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

Single sign-on, or SSO, allows a user to access multiple applications, systems, or websites using one set of credentials. With SSO, the user authenticates once through an identity provider, and that authentication can then be trusted by multiple service providers. This improves user convenience, reduces password fatigue, and allows organizations to centralize authentication policies.

The CompTIA Network+ N10-009 objectives include authentication methods, identity and access management, and security concepts. SSO is commonly implemented using protocols or standards such as SAML, OAuth, or OpenID Connect, but SSO is the overall concept being described in the question.

SAML is a protocol often used for browser-based federated authentication, especially in enterprise environments. OpenID Connect is an authentication layer built on OAuth 2.0 and is also commonly used for federated login. However, both are implementation methods rather than the general capability described. A one-time password is a temporary authentication code, often used as part of multifactor authentication, but it does not by itself allow access to multiple websites using one credential set. Therefore, SSO is the correct answer.

Infrastructure as a Service (IaaS) provides scalable compute power, storage, and networking resources on demand. It is the best choice for a company that needs to customize its cloud solution based on size, compute capacity, and storage needs.

IaaS Benefits:

Provides virtual machines, storage, and networking resources.

Scalable based on company needs.

Reduces the need for physical infrastructure.

Incorrect Options:

A. SaaS (Software as a Service): Delivers software applications (e.g., Google Docs, Microsoft 365) but does not provide compute/storage infrastructure.

B. PaaS (Platform as a Service): Provides a development environment for application deployment but not full infrastructure control.

D. IaC (Infrastructure as Code): A methodology for automating infrastructure, not a cloud deployment model.

An out-of-band management solution is the best answer because it provides an alternate administrative path to network equipment when the normal production network path is unavailable. If a switch becomes unresponsive through SSH, the technician needs a separate management method that does not depend on the same in-band network connectivity. Out-of-band management can use a dedicated management network, console server, cellular connection, modem, or management interface to reach devices during outages or configuration failures.

The CompTIA Network+ N10-009 objectives include network operations, device management, availability, and remote access methods. SSH is an in-band management method when accessed over the production network. If routing, VLANs, ACLs, management services, or switch control-plane functions are affected, SSH may fail. Out-of-band access improves administrative redundancy and supports recovery.

A jump host can centralize administrative access, but it still depends on network connectivity to the switch. An administrative GUI may also fail if management access is unavailable. A physical console cable can work locally, but the question specifically asks for remote administrative redundancy. Therefore, an out-of-band management solution is the best answer.

A = 192.168.10.0/26

B = 192.168.1.0/23

C = 10.0.0.1/18

Using the choices shown in the screenshot, the best-fit subnet selections are based on host growth requirements first, then segmentation.

For Company A, the current device count is 32. With 20% growth, that becomes about 39 devices. A /27 only supports 30 usable hosts, so it is too small. A /26 supports 62 usable hosts, so 192.168.10.0/26 is the correct choice.

For Company B, the current device count is 100. With 20% growth, that becomes 120 devices. The smallest correct subnet would normally be a /25 with 126 usable hosts, but that option is not shown. From the available choices, 192.168.1.0/23 is the smallest subnet that still supports more than 120 hosts, so that is the best answer.

For Company C, the current device count is 10,000. With 20% growth, it needs space for 12,000 hosts. A /18 provides 16,382 usable hosts, while a /19 is not available and a /21 or /22 would be far too small. Therefore, 10.0.0.1/18 is the correct selection.

One important note: the dropdown choices shown do not actually let all three companies be placed into a single true Class B network block. So these answers are the best valid selections from the provided options.

802.1X is a port-based Network Access Control (NAC) method that enforces authentication before allowing access to the network. It uses a RADIUS server for identity verification and policy enforcement, ensuring only authorized users/devices gain access.

A. Standard ACL filters traffic by IP, not identity.

B. MAC filtering controls devices by hardware address but can be spoofed.

D. SSO (Single Sign-On) provides user convenience across services, not network-level access control.

References (CompTIA Network+ N10-009):

Domain: Network Security — NAC, 802.1X authentication, identity-based access.

The correct answer is B. NAT64. This scenario says the internal network is using only IPv6. In the real world, many internet services still rely on IPv4, so an IPv6-only client may need a translation mechanism to reach IPv4-based servers. That is exactly where NAT64 is used. It allows communication between IPv6-only clients and IPv4 resources by translating between the two protocols.

