Free Practice Questions for the CompTIA Network+ N10-009 Exam (2026 Updated)
At Marks4sure, we are dedicated to providing IT professionals with the most accurate and reliable preparation materials for the CompTIA N10-009 exam. To support your certification journey, we have made a selection of our premium 2026 CompTIA Network+ practice questions and answers available completely free. You can take this practice test as many times as you need. Every question includes a detailed, expertly verified explanation to ensure you fully grasp the core security concepts before test day.
A company recently experienced outages of one of its critical, customer-facing applications. The root cause was an overutilized network router, but the Chief Technology Officer is concerned that the support staff was unaware of the issue until notified by customers. Which of the following is the best way to address this issue in the future?
Which of the following steps in the troubleshooting methodology comes after using a top-to-top buttom examination of the OSI model to determine cause?
A company has observed increased user traffic to gambling websites and wants to limit this behavior on work computers. Which of the following should the company most likely implement?
Which of the following fiber connector types is the most likely to be used on a network interface card?
A network engineer needs to order cabling to connect two buildings within the same city. Which of the following media types should the network engineer use?
While troubleshooting connectivity issues, a junior network administrator is given explicit instructions to test the host’s TCP/IP stack first. Which of the following commands should the network administrator run?
A server administrator needs to add a record to the company ' s DNS server to verify ownership of a web domain. The administrator has the record ' s name and value. Which of the following record types should the administrator use to add the record to the DNS server?
Which of the following layers in the OSI model is responsible for establishing, maintaining, and terminating connections between nodes?
A network engineer is designing an internal network that needs to support both IPv4 and IPv6 routing. Which of the following routing protocols is capable of supporting both IPv4 and IPv6?
A user called the help desk after business hours to complain that files on a device are inaccessible and the wallpaper was changed. The network administrator thinks that this issue is an isolated incident, but the security analyst thinks the issue might be a ransomware attack. Which of the following troubleshooting steps should be taken first?
A network engineer needs to prioritize traffic over a link with the goal of more effectively utilizing the connection. Which of the following should the engineer implement?
A network engineer is installing new PoE wireless APs. The first five APs deploy successfully, but the sixth one fails to start. Which of the following should the engineer investigate first?
Network administrators are using the Telnet protocol to administer network devices that are on the 192.168.1.0/24 subnet. Which of the following tools should the administrator use to best identify the devices?
A network administrator performed upgrades on a server and installed a new NIC to improve performance. Following the upgrades, usera are unable to reach the server. Which of the following is the most likely reason.
Which of the following network cables involves bounding light off of protective cladding?
Which of the following is most commonly associated with many systems sharing one IP address in the public IP-addressing space?
A user calls the help desk after business hours to complain that files on a device are inaccessible and the wallpaper was changed. The network administrator thinks that this issue is an isolated incident, but the security analyst thinks the issue might be a ransomware attack. Which of the following troubleshooting steps should be taken first?
Company C is acquiring Company A and Company B. Company C needs to merge all
three networks into one Class B network. Additionally, the network capacity of each company needs to grow by 20%. Company C also requires segmentation of Company A and Company B to account for unknown security vulnerabilities within each.
Instructions:
Select the correct subnet range to meet Company C ' s requirements.
A network administrator needs to monitor data from recently installed firewalls in multiple locations. Which of the following solutions would best meet the administrator ' s needs?
A network administrator is responding to a request to configure a new IP phone. Which of the following should the network administrator do to allow data and voice traffic to be properly prioritized?
A support engineer is troubleshooting a network outage that is affecting 3,000 users. The engineer has isolated the issue to the internet firewall. Packet captures confirm that the firewall is blocking the traffic. Which of the following is the next step in troubleshooting?
A network administrator needs to change where the outside DNS records are hosted. Which of the following records should the administrator change the registrar to accomplish this task?
A company implements a new network utilizing only IPv6 addressing and needs to connect to the internet. Which of the following must be enabled in order for the internal network to contact servers on the internet?
Which of the following impacts the availability of a web-based customer portal?
