N10-009 CompTIA Network+ Certification Exam Free Practice Exam Questions (2026 Updated)

The correct answer is A. Nmap. Nmap (Network Mapper) is a powerful network scanning and reconnaissance tool specifically designed to gather detailed information about hosts on a network. According to CompTIA Network+ N10-009 objectives, Nmap can be used to identify open ports, running services, and even the operating system of a target device through techniques such as TCP/UDP scanning and OS fingerprinting.

This makes Nmap the best choice when a systems administrator needs a comprehensive view of a server’s exposure and configuration. It can enumerate services (e.g., HTTP, SSH), detect service versions, and determine which ports are open, closed, or filtered.

The other options are more limited in scope. Traceroute is used to map the path packets take across a network and identify latency or routing issues, but it does not provide service or OS details. Netstat shows active connections and listening ports on a local machine but does not perform remote OS detection or full service enumeration. Ping simply tests connectivity and reachability using ICMP and does not provide detailed system information.

Therefore, Nmap is the most appropriate and comprehensive tool for this requirement.

The correct answer is D: Increase the scope to 10.8.100.50 – 10.8.100.175. According to the CompTIA Network+ N10-009 objectives, proper DHCP scope configuration is essential to ensure all hosts can obtain valid IP addresses and communicate beyond their local segment.

In this scenario, the DHCP scope is configured for 10.8.100.50 through 10.8.100.150, while a reservation range exists from 10.8.100.151 through 10.8.100.175. The network scan shows that IP addresses up to 10.8.100.175 are already in use. This indicates that some devices are either statically assigned addresses outside the active scope or are failing to receive valid DHCP leases, causing the new laptops to communicate only with each other—often a sign of APIPA or improper addressing.

To ensure full connectivity, the DHCP scope must be expanded to include the entire range of addresses that are actively in use, including the reserved addresses. Option D correctly extends the scope to 10.8.100.175 without overlapping lower addresses that may be statically assigned or intentionally excluded.

The Network+ objectives emphasize avoiding address conflicts and ensuring DHCP scopes align with real-world network usage. Expanding the scope to include all valid addresses ensures that all laptops can obtain proper IP configuration, default gateway information, and full network connectivity.

The switch with the lowest STP priority becomes the root bridge.In the given table, core-sw01 has the lowest priority value of 24576. Therefore, it will be elected as the root bridge in the Spanning Tree Protocol topology.

A content filter is the correct solution because it can block access to specific categories of websites, domains, URLs, or application types, including social media. Content filtering is commonly used to enforce acceptable use policies, reduce risk, improve productivity, and prevent users from accessing prohibited or unsafe web content. In this scenario, the requirement is to stop access to social media websites, so filtering web content by category or URL is the most direct control.

The CompTIA Network+ N10-009 objectives include network security concepts, access control, filtering, and security appliances or services. A content filter may be implemented through a secure web gateway, firewall, DNS filtering platform, proxy server, cloud security platform, or endpoint security solution.

Network Access Control, or NAC, controls whether devices are allowed to connect to the network based on identity, posture, or policy. A screened subnet, also called a DMZ, is used to isolate public-facing services. A VPN provides encrypted connectivity but does not inherently block social media access. Therefore, content filtering is the most appropriate answer.

Understanding 2.4GHz Interference:

The 2.4GHz frequency range is commonly used by many devices, including Wi-Fi, Bluetooth, and various industrial equipment. This can lead to interference and degraded performance.

Mitigation Strategies:

5GHz Frequency:

The 5GHz frequency band offers more channels and less interference compared to the 2.4GHz band. Devices operating on 5GHz are less likely to encounter interference from other devices, including industrial equipment.

Non-overlapping Channels:

In the 2.4GHz band, using non-overlapping channels (such as channels 1, 6, and 11) can help reduce interference. Non-overlapping channels do not interfere with each other, providing clearer communication paths for Wi-Fi signals.

Why Other Options are Less Effective:

Mesh Network: While useful for extending network coverage, a mesh network does not inherently address interference issues.

