CompTIA N10-009 Practice Exams
Last updated on Oct 01,2026- Exam Code: N10-009
- Exam Name: CompTIA Network+ Certification
- Certification Provider: CompTIA
- Latest update: Oct 01,2026
Users at a satellite office are experiencing issues when using videoconferencing.
Which of the following should a technician focus on first to rectify these issues?
- A . Quality of service
- B . Network signal
- C . Time to live
- D . Load balancing
A
Explanation:
Quality of Service (QoS) ensures video conferencing receives priority bandwidth to prevent latency, jitter, and packet loss.
QoS settings prioritize real-time traffic, ensuring smooth performance.
Reference: CompTIA Network+ (N10-009) Official Study Guide C Section: Network Performance Optimization
An organization wants to ensure that incoming emails were sent from a trusted source.
Which of the following DNS records is used to verify the source?
- A . TXT
- B . AAAA
- C . CNAME
- D . MX
A
Explanation:
A TXT record can be used to store SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail) information, which help verify that an email has been sent from a trusted source.
A network administrator installed a new VLAN to the network after a company added an additional floor to the office. Users are unable to obtain an IP address on the new VLAN, but ports on existing VLANs are working properly.
Which of the following configurations should the administrator update?
- A . Scope size
- B . Address reservations
- C . Lease time
- D . IP helper
D
Explanation:
Comprehensive and Detailed
When a new VLAN is created, it typically exists on a different subnet. If DHCP servers are on a different VLAN, the network needs an IP helper address to forward DHCP requests correctly. Without it, clients in the new VLAN won’t receive an IP address.
Breakdown of Options:
A network administrator’s device is experiencing severe Wi-Fi interference within the corporate headquarters causing the device to constantly drop off the network.
Which of the following is most likely the cause of the issue?
- A . Too much wireless reflection
- B . Too much wireless absorption
- C . Too many wireless repeaters
- D . Too many client connections
A
Explanation:
Reference: CompTIA Network+ Certification Exam Objectives – Wireless Networks section.
A small business is deploying new phones, and some of the phones have full HD videoconferencing features. The Chief Information Officer (CIO) is concerned that the network might not be able to handle the traffic if it reaches a certain threshold.
Which of the following can the network engineer configure to help ease these concerns?
- A . A VLAN with 100Mbps speed limits
- B . An IP helper to direct VoIP traffic
- C . A smaller subnet mask
- D . Full duplex on all user ports
D
Explanation:
Comprehensive and Detailed
Full duplex mode allows devices to send and receive data simultaneously, improving network performance and reducing congestion, which is critical for VoIP and video conferencing.
Breakdown of Options:
Which of the following is a major difference between an IPS and IDS?
- A . An IPS needs to be installed in line with traffic and an IDS does not.
- B . An IPS is signature-based and an IDS is not.
- C . An IPS is less susceptible to false positives than an IDS.
- D . An IPS requires less administrative overhead than an IDS.
A
Explanation:
Comprehensive and Detailed
The key difference is that an Intrusion Prevention System (IPS) is installed in line with network traffic,
allowing it to actively block threats. In contrast, an Intrusion Detection System (IDS) only monitors
and alerts without actively blocking traffic.
Breakdown of Options:
A technician needs to set up a wireless connection that utilizes MIMO on non-overlapping channels.
Which of the following would be the best choice?
- A . 802.11a
- B . 802.11b
- C . 802.11g
- D . 802.11n
D
Explanation:
The 802.11n standard supports MIMO (Multiple Input Multiple Output), which allows multiple antennas to increase data throughput and improve reliability. Additionally, it uses non-overlapping channels in the 5 GHz band (and optionally the 2.4 GHz band), making it a good choice for high-speed, interference-resistant wireless connections. (Reference: CompTIA Network+ Study Guide, Chapter on Wireless Technologies)
A network administrator is configuring a network for a new site that will have 150 users. Within the next year, the site is expected to grow by ten users. Each user will have two IP addresses, one for a computer and one for a phone connected to the network.
Which of the following classful IPv4 address ranges will be best-suited for the network?
- A . Class D
- B . Class B
- C . Class A
- D . Class C
D
Explanation:
IPv4 addresses are divided into classes:
Class A: Supports 16,777,214 hosts (large enterprises).
Class B: Supports 65,534 hosts (medium to large networks).
Class C: Supports 254 hosts (small to medium networks).
Class D: Used for multicast, not for assigning IPs to hosts.
Step-by-step Calculation:
The network will have 150 users initially, with a projected growth of 10 users, totaling 160 users.
Each user has two devices, so 160 × 2 = 320 IP addresses needed.
A Class C subnet has 254 usable IPs by default, which is not sufficient.
A Class B subnet can support thousands of hosts, making it the most appropriate option.
Incorrect Options:
A user is unable to navigate to a website because the provided URL is not resolving to the correct IP address. Other users are able to navigate to the intended website without issue.
Which of the following is most likely causing this issue?
- A . Hosts file
- B . Self-signed certificate
- C . Nameserver record
- D . IP helperANS
A
Explanation:
Role of the Hosts File:
The hosts file is a local file on a computer that maps hostnames to IP addresses. It can be used to override DNS resolution by providing a static mapping of a hostname to an IP address. Common Issues with the Hosts File:
If an incorrect IP address is mapped to a hostname in the hosts file, it can cause the computer to resolve the hostname to the wrong IP address. This can lead to navigation issues for specific websites while other users, relying on DNS, do not face the same problem.
Why Other Options are Less Likely:
Self-signed certificate: Relates to SSL/TLS and would cause a security warning, not a navigation failure.
Nameserver record: Affects all users, not just one.
IP helper: Used to forward DHCP requests and is unrelated to DNS resolution issues.
Troubleshooting Steps:
Check the hosts file on the affected user’s computer (C:WindowsSystem32driversetchosts on Windows or /etc/hosts on Unix/Linux).
Look for entries that map the problematic hostname to an incorrect IP address and correct or remove them.
Reference: CompTIA Network+ study materials and system administration documentation.
While troubleshooting a VoIP handset connection, a technician’s laptop is able to successfully connect to network resources using the same port. The technician needs to identify the port on the switch.
Which of the following should the technician use to determine the switch and port?
- A . LLDP
- B . IKE
- C . VLAN
- D . netstat
A
Explanation:
Link Layer Discovery Protocol (LLDP) is a network protocol used for discovering devices and their capabilities on a local area network, primarily at the data link layer (Layer 2). It helps in identifying the connected switch and the specific port to which a device is connected. When troubleshooting a VoIP handset connection, the technician can use LLDP to determine the exact switch and port where the handset is connected. This protocol is widely used in network management to facilitate the discovery of network topology and simplify troubleshooting.
Other options such as IKE (Internet Key Exchange), VLAN (Virtual LAN), and netstat (network statistics) are not suitable for identifying the switch and port information. IKE is used in setting up secure IPsec connections, VLAN is used for segmenting networks, and netstat provides information about active connections and listening ports on a host but not for discovering switch port details.
Reference: CompTIA Network+ Certification Exam Objectives – Network Troubleshooting and Tools section.