Which of the following tools uses ICMP to help determine whether a network host is reachable?
Developers want to create a mobile application that requires a runtime environment, developer tools, and databases. The developers will not be responsible for security patches and updates. Which of the following models meets these requirements?
While deploying a new fleet of computers on a DHCP network, a network administrator notices that new computers cannot connect to the internet. Which of the following is most likely the problem?
Which of the following best describes a group of devices that is used to lure unsuspecting attackers and to study the attackers ' activities?
An IT manager needs to connect ten sites in a mesh network. Each needs to be secured with reduced provisioning time. Which of the following technologies will best meet this requirement?
A network administrator is planning to implement device monitoring to enhance network visibility. The security that the solution provides authentication and encryption. Which of the following meets these requirements?
A technician needs to identify a computer on the network that is reportedly downloading unauthorized content. Which of the following should the technician use?
Which of the following connection methods allows a network engineer to automate configuration deployment for network devices across the environment?
A network administrator is configuring a new switch and wants to ensure that only assigned devices can connect to the switch. Which of the following should the administrator do?
Users report performance issues on the network. A network administrator notices broadcast storms occurring. Which of the following protocols should the administrator configure to mitigate this issue?
A network administrator needs to divide 192.168.1.0/24 into two equal halves. Which of the following subnet masks should the administrator use?
Employees report that the network is slow. The network engineer thinks the performance issue is with an upstream router. Which of the following tools should the engineer use to determine the location of the issue?
A network engineer needs to deploy an access point at a remote office so that it will not communicate back to the wireless LAN controller. Which of the following deployment methods must the engineer use to accomplish this task?
An organization recently connected a new computer to the LAN. The user is unable to ping the default gateway. The technician examines the configuration and sees a self-assigned IP address. Which of the following is the most likely cause?
The leadership team is updated on the results of an approved change request after a breach. Which of the following troubleshooting methodology steps is described in this example?
A network technician needs to resolve some issues with a customer ' s SOHO network. The
customer reports that some of the PCs are not connecting to the network, while others
appear to be working as intended.
INSTRUCTIONS
Troubleshoot all the network components.
Review the cable test results first, then diagnose by clicking on the appropriate PC,
server, and Layer 2 switch.
Identify any components with a problem and recommend a solution to correct each
problem.
If at any time you would like to bring back
the initial state of the simulation, please
click the Reset All button.
A technician is implementing a new SD-WAN device with a default configuration. The technician receives a URL via email and connects the new device to the internet to complete the installation. Which of the following is this an example of?
A network administrator suspects users are being sent to malware sites that are posing as legitimate sites. The network administrator investigates and discovers that user workstations are configured with incorrect DNS IP addresses. Which of the following should the network administrator implement to prevent this from happening again?
Users cannot connect to an internal website with an IP address 10.249.3.76. A network administrator runs a command and receives the following output:
1 3ms 2ms 3ms 192.168.25.234
2 2ms 3ms 1ms 192.168.3.100
3 4ms 5ms 2ms 10.249.3.1
4 *
5 ’
6 *
7 •
Which of the following command-line tools is the network administrator using?
After a recent security awareness phishing campaign, the cybersecurity team discovers that additional security measures need to be set up when users access potentially malicious websites. Which of the following security measures will best address this concern?
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?
Which of the following should be used to obtain remote access to a network appliance that has failed to start up properly?
A company wants to implement data loss prevention by restricting user access to social media platforms and personal cloud storage on workstations. Which of the following types of filtering should the company deploy to achieve these goals?
A network technician is troubleshooting network latency and has determined the issue to be occuring two network switches( Switch10 and Switch11). Symptoms reported included poor video performance and slow file copying. Given the following informtion:
Which of the following should the technician most likely do to resolve the issue?
Which of the following provides simple authentication to access network devices while also providing logging capabilities?
A technician is planning an equipement installation into a rack in a data center that practices hot aisle/cold aise ventilation. Which of the following directions should the equipement exhaust face when installed in the rack?