Omnidirectional Antenna: This type of antenna broadcasts signals in all directions but does not mitigate interference.

Captive Portal: A web page that users must view and interact with before accessing a network, unrelated to frequency interference.

Ad Hoc Network: A decentralized wireless network that does not address interference issues directly.

Implementation:

Switch Wi-Fi devices to the 5GHz band if supported by the network infrastructure and client devices.

Configure Wi-Fi access points to use non-overlapping channels within the 2.4GHz band to minimize interference.

A cold site is a backup facility that provides infrastructure (such as power, cooling, and space) but does not have active IT resources installed. When a disaster occurs, IT teams must bring in and configure all necessary hardware and software before services can resume. This process can take weeks or longer—which matches the scenario described.

•Why not the other options?

•Hot site (A) – A hot site is a fully operational backup facility with up-to-date data and pre-configured hardware, allowing almost instant failover (minutes to hours).

•Warm site (B) – A warm site has pre-installed hardware and some software/configurations, but it requires some setup before becoming fully operational (hours to a few days).

•Active-active approach (D) – This means that multiple sites run simultaneously with load balancing, ensuring no downtime in case of a failure.

The default gateway for a network should be an IP address within the subnet, but not the broadcast address. In this case:

IP: 192.163.1.15

Subnet Mask: 255.255.255.0

This means the network range is: 192.163.1.0 - 192.163.1.255

192.163.1.255 is the broadcast address for this subnet, so it cannot be used as a gateway.

Hence, the device fails to communicate outside its subnet because it ' s trying to use a broadcast address as its gateway.

✅ The issue is clearly with the gateway configuration.

Shielded twisted pair, or STP, is the best choice because the problem is related to electromagnetic interference, and the requirement is to keep costs low. STP cabling includes shielding around the twisted pairs or cable bundle to reduce the effects of external interference from electrical equipment, appliances, fluorescent lighting, microwave ovens, motors, and other sources. Since the cable is routed near a break room with known interference, replacing unshielded cabling with shielded twisted pair is the most practical and cost-effective solution.

The CompTIA Network+ N10-009 objectives require understanding copper cabling types, interference, and appropriate media selection. Fiber-optic cabling, including single-mode and multimode fiber, is immune to electromagnetic interference and could solve the issue, but it is generally more expensive than copper due to optics, termination, installation, and equipment requirements. Unshielded twisted pair is inexpensive but provides less protection against interference. Because the issue is caused by interference and the organization wants to control cost, STP provides the best balance of performance, protection, and affordability.

A transceiver is the correct answer because it is the Layer 1 (Physical Layer) component that physically terminates and converts fiber-optic signals on an SFP-capable switch. In CompTIA Network+ N10-009 objectives, transceivers—such as SFP, SFP+, QSFP, and QSFP+ modules—are explicitly identified as physical interface components that handle signal transmission and reception. These modules convert electrical signals from the switch into optical signals for fiber cabling (and vice versa), enabling communication over different media types and distances.

A modem is also a Layer 1 device, but its purpose is to modulate and demodulate signals for WAN technologies such as DSL or cable—it does not terminate fiber connections on switches. An Ethernet NIC provides network access for end devices like computers and servers and typically terminates copper Ethernet, not modular fiber interfaces on switches. A repeater regenerates and amplifies signals to extend cable distances but does not provide fiber termination or media conversion at a switch port.

According to Network+ standards, SFP transceivers are essential for flexible network design, allowing administrators to select appropriate fiber types (single-mode or multi-mode), wavelengths, and distances while remaining compliant with physical layer requirements.

To prioritize traffic and utilize a constrained link more effectively, the engineer should implement QoS (Quality of Service). QoS is a set of mechanisms that classifies and marks traffic (for example, voice, video, business-critical apps) and then applies queuing and scheduling behaviors to ensure important traffic receives preferential treatment during congestion. Network+ objectives commonly connect QoS to supporting real-time applications (VoIP/video) by reducing latency, jitter, and packet loss, while preventing less critical traffic (bulk transfers, updates) from consuming all available bandwidth. Techniques can include traffic classification, DSCP marking, priority queuing, and traffic shaping/policing.

