CompTIAAssociate levelN10-009

N10-009 exam dumps: 329 free CompTIA Network+ practice questions

Free N10-009 practice questions for the Network+ exam, with the correct answer and a full explanation for every option. Read the first 10 below, browse all 329 by number, or take a timed practice exam.

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Free N10-009 practice questions

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N10-009 Question 1

Single answer1.1 Explain concepts related to the Open Systems Interconnection (OSI) reference model.

A network administrator is troubleshooting a problem in a small office after replacing an unmanaged switch with a managed switch. Users report that they can access printers and file shares within the local VLAN, but they cannot reach websites by name. When the administrator tests from a workstation, pinging the default gateway by IP address succeeds, and pinging a public IP address also succeeds. However, pinging a website FQDN fails. Based on the OSI model, at which layer is the problem most likely occurring?

A
Layer 3 - Network
B
Layer 4 - Transport
C
Layer 7 - Application
D
Layer 1 - Physical

Show answer and explanation

Correct answer: C

Explanation

This scenario is a classic example of using the OSI model to isolate a fault domain. Because the client can reach the default gateway and a public IP address, Layers 1 through 3 are demonstrably operational. The inability to reach a website by fully qualified domain name points to DNS resolution, which Network+ commonly associates with the Application layer (Layer 7) when mapping services to the OSI model. In practice, DNS uses UDP port 53 and sometimes TCP port 53, but exam objectives typically emphasize the service role rather than only the transport protocol. This layered troubleshooting approach aligns with standard networking best practices: verify physical connectivity first, then local IP configuration, then routed