Which of the following types of routes takes precedence when building a routing table for a given subnet?
A wireless technician wants to implement a technology that will allow user devices to automatically navigate to the best available frequency standard. Which of the following technologies should the technician use?
A Chief Executive Officer (CEO) of a company purchases a new phone that will be used while traveling to different countries. The CEO needs to be able to place outgoing calls and receive incoming calls on the phone using a SIM card. Which of the following cellular technologies does the CEO ' s phone need?
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). Which of the following classful IPv4 address ranges will be best-suited for the network?
A company receives a cease-and-desist order from its ISP regarding prohibited torrent activity. Which of the following should be implemented to comply with the cease-and-desist order?
A network administrator receives a ticket from a user. The user reports that they cannot access any websites and that they have already checked everything on their computer. Which of the following is the first action the administrator should take?
A company’s Chief Information Security Officer requires that servers and firewalls have accurate timestamps when creating log files so that security analysts can correlate events during incident investigations. Which of the following should be implemented?
A network technician is working on a PC with a faulty NIC. The host is connected to a switch with secured ports. After testing the connection cables and using a known-good NIC, the host is still unable to connect to the network. Which of the following is causing the connection issue?
A network engineer performed a migration to a new mail server. The engineer changed the MX record, verified the change was accurate, and confirmed the new mail server was reachable via the IP address in the A record. However, users are not receiving email. Which of the following should the engineer have done to prevent the issue from occurring?
A network technician is attempting to harden a commercial switch that was recently purchased. Which of the following hardening techniques best mitigates the use of publicly available information?
A company is migrating a data center from on premises to the cloud. Which of the following tools will help maintain consistency, reliability, and efficiency of provisioning and management?
Which of the following concepts describes the idea of housing different customers in the same public cloud data center?
Which of the following steps of the troubleshooting methodology should a technician take to confirm a theory?
Which of the following explains what happens if a packet is lost in transit when using UDP?
Which of the following kinds of targeted attacks uses multiple computers or bots to request the same resource repeatedly?
After extremely high temperatures cause a power outage, the servers automatically shut down, even though the UPSs for the servers still have hours of battery life. Which of the following should a technician recommend?
A user notifies a network administrator about losing access to a remote file server. The network administrator is able to ping the server and verifies the current firewall rules do not block access to the network fileshare. Which of the following tools wold help identify which ports are open on the remote file server?
Which of the following uses the longest prefix match to determine an exit interface?
A network administrator manages multiple computers and notices that three computers are no longer communicating with the network. Which of the following commands best identifies whether other devices are restricting packet traffic?
A user ' s home mesh wireless network is experiencing latency issues. A technician has:
•Performed a speed test.
•Rebooted the devices.
•Performed a site survey.
•Performed a wireless packet capture.
The technician reviews the following information:
The technician notices in the packet capture that frames were retransmitted. Which of the following is the most likely cause of the user ' s network issue?
Which of the following Layer 1 devices is responsible for the termination of fiber-optic connections on an SFP-capable switch?
A network administrator is reviewing a production web server and observes the following output from the netstat command:
Which of the following actions should the network administrator take to harden the security of the web server?
Which of the following OSI model layers manages the exchange of HTTP information?
SIMULATION
You have been tasked with setting up a wireless network in an office. The network will consist of 3 Access Points and a single switch. The network must meet the following parameters:
The SSIDs need to be configured as CorpNet with a key of S3cr3t!
The wireless signals should not interfere with each other
The subnet the Access Points and switch are on should only support 30 devices maximum
The Access Points should be configured to only support TKIP clients at a maximum speed
INSTRUCTONS
Click on the wireless devices and review their information and adjust the settings of the access points to meet the given requirements.
If at any time you would like to bring back the initial state of the simulation, please click the Reset All button.
A network administrator is setting up two new firewalls for redundancy and needs to implement a redundant internet connection. Which of the following routing technologies will the administrator most likely use?