The other options do not solve that requirement. MPLS is used for traffic forwarding across provider networks and has nothing to do with IPv4/IPv6 protocol translation. GRE creates tunnels, but it does not automatically translate one IP version into another. Static routing can direct traffic, but it cannot make IPv6-only hosts speak to IPv4-only internet destinations.

From a Network+ perspective, this question is testing knowledge of IPv6 transition and interoperability mechanisms. If the network is entirely IPv6 internally, but still needs access to parts of the internet that may be IPv4, some translation service has to exist at the boundary. Among the choices given, NAT64 is the only technology that fits that role. That is why B is the best answer.

A /25 subnet mask means 25 bits are reserved for the network portion, leaving 7 bits for host addresses. In dotted decimal, that is:

11111111.11111111.11111111.10000000

Decimal equivalent: 255.255.255.128

A. 255.255.254.0 corresponds to /23.

B. 255.255.255.1 is invalid as a subnet mask.

D. 255.255.255.192 corresponds to /26.

Thus, the correct subnet mask for a /25 network is 255.255.255.128.

References (CompTIA Network+ N10-009):

Domain: Networking Concepts — Subnetting, CIDR notation, dotted decimal.

Understanding Tracert:

tracert (Traceroute in Windows) is a command-line tool used to trace the path that packets take from the source to the destination. It records the route (the specific gateways at each hop) and measures transit delays of packets across an IP network.

Output Analysis:

The output shows a series of IP addresses with corresponding round-trip times (RTTs) in milliseconds.

The asterisks (*) indicate that no response was received from those hops, which is typical for routers or firewalls that block ICMP packets used by tracert.

Comparison with Other Tools:

netstat: Displays network connections, routing tables, interface statistics, and more, but does not trace packet routes.

tcpdump: Captures network packets for analysis, used for detailed network traffic inspection.

nmap: A network scanning tool used to discover hosts and services on a network, not for tracing packet routes.

Usage:

tracert helps identify the path to a destination and locate points of failure or congestion in the network.

The correct answer is Full-tunnel because the policy requires all network traffic from remote corporate laptops to pass through the company’s VPN. In a full-tunnel VPN configuration, once the VPN connection is established, all traffic—including internet-bound traffic—is routed through the corporate network before reaching its destination. This ensures centralized monitoring, content filtering, logging, and enforcement of security controls such as IDS/IPS and firewalls.

According to CompTIA Network+ (N10-009) security objectives, full-tunnel VPNs enhance security by preventing users from directly accessing the internet from their local connection, thereby reducing exposure to local network threats (e.g., public Wi-Fi attacks).

A split-tunnel VPN (Option D) allows users to access the internet directly while only sending corporate-bound traffic through the VPN, which does not meet the “all traffic” requirement. A site-to-site tunnel (Option C) connects entire networks rather than individual remote users. A clientless VPN (Option A) typically provides web-based access without a full network tunnel and does not necessarily route all traffic.

Therefore, full-tunnel best matches the policy requirement.

The correct answer is STP (Shielded Twisted Pair). According to the CompTIA Network+ N10-009 objectives, environments with high levels of electromagnetic interference (EMI)—such as industrial warehouses with heavy machinery, motors, and electrical equipment—require additional protection at the physical layer to maintain signal integrity.

STP cabling includes shielding around the twisted copper pairs that helps block external electromagnetic signals from interfering with data transmission. This shielding significantly reduces crosstalk and EMI, making STP far more suitable than UTP (Unshielded Twisted Pair) in electrically noisy environments. UTP lacks this shielding and is more prone to signal degradation under such conditions.

While fiber-optic cabling (multimode or single-mode) is completely immune to EMI, it is typically not used to directly connect wireless APs in most enterprise deployments. Wireless access points commonly rely on copper Ethernet connections to support Power over Ethernet (PoE), which supplies both data and electrical power over the same cable. Fiber does not natively support PoE, making it impractical for directly powering APs without additional equipment.

The Network+ objectives emphasize selecting appropriate cabling based on environmental factors and operational requirements. In this scenario, STP provides the optimal balance of EMI resistance, Ethernet compatibility, and PoE support, making it the best choice for connecting APs in an industrial warehouse.

