10 free CompTIA Network+ N10-009 practice questions with the correct answer and a full explanation for each, taken from the CertStash pack of 769 questions. Work through them, then open each answer to check your reasoning.
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Question 1
Which of the following steps of the troubleshooting methodology would most likely include checking through each level of the OSI model after the problem has been identified?
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Correct answer: A. Establish a theory.
After identifying the problem, the next step in the CompTIA troubleshooting methodology is to establish a theory of probable cause, which often involves questioning the obvious and systematically examining each layer of the OSI model to isolate where in the network stack (physical, data link, network, transport, session, presentation, application) the fault may lie. This structured approach helps technicians narrow down potential causes before testing the theory, making it the step most closely associated with methodically reviewing OSI layers.
Why the other options are wrong
- B. Implementing the solution occurs after the cause has been confirmed and a plan devised, not during initial cause analysis.
- C. Creating a plan of action happens after the theory has been tested and confirmed, focused on how to resolve the issue rather than diagnosing it.
- D. Verifying functionality is the final step to confirm the fix works and involves testing the whole system, not layer-by-layer diagnosis of cause.
Question 2
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?
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Correct answer: A. LLDP
LLDP (Link Layer Discovery Protocol) allows devices to discover and identify neighboring network devices and the switch ports they are connected to. This is the standard protocol for determining switch identity and port information without requiring manual configuration or network access.
Why the other options are wrong
- B. IKE (Internet Key Exchange) is related to VPN encryption, not device/port discovery.
- C. VLAN configuration helps segment networks but doesn't identify which physical switch port a device connects to.
- D. netstat displays network connections and statistics from the local device, not switch port information.
Question 3
A network administrator needs to set up a file server to allow user access. The organization uses DHCP to assign IP addresses.
Which of the following is the best solution for the administrator to set up?
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Correct answer: B. A reservation for the server based on the MAC address
address A DHCP reservation binds a specific MAC address to a fixed IP address, ensuring the file server always receives the same IP while remaining under DHCP management. This provides the reliability needed for a server that must be consistently addressable while maintaining DHCP infrastructure benefits.
Why the other options are wrong
- A. A /32 subnet is a single host and creates unnecessary complexity; reservations are simpler.
- C. Assigning a static IP within the DHCP range can cause conflicts if DHCP also assigns that address.
- D. SLAAC (Stateless Address Auto-Configuration) is for IPv6 and doesn't provide the centralized control needed for server management.
Question 4
Which of the following technologies are X.509 certificates most commonly associated with?
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Correct answer: A. PKI
X.509 certificates are the standard certificate format used within Public Key Infrastructure (PKI) systems for digital authentication, encryption, and identity verification. PKI is the framework that manages, distributes, and validates X.509 certificates.
Why the other options are wrong
- B. VLAN tagging is for network segmentation, unrelated to certificate technology.
- C. While LDAP can work with certificates, X.509 is most fundamentally associated with PKI, not LDAP specifically.
- D. MFA uses various authentication factors but X.509 certificates are not its primary association.
Question 5
A network administrator wants to implement an authentication process for temporary access to an organization's network.
Which of the following technologies would facilitate this process?
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Correct answer: A. Captive portal
A captive portal is specifically designed to provide temporary, guest-level network access by presenting an authentication page that users must complete before accessing the network. This is the standard technology for temporary access scenarios.
Why the other options are wrong
- B. Enterprise authentication is designed for permanent organizational users, not temporary access.
- C. Ad hoc networks are peer-to-peer connections, not suitable for centralized temporary access control.
- D. WPA3 is a wireless encryption standard, not an authentication/access control technology for temporary users.
Question 6
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?
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Correct answer: A. Hosts file
A hosts file on the user's local machine can override DNS resolution for specific URLs, causing them to resolve to incorrect IP addresses or not resolve properly while other users are unaffected. This explains why only one user has the issue; it's a local configuration problem rather than a network-wide DNS problem.
Why the other options are wrong
- B. Self-signed certificates cause security warnings, not URL resolution failures.
- C. Nameserver record issues would affect all users trying to reach the site, not just one user.
- D. IP helper is used for DHCP relay, not for DNS resolution issues.
Question 7
A network administrator is planning to host a company application in the cloud, making the application available for all internal and third-party users.
Which of the following concepts describes this arrangement?
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Correct answer: A. Multitenancy
Multitenancy describes a cloud architecture in which a single instance of an application, platform, or infrastructure serves multiple distinct users, groups, or organizations (tenants) while keeping their data and configurations logically separated. Hosting a company application in the cloud so that it is accessible to both internal employees and external third-party users reflects this shared-resource model, where the underlying infrastructure is common but access is extended to multiple types of consumers. This concept underpins most public and hybrid cloud offerings, allowing providers or organizations to efficiently serve a diverse user base without deploying separate dedicated environments for each group.
Why the other options are wrong
- B. A VPC refers to an isolated virtual network segment within a cloud provider's infrastructure, not the concept of serving multiple types of users from a shared application.
- C. NFV refers to virtualizing network functions like routers and firewalls in software, which is unrelated to the scenario of exposing an application to internal and third-party users.
- D. SaaS describes a cloud service delivery model where software is provided over the internet, but it does not specifically describe the arrangement of shared access among multiple user groups.
Question 8
Which of the following should be used to obtain remote access to a network appliance that has failed to start up properly?
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Correct answer: D. Out-of-band management
Out-of-band management provides remote access to network devices through a separate, independent management channel (such as serial console, IPMI, or dedicated management port) that remains accessible even when the main system has failed. This is essential for recovering devices that won't start normally.
Why the other options are wrong
- A. A crash cart is physical equipment for on-site access, not remote access.
- B. A jump box is for accessing secured networks, not for direct device recovery during startup failures.
- C. SSH requires the device to be fully operational, which won't work for a device that failed to start properly.
Question 9
Which of the following attacks utilizes a network packet that contains multiple network tags?
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Correct answer: B. VLAN hopping
VLAN hopping attacks exploit multiple network tags (double tagging) within a single packet. An attacker inserts an additional 802.1Q tag into a frame, allowing the packet to traverse multiple VLANs and reach restricted network segments. This technique specifically leverages the presence of multiple VLAN tags in a packet structure.
Why the other options are wrong
- A. MAC flooding attacks overwhelm the CAM table with numerous MAC addresses, not involving multiple network tags.
- C. DNS spoofing involves forging DNS responses to redirect users, unrelated to network packet tagging.
- D. ARP poisoning uses fraudulent ARP messages to map IP addresses to incorrect MAC addresses, not involving VLAN tags.
Question 10
A network administrator is configuring a new switch and wants to connect two ports to the core switch to ensure redundancy.
Which of the following configurations would meet this requirement?
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Correct answer: D. Link aggregation
Link aggregation, also called EtherChannel or bonding, joins the two ports into a single logical link with more bandwidth and built-in redundancy. If one member fails, traffic keeps flowing over the other, so the connection to the core switch stays up.
Why the other options are wrong
- A. Full duplex is a communication mode, not a redundancy mechanism.
- B. 802.1Q tagging identifies VLANs and does not provide port redundancy.
- C. A native VLAN carries untagged traffic on a trunk and adds no redundancy.
That was 10 of 769.
The full CompTIA Network+ N10-009 pack has all 769 questions, each with the answer, the explanation and why the other options are wrong, plus a questions-only copy for timed runs. US$39, paid once, with free monthly updates and a pass-or-your-money-back guarantee.