A network administrator needs to configure the core switches where multiple connections between data centers are used. Given the following requirements:
• Fault tolerance and redundancy
• Vendor interoperability
• Increased bandwidth
• Cost effectiveness
• Simplified management
Which of the following should the administrator configure?
A media company is implementing a global streaming service. Which of the following should the company apply to each regional point of presence in order to comply with local laws?
As part of a recovery strategy, a network administrator needs to make sure no more than eight hours of data loss occurs. Which of the following DR metrics describes this requirement?
Which of the following steps of the troubleshooting methodology comes after testing the theory to determine cause?
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 network administrator is developing a method of device monitoring with the following requirements:
•Allows for explicit, by user, privilege management
•Includes centralized logging of changes
•Offers widely accessible remote management
•Provides support of service accounts
Which of the following will most closely meet these requirements?
Following a fire in a data center, the cabling was replaced. Soon after, an administrator notices network issues. Which of the following are the most likely causes of the network issues? (Select two).
A network administrator is implementing security zones for each department. Which of the following should the administrator use to accomplish this task?
A systems administrator is configuring a new device to be added to the network. The administrator is planning to perform device hardening prior to connecting the device. Which of the following should the administrator do first?
Which of the following routing protocols needs to have an autonomous system set in order to establish communication with neighbor devices?
Which of the following routing technologies allows all users to access the internet using only two public IPs?
Which of the following requires network devices to be managed using a different set of IP addresses?
Which of the following is the best VPN to use for reducing data bandwidth requirements of the corporate network?
A company is opening a new site that needs to be divided into subnets that accommodate 75 hosts each. Which of the following is the most efficient subnet?
A network administrator needs to connect a multimode fiber cable from the MDF to the server room. The administrator connects the cable to Switch 2, but there is no link light. The administrator tests the fiber and finds it does not have any issues. Swapping the connection to Switch 1 in a working port is successful, but the swapped connection does not work on Switch 2. Which of the following should the administrator verify next?
A network administrator is setting up a firewall to protect the organization’s network from external threats. Which of the following should the administrator consider first when configuring the firewall?
While troubleshooting connectivity issues, a junior network administrator is given explicit instructions to test the host ' s TCP/IP stack first. Which of the following commands should the network administrator run?
Which of the following protocol ports should be used to securely transfer a file?
A newly opened retail shop uses a combination of new tablets, PCs, printers, and legacy card readers. Which of the following wireless encryption types is the most secure and compatible?
Which of the following devices functions mainly at the data link layer of the OSI model and is used to connect a fiber-optic cable to a network interface?
A network engineer configures a new switch and connects it to an existing switch for expansion and redundancy. Users immediately lose connectivity to the network. The network engineer notes the following spanning tree information from both switches:
Switch 1
Port State Cost
1 Forward 2
2 Forward 2
Switch 2
Port State Cost
1 Forward 2
2 Forward 2
Which of the following best describes the issue?
A company security policy requires all network traffic from remote employees ' corporate laptops to use the company’s VPN. Which of the following network access methods best describes this scenario?
Which of the following is the best way to securely access a network appliance from an external location?
A network technician needs to install patch cords from the UTP patch panel to the access switch for a newly occupied set of offices. The patch panel is not labeled for easy jack identification. Which of the following tools provides the easiest way to identify the appropriate patch panel port?
Users are unable to access files on their department share located on file server 2.
The network administrator has been tasked with validating routing between networks
hosting workstation A and file server 2.
INSTRUCTIONS
Click on each router to review output, identify any issues, and configure the appropriate solution.
If at any time you would like to bring back the initial state of the simulation, please click the Reset All button.
An administrator is troubleshooting a Layer 3 communication issue between the web server and the database server. The administrator finds the following information:
Device
IP
Subnet
Gateway
Firewall
192.168.1.1
255.255.255.0
1.2.3.4
Web server
192.168.1.50
255.255.255.0
192.168.1.1
Database server
192.168.1.201
255.255.255.128
192.168.1.1
Which of the following corrects the communication issue?