Quality of Service, or QoS, is used when implementing VoIP phones because voice traffic is sensitive to delay, jitter, and packet loss. QoS allows network administrators to classify and prioritize traffic so that real-time voice packets receive preferential treatment over less time-sensitive traffic such as file downloads, backups, or general web browsing. This helps maintain call quality, reduce dropped audio, and improve the user experience during periods of network congestion.

The CompTIA Network+ N10-009 objectives include traffic management, network performance, and services that require prioritization. VoIP is one of the most common examples of a service that benefits from QoS because voice communication must be delivered consistently and in sequence.

A VPN provides secure encrypted connectivity but does not inherently prioritize voice traffic. A CDN distributes content closer to users, typically for web or media delivery, and is not specifically used to implement VoIP phones. TTL, or Time to Live, is a packet field that helps prevent packets from circulating indefinitely in a network. Therefore, QoS is the correct answer for VoIP implementation.

To confirm a theory in the troubleshooting process, the technician should duplicate (replicate) the problem under controlled conditions. In the Network+ (N10-009) methodology, confirming a theory means validating that the suspected cause actually produces the observed symptoms. Replicating the issue helps ensure the technician is not chasing a coincidence, and it allows changes to be tested safely (for example, reproducing the issue with a specific user account, endpoint, cable, port, SSID, or configuration). If the problem can be duplicated, the technician can then try targeted actions to see whether the symptoms change in predictable ways—strengthening or disproving the hypothesis.

The other choices occur earlier as part of forming the theory. Identify the symptoms is an initial step to define the problem clearly. Gather information is part of the discovery phase—collect logs, error messages, topology details, and user observations. Determine any changes is also an early step used to correlate recent modifications (patches, new devices, config changes) with the onset of the issue. Those steps help create a theory; duplication helps confirm it before implementing a full fix.

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The answer is C. Multicast. The address 224.7.8.99 falls within the IPv4 Class D range, which is 224.0.0.0 through 239.255.255.255. That range is reserved for multicast traffic. Multicast is used when one sender needs to deliver traffic to a specific group of receivers rather than to every device on the network or to just one destination.

That is what separates it from the other choices. Broadcast is intended for all hosts on the local broadcast domain. Unicast is one-to-one communication, where a single source sends traffic to one specific destination. Anycast is typically associated with sending traffic to the nearest or best member of a group that shares the same address, not to a multicast group address in the 224.0.0.0/4 range.

From a Network+ point of view, this is a basic address-recognition question. Once you recognize that the destination begins with 224, the answer should immediately point to multicast. Protocols and streaming applications often use multicast when they need efficient delivery to multiple interested hosts without flooding every device. So in this case, the traffic type is clearly multicast.

The correct answer is PAT (Port Address Translation). According to the CompTIA Network+ N10-009 objectives, PAT is a form of Network Address Translation (NAT) that allows multiple internal hosts—or services—to be mapped to a single public IP address using different port numbers. PAT can also translate destination port numbers, which is exactly what is occurring in this scenario.

In this case, the firewall receives incoming traffic on port 80 (commonly used for HTTP) and forwards it to an internal server listening on port 88. This process is often referred to as port forwarding, which is a practical implementation of PAT. The firewall rewrites the destination port and potentially the destination IP address so that external clients can access internal services without exposing internal addressing schemes.

The other options do not apply. TLS and SSL are encryption protocols used to secure data in transit; they do not perform port translation. FHRP (First Hop Redundancy Protocol), such as HSRP or VRRP, provides gateway redundancy and high availability, not traffic forwarding or port remapping.

The Network+ objectives emphasize understanding how firewalls and NAT technologies manipulate IP addresses and ports to enable secure access to internal resources. PAT is the technology that enables this functionality, making it the correct answer.

If the business shares or duplicates the ISP-assigned public IP address, routing instability and conflicts will occur. Pinging a public IP like 8.8.8.8 may work (since ICMP can bypass certain conflicts), but browsing websites (which requires stable sessions and return traffic) will fail intermittently.

A. If the default gateway were incorrect, no external connectivity would work at all.

B. VLAN mismatch is an internal issue, not affecting ISP routing.

C. Subnet mask misconfiguration would prevent consistent routing but usually blocks ping too.

References (CompTIA Network+ N10-009):

Domain: Network Troubleshooting — Internet connectivity issues, ISP IP conflicts.