A CDN improves content delivery by caching closer to users, but it doesn’t provide link-level prioritization for all traffic types. A VPN provides secure tunneling/encryption, not prioritization. TTL (Time To Live) is an IP header value used to prevent routing loops by limiting packet lifespan; it does not manage bandwidth or prioritize flows. QoS is the standard solution when the goal is to control how bandwidth is allocated under load and to ensure critical services remain performant.

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URL filtering can block access to websites based on their domain or country code TLDs (e.g., .cn, .ru). This is the correct method to block by location identifiers in URLs.

B. Content filtering blocks based on keywords or categories within websites, not country code.

C. DNS poisoning is an attack, not a control mechanism.

D. MAC filtering restricts devices, not websites.

References (CompTIA Network+ N10-009):

Domain: Network Security — Filtering technologies, URL vs content filtering.

When two devices on different subnets are unable to communicate, but can communicate with other devices on their own subnet, the issue is most often related to routing. Devices on different subnets require a default gateway to route traffic between networks.

If the default gateway is incorrectly configured, the device won’t know how to reach other subnets.

Faulty cables (Option B) or duplex mismatches (Option C) would likely cause connectivity issues even within the local subnet, which is not the case here.

VLAN mismatches (Option D) are typically issues with switch port configurations and would likely cause total loss of connectivity, including within the same subnet.

✅ So, the most probable and logical cause is an incorrect default gateway.

The best solution here is band steering. Band steering allows modern wireless access points to automatically direct dual-band capable clients toward the 5 GHz band instead of the crowded 2.4 GHz band. The 5 GHz band has more available non-overlapping channels and can provide faster speeds with less interference, especially in dense environments. Devices that only support 2.4 GHz will remain on that band, while compatible devices enjoy the improved performance of 5 GHz.

A. 802.1X is a port-based network access control method for authentication. While important for security, it does not affect wireless channel utilization or client throughput.

B. MIMO (Multiple Input, Multiple Output) is a technology that improves throughput by using multiple antennas to send/receive simultaneously, but it does not actively steer clients between frequency bands.

C. ESSID (Extended Service Set Identifier) is just the network name for a set of APs in the same WLAN; it has no role in optimizing performance by band.

By implementing band steering, administrators reduce channel overlap on the 2.4 GHz band, improve spectral efficiency, and provide higher performance to capable devices, directly meeting the requirements described in the scenario.

References (CompTIA Network+ N10-009):

Domain: Networking Concepts — Wireless optimization, band steering, dual-band client management.

A heat map is the most useful tool for ensuring wireless coverage in a new office building. A wireless heat map visually represents signal strength, coverage areas, dead zones, interference, and access point placement. It helps administrators determine whether users will have adequate wireless connectivity throughout the building, including offices, conference rooms, hallways, lobbies, and shared workspaces.

The CompTIA Network+ N10-009 objectives include wireless networking concepts, site surveys, signal strength, interference, channel planning, and access point placement. A heat map supports these objectives by showing how wireless signals behave in the real environment. This is important because walls, doors, metal structures, glass, furniture, electrical equipment, and building materials can affect wireless performance.

A building layout is helpful for planning, but it does not show actual or predicted wireless signal coverage by itself. IDF location is important for cabling and network distribution, but it does not confirm wireless coverage. A cable diagram documents physical cabling paths and connections, but it does not show Wi-Fi signal strength. Therefore, a heat map is the best answer.

The correct answer is D. Hot site. In CompTIA Network+ N10-009, disaster recovery and business continuity concepts include understanding recovery site types and how quickly they can restore operations after a major outage or catastrophe. A hot site provides the fastest recovery because it is a fully operational alternate location with the necessary network infrastructure, hardware, systems, connectivity, and often replicated data already available. Since the environment is prepared and ready to assume production workloads, organizations can fail over to a hot site with minimal downtime.