As part of an attack, a threat actor purposefully overflows the content-addressable memory (CAM) table on a switch. Which of the following types of attacks is this scenario an example of?
Two companies successfully merged. Following the merger, a network administrator identified a connection bottleneck. The newly formed company plans to acquire a high-end 40GB switch and redesign the network from a three-tier model to a collapsed core. Which of the following should the administrator do until the new devices are acquired?
A systems administrator is investigating why users cannot reach a Linux web server with a browser but can ping the server IP. The server is online, the web server process is running, and the link to the switch is up. Which of the following commands should the administrator run on the server first?
Several users in an organization report connectivity issues and lag during a video meeting. The network administrator performs a tcpdump and observes increased retransmissions for other non-video applications on the network. Which of the following symptoms describes the users ' reported issues?
During a VoIP call, a user notices inconsistent audio and logs an incident ticket. A network administrator notices inconsistent delays in arrival of the RTP packets. Which of the following troubleshooting tools should the network administrator use to determine the issue?
Which of the following terms describes the capability in a public cloud to add or remove compute resources based on need?
Which of the following is the most likely benefit of installing server equipment in a rack?
An IT department is considering implementing a SIEM solution to improve network security. The department wants to ensure that the SIEM system is able to ingest and analyze logs from all of the company’s core devices. Which of the following is the most important consideration when selecting a SIEM solution?
A company is upgrading its wireless network. Currently, each AP broadcasts a wireless LAN name depending on the location in the building. Which of the following configurations allows a single wireless LAN name to be broadcast across the entire building?
A network administrator wants to configure a backup route in case the primary route fails. A dynamic routing protocol is not installed on the router. Which of the following routing features should the administrator choose to accomplish this task?
Which of the following is the greatest advantage of maintaining a cold DR site compared to other DR sites?
Users report that they cannot print to a specific IPv4-enabled printer after an extended power outage. Which of the following should a technician configure?
A virtual machine has the following configuration:
•IPv4 address: 169.254.10.10
•Subnet mask: 255.255.0.0
The virtual machine can reach colocated systems but cannot reach external addresses on the Internet. Which of the following Is most likely the root cause?
A network administrator needs to deploy a subnet using an IP address range that can support at least 260 devices with the fewest wasted addresses. Which of the following subnets should the administrator use?
Which of the following attacks utilizes a network packet that contains multiple network tags?
Which of the following routing protocols is most commonly used to interconnect WANs?
A network engineer added more APs to improve wireless coverage. However, users now report that the connectivity disconnects and reconnects repeatedly. Which of the following is causing the issue?
A network administrator needs to fail over services to an off-site environment. This process will take four weeks to become fully operational. Which of the following DR (Disaster Recovery) concepts does this describe?
Which of the following ports should a network administrator enable for encrypted login to a network switch?
A junior network administrator gets a text message from a number posing as the domain registrar of the firm. The administrator is tricked into providing global administrator credentials. Which of the following attacks is taking place?
Which of the following is the best networking appliance for interconnecting multiple logical networks and forwarding data packets between them while minimizing latency?
A network administrator needs to locate a specific AP using a spectrum analyzer to complete an 802.11ax device migration. Which of the following should display on the analyzer to locate the AP?
A network engineer is deploying switches at a new remote office. The switches have been preconfigured with hostnames and STP priority values. Based on the following table:
Switch Name
Priority
core-sw01
24576
access-sw01
28672
distribution-sw01
32768
access-sw02
36864
Which of the following switches will become the root bridge?
A network rack has four servers and four switches with dual power supplies. Only one intelligent PDU is installed in the rack. Which of the following is the reason to add a second PDU?
A network administrator notices interference with industrial equipment in the 2.4GHz range. Which of the following technologies would most likely mitigate this issue? (Select two).
A network administrator recently configured an autonomous wireless AP and performed a throughput test via comptiaspeedtester.com. The result was 75 Mbps. When connected to other APs, the results reached 500 Mbps. Which of the following is most likely the reason for this difference?