To determine where slowness is occurring—especially if an upstream router is suspected—the best tools are ping and tracert/traceroute. Network+ (N10-009) troubleshooting objectives emphasize using these to test connectivity, latency, and the path packets take through the network. Ping measures reachability and round-trip time; rising latency or packet loss can indicate congestion or a failing link/device. Tracert identifies each hop along the route and reports per-hop response times, helping pinpoint whether delays begin at a specific hop (for example, the default gateway, the upstream router, or a provider edge). This allows the engineer to localize the problem area and decide whether the issue is internal, at the upstream router, or beyond.

nslookup and dig are DNS tools; they diagnose name resolution, not general network slowness location. Nmap focuses on scanning ports/hosts, and a “speed tester” measures throughput but does not locate the failing hop. tcpdump and protocol analyzer can reveal retransmissions, windowing, or application behavior, but they are not the fastest first-choice tools for locating an upstream routing/performance bottleneck across hops. Hence, tracert and ping are the correct pair.

The correct answer is D. Administratively down. The question states that another technician had already turned off unused switchports as part of hardening. When a port is intentionally disabled by configuration, its status is described as administratively down. In other words, the switchport is not broken and has not failed on its own; it has simply been shut down by an administrator.

This is a common security practice. Unused ports are often disabled so unauthorized devices cannot be plugged in and gain access to the network. If a legitimate device later needs that port, the administrator must re-enable it before the link can come up.

The other answer choices do not line up as well with the scenario. Error disabled usually points to a protective shutdown caused by a violation or fault, such as port security or BPDU guard. Idle is not the standard description for a manually shut switchport in this context. Suspended can appear with certain switch features, but it is not the normal label for a port deliberately turned off as part of hardening.

The phrase “turned off unused switchports” is the key detail. That clearly indicates a manual administrative shutdown, so administratively down is the best answer.

API gateways offer programmable control and real-time communication, commonly over HTTPS, which allows administrators to update and manage devices like access points remotely and efficiently.

From Andrew Ramdayal’s guide:

“APIs enable automation and real-time interaction with network devices via secure interfaces, often using HTTPS for encrypted communication and control.”

A DoS (Denial of Service) attack directly targets availability, one of the core security goals (CIA triad) emphasized in Network+ (N10-009) security objectives. A web-based customer portal depends on reachable services (web servers, load balancers, DNS, upstream bandwidth). In a DoS, an attacker attempts to overwhelm the portal or its supporting infrastructure—consuming bandwidth, exhausting server resources, or saturating state tables—so legitimate users cannot connect or experience severe degradation. This is the most direct and common scenario where “availability” is impacted for a public web service.

MAC flooding aims to overflow a switch’s CAM table and can lead to traffic being broadcast out ports, which is more commonly associated with enabling sniffing or disruption within a local switched network segment—not typically the primary attack described for a web portal’s availability. ARP spoofing is a local network man-in-the-middle/redirection technique affecting integrity/confidentiality and potentially availability for local hosts, but it is not the best match for a public portal availability impact. Rogue devices can introduce risk, but the option is broad and indirect; DoS is the clearest availability-focused threat.

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The correct answer is Spanning Tree because broadcast storms are typically caused by Layer 2 switching loops in Ethernet networks. According to the CompTIA Network+ (N10-009) objectives under switching concepts, the Spanning Tree Protocol (STP) is specifically designed to prevent loops in networks that have redundant switch connections.

In a Layer 2 environment, switches forward broadcast frames out all ports except the one on which they were received. If redundant paths exist without STP, frames can circulate indefinitely, creating a broadcast storm. This results in excessive traffic, high CPU utilization on switches, MAC address table instability, and significant network performance degradation.

STP prevents this by logically blocking redundant paths while maintaining them as backups. If the active path fails, STP recalculates and activates a previously blocked path, preserving redundancy without loops.

The other options—EIGRP and BGP (routing protocols) and CDP and LLDP (device discovery protocols)—do not prevent Layer 2 loops.

Therefore, configuring Spanning Tree Protocol is the appropriate solution to mitigate broadcast storms.

