answer

VPN

Question 9

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?

Accepted Answer

QoS. Quality of Service (QoS) is used to prioritize time-sensitive traffic like VoIP, reducing latency and jitter during congestion. DHCP assigns IPs, DNS resolves names, and VPN encrypts traffic but none prioritize packets. QoS markings (e.g., DSCP) ensure voice packets are handled first.

Answer

DHCP

Answer

DNS

Answer

VPN

Question 10

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?

Accepted Answer

DHCP scope. The DHCP server configuration controls IP address ranges (scopes) and lease times. By modifying the DHCP scope, the administrator can set the desired IP range and lease duration. DNS and NAT do not manage IP assignment, and QoS handles traffic prioritization.

Answer

DNS zone file

Answer

NAT rules

Answer

QoS policy