A warm site is partially prepared and may have network connectivity and some hardware in place, but it usually requires additional configuration, data restoration, or system activation before services can fully resume. A cold site provides only basic facilities, such as space, power, and cooling, but lacks most operational equipment and therefore has the longest recovery time. Asynchronous replication is a data replication method where changes are copied after they occur, but it is not itself a complete recovery location and may involve some data loss depending on timing.

Because the question asks which option allows the fastest recovery during a catastrophe, the best choice is a hot site.

Role of an Access Point (AP):

Wireless to Wired Conversion: An access point (AP) is a device that allows wireless devices to connect to a wired network using Wi-Fi. It converts wireless signals (radio waves) into electronic signals that can be understood by wired network devices.

Functionality:

Signal Conversion: The AP receives wireless signals from devices such as laptops, smartphones, and tablets, converts them into electronic signals, and transmits them over the wired network.

Connectivity: APs provide a bridge between wireless and wired segments of the network, enabling seamless communication.

Comparison with Other Devices:

Router: Directs traffic between different networks and may include built-in AP functionality but is not primarily responsible for converting wireless to electronic signals.

Firewall: Protects the network by controlling incoming and outgoing traffic based on security rules, not involved in signal conversion.

Load Balancer: Distributes network or application traffic across multiple servers to ensure reliability and performance, not involved in signal conversion.

Deployment:

APs are commonly used in environments where wireless connectivity is needed, such as offices, homes, and public spaces. They enhance mobility and provide flexible network access.

Comprehensive and Detailed Explanation (aligned to N10-009):

APIs (Application Programming Interfaces) allow automation tools and scripts to push configurations to network devices programmatically. Modern network automation platforms rely on APIs to ensure consistency and scalability.

A. RDP is remote desktop for Windows systems, not automation.

B. Telnet is insecure and manual.

C. GUI requires manual configuration, not automation.

References (CompTIA Network+ N10-009):

Domain: Network Operations — Automation, orchestration, APIs in network management.

VLANs (Virtual Local Area Networks) segment network traffic by department, allowing ACLs (Access Control Lists) to be applied based on VLAN membership, improving security and resource isolation.

Breakdown of Options:

A. VLAN – Correct answer. VLANs enable logical network segmentation, allowing ACLs per department.

B. DHCP – Assigns IP addresses but does not control access.

C. VPN – Provides remote access, not segmentation within a network.

D. STP – Prevents switching loops, not related to ACL implementation.

To change where the outside DNS records are hosted, the network administrator needs to update the NS (Name Server) records at the domain registrar. NS records specify the authoritative name servers for a domain, directing where DNS queries should be sent.

NS (Name Server) Records: These records indicate the servers that are authoritative for a domain. Changing the NS records at the registrar points DNS resolution to the new hosting provider.

SOA (Start of Authority): Contains administrative information about the domain, including the primary name server.

PTR (Pointer) Records: Used for reverse DNS lookups, mapping IP addresses to domain names.

CNAME (Canonical Name) Records: Used to alias one domain name to another, not relevant for changing DNS hosting.

Network References:

CompTIA Network+ N10-007 Official Certification Guide: Discusses DNS records, their purposes, and how to manage them.

Cisco Networking Academy: Provides training on DNS management and the role of different DNS record types.

Network+ Certification All-in-One Exam Guide: Explains DNS records and their configuration for domain management.

A full-tunnel VPN routes all of a user ' s network traffic through the corporate network. This means that the organization can inspect all network traffic for security and compliance purposes, as all data is tunneled through the VPN, allowing for comprehensive monitoring and inspection.References: CompTIA Network+ study materials.

Switch 1

spanning-tree vlan 10 root primary

spanning-tree vlan 20 root secondary

Switch 2

spanning-tree vlan 20 root primary

spanning-tree vlan 10 root secondary

This PBQ is pointing to a switching loop / MAC flapping problem. The biggest clues are the high CPU utilization and the fact that the MAC table is continuously changing. That behavior is classic for a Layer 2 loop when redundant links exist between switches and no proper spanning-tree root role has been established.