The correct answer is B. MAC filtering. MAC filtering is a straightforward method of restricting network access by allowing only specific device MAC (Media Access Control) addresses to connect to a wireless network. In a small, stable environment with fewer than ten devices and no expected changes, this approach is simple to implement and manage.

Each network interface card (NIC) has a unique MAC address, and wireless access points can be configured with a whitelist of approved addresses. Devices not on the list are denied access, effectively limiting connectivity to only authorized laptops. This aligns with CompTIA Network+ guidance for basic access control mechanisms in small or low-complexity networks.

Other options are less suitable in this scenario. ACLs (Access Control Lists) are typically used on routers and switches to control traffic flow based on IP addresses or protocols, not specifically device access to a wireless network. NAC (Network Access Control) provides more advanced authentication and posture assessment but is more complex and unnecessary for a small, static environment. Trusted zones refer to network segmentation concepts rather than device-level access control.

Thus, MAC filtering provides the simplest and most appropriate solution.

Port security is a Layer 2 security feature that restricts the number of devices connecting to a network switch port. It helps prevent unauthorized devices, such as an unmanaged switch, from being connected to the network.

How Port Security Works:

Limits the number of MAC addresses that can connect to a port.

Can shut down or restrict the port if an unauthorized device is detected.

Prevents users from plugging in unauthorized networking equipment (e.g., unmanaged switches, hubs).

Incorrect Options:

A. Screened Subnet: A screened subnet (DMZ) is used for isolating external-facing servers, not for controlling unauthorized network connections.

B. 802.1X: Provides authentication for devices but requires a RADIUS server, which is a more complex solution than port security.

C. MAC Filtering: Controls which MAC addresses can connect but is difficult to manage and can be spoofed.

Servers shut down due to overheating, not loss of electrical power. Although UPS units had battery life, without cooling systems (HVAC/air conditioning) running on backup power, server rooms overheated. Backup power for air-conditioning is essential in data center design.

B. Door locks are unrelated to server shutdown.

C. Increasing UPS capacity won’t help cooling.

D. IoT thermostats may monitor temperature but won’t prevent overheating.

References (CompTIA Network+ N10-009):

Domain: Network Infrastructure — Environmental controls, power redundancy, HVAC systems.

A mesh network is the best solution for providing reliable wireless service to public safety vehicles. In a mesh network, each node (vehicle) can connect to multiple other nodes, providing multiple paths for data to travel. This enhances reliability and redundancy, ensuring continuous connectivity even if one or more nodes fail. Mesh networks are highly resilient and are well-suited for dynamic and mobile environments such as public safety operations.References: CompTIA Network+ study materials.

Configuration monitoring and management tools (often part of network management systems) maintain version-controlled records of device configurations, track changes, and log who made them. This provides accountability and supports compliance audits.

A. Network access control (NAC) manages endpoint access policies but does not track device config changes.

C. Zero Trust is a security framework requiring strict identity verification, not a configuration tracking tool.

D. Syslog collects system logs, but without a config monitoring system, it does not directly compare documentation to device state.

References (CompTIA Network+ N10-009):

Domain: Network Operations — Change management, configuration management, auditing.

802.1X provides port-based Network Access Control (NAC). Ports remain in a blocked state until a device authenticates (usually with RADIUS). This is ideal for public or semi-public areas where ports should not be “always on.”

A. Port security restricts by MAC addresses but does not authenticate users.

C. MAC filtering is easily spoofed and weaker than 802.1X.

D. ACLs filter traffic but do not enforce port-based authentication.

References (CompTIA Network+ N10-009):

Domain: Network Security — NAC, 802.1X authentication, port-based security.

The troubleshooting methodology requires following a logical sequence. In this case, the engineer has already identified the problem (firewall blocking traffic) and confirmed it with evidence (packet captures). The next appropriate step is to create a plan of action that outlines how to resolve the issue and considers potential effects.

A. Implementing the solution is premature without planning.

C. Establishing a theory was already completed during problem isolation.

D. Documentation occurs after resolution.

By carefully planning, the engineer ensures that corrective action won’t cause additional outages or security issues, especially given the scale of the incident (3,000 users).

References (CompTIA Network+ N10-009):

Domain: Network Troubleshooting — Troubleshooting methodology, plan of action.