A network technician is troubleshooting a web application ' s poor performance. The office has two internet links that share the traffic load. Which of the following tools should the technician use to determine which link is being used for the web application?
Which of the following allows a user to authenticate to multiple resources without requiring additional passwords?
A network administrator installs new cabling to connect new computers and access points. After deploying the equipment, the administrator notices a few of the devices are not connecting properly. The administrator moves the devices to a different port, but it does not resolve the issue. Which of the following should the administrator verify next?
Which of the following VPN types provides secure remote access to the network resources through a web portal?
A network administrator is deploying a new switch and wants to make sure that the default priority value was set for a spanning tree. Which of the following values would the network administrator expect to see?
Which of the following types of attacks is most likely to occur after an attacker sets up an evil twin?
Which of the following disaster recovery metrics is used to describe the amount of data that is lost since the last backup?
A network administrator wants to restrict inbound traffic to allow only HTTPS to the company website, denying all other inbound traffic from the internet. Which of the following would best accomplish this goal?
Which of the following will allow secure, remote access to internal applications?
A network administrator is unable to ping a remote server from a newly connected workstation that has been added to the network. Ping to 127.0.0.1 on the workstation is failing. Which of the following should the administrator perform to diagnose the problem?
A network administrator configures a new network discovery tool and is concerned that it might disrupt business operations. Which of the following scan types should the administrator configure?
A customer recently moved into a new office and notices that some wall plates are not working and are not properly labeled Which of the following tools would be best to identify the proper wiring in the IDF?
A firewall receives traffic on port 80 and forwards it to an internal server on port 88. Which of the following technologies is being leveraged?
A network technician needs to connect a new user to the company’s Wi-Fi network called SSID: business. When attempting to connect, two networks are listed as possible choices: SSID: business and SSID: myaccess. Which of the following attacks is occurring?
A company discovers on video surveillance recordings that an unauthorized person installed a rogue access point in its secure facility. Which of the following allowed the unauthorized person to do this?
Which of the following protocols uses the Dijkstra ' s Link State Algorithm to establish routes inside its routing table?
A network administrator configured a router interface as 10.0.0.95 255.255.255.240. The administrator discovers that the router is not routing packets to a web server with IP 10.0.0.81/28. Which of the following is the best explanation?
Early in the morning, an administrator installs a new DHCP server. In the afternoon, some users report they are experiencing network outages. Which of the following is the most likely issue?
Which of the following most likely determines the size of a rack for installation? (Select two).
A network technician sets up a computer on the accounting department floor for a user from the marketing department. The user reports that they cannot access the marketing department’s shared drives but can access the internet. Which of the following is the most likely cause of this issue?
Users on the network are experiencing slow throughput. A technician wants to increase throughput without changing any switch hardware. Which of the following solutions should the technician implement?
To reduce costs and increase mobility, a Chief Technology Officer (CTO) wants to adopt cloud services for the organization and its affiliates. To reduce the impact for users, the CTO wants key services to run from the on-site data center and enterprise services to run in the cloud. Which of the following deployment models is the best choice for the organization?
Which of the following is the best example of a networking appliance that connects different network segments and directs allowed traffic between specific segments?
A network engineer discovers network traffic that is sending confidential information to an unauthorized and unknown destination. Which of the following best describes the cause of this network traffic?
Which of the following troubleshooting steps provides a change advisory board with the information needed to make a decision?
After installing a series of Cat 8 keystones, a data center architect notices higher than normal interference during tests. Which of the following steps should the architect take to troubleshoot the issue?
Which of the following is used to stage copies of a website closer to geographically dispersed users?


A computer network diagram with many boxes and text AI-generated content may be incorrect.
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A screenshot of a computer AI-generated content may be incorrect.
A screenshot of a computer AI-generated content may be incorrect.
A screenshot of a computer AI-generated content may be incorrect.
A screenshot of a computer AI-generated content may be incorrect.
A screenshot of a computer AI-generated content may be incorrect.
A screenshot of a computer AI-generated content may be incorrect.
A screenshot of a computer AI-generated content may be incorrect.