The available commands shown in the screenshots are limited to spanning-tree vlan, so this is not an interface shutdown question. The fix is to use STP per VLAN and make one switch the preferred root for one VLAN and the other switch the preferred root for the other VLAN. That prevents both uplinks from forwarding in an uncontrolled loop while still giving redundancy.

A clean design is:

Switch 1 root primary for VLAN 10

Switch 2 root primary for VLAN 20

Make each opposite switch root secondary for failover

That stabilizes Layer 2 forwarding, stops MAC address flapping, reduces CPU load, and restores normal connectivity. After applying the STP root settings, the user should be able to ping 192.168.1.31 from PC 1 successfully. If your simulator asks for validation, run the ping again from PC 1 to the database server.

The user’s inability to access the marketing department’s shared drives, despite having internet access, suggests a network segmentation issue. The most likely cause is an incorrect VLAN assignment. The computer is physically located on the accounting department floor, and the switchport is likely configured for the accounting VLAN, not the marketing VLAN. VLANs segment network traffic, and if the computer is in the wrong VLAN, it cannot communicate with the marketing department’s resources.

Why not Mismatched switchport duplex? Duplex mismatches cause performance issues (e.g., packet loss) but not specific access denials to shared drives.

Why not Misconfigured gateway settings? Incorrect gateway settings would prevent internet access, which the user has.

Why not SVI is assigned to the wrong IP address? A Switch Virtual Interface (SVI) with an incorrect IP address affects inter-VLAN routing, but this would likely impact multiple users, not just one.

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. An IPS needs to be installed in line with traffic and an IDS does not. ✅ Correct answer. IPS actively prevents threats, while IDS only detects them.

B. An IPS is signature-based and an IDS is not. – False, both can use signature-based detection.

C. An IPS is less susceptible to false positives than an IDS. – False, both can produce false positives, depending on configurations.

D. An IPS requires less administrative overhead than an IDS. – False, IPS requires more administrative effort due to real-time blocking decisions.

The longest prefix match is a routing concept used to find the most specific route to a destination IP address. The routing table performs this calculation to determine the exit interface for a packet, ensuring the most accurate delivery. The document explains:

“Routers use the longest prefix match when searching the routing table to determine the best path for an IP packet. This ensures that the most specific (and thus optimal) route is chosen, based on the destination IP address.”

In Windows-based environments, Server Message Block, or SMB, is the primary protocol used for file sharing, printer sharing, and access to network shares. SMB commonly uses TCP port 445 for direct hosting over TCP/IP. Therefore, the correct answers are SMB and port 445. This matches the CompTIA Network+ N10-009 objectives related to common networking protocols, ports, and their purposes.

Port 21 is associated with FTP, which is used for file transfer but is not the standard protocol for Windows network shares. Port 443 is used by HTTPS, which secures web traffic using TLS. HTTPS can be used for web-based file access portals, but it is not the normal protocol used by Windows clients to access shared folders such as \\server\share. SMB specifically supports Windows file sharing functions, including authentication, permissions, folder browsing, and file transfer across a local network. Because SMB relies on TCP port 445 in modern Windows networks, the best two answers are C and E.

Network segmentation involves dividing a network into smaller segments or subnets. This is particularly important when integrating OT (Operational Technology) devices to ensure that these devices are isolated from other parts of the network. Segmentation helps protect the OT devices from potential threats and minimizes the impact of any security incidents. It also helps manage traffic and improves overall network performance.References: CompTIA Network+ study materials.

The CompTIA Troubleshooting Methodology states that after testing the theory, the next step is to establish a plan of action to resolve the issue.

Troubleshooting Steps:

Identify the problem.

Establish a theory of probable cause.

Test the theory to determine the cause.

Establish a plan of action and implement the solution. ✅ (Correct step)

Verify full system functionality.

Document findings, actions, and outcomes.

Breakdown of Options:

A. Verify full system functionality – Happens after implementing the solution.

B. Document the findings and outcomes – Final step, happens after resolving the issue.

C. Establish a plan of action – ✅ Correct answer. Comes immediately after confirming the cause.

D. Identify the problem – First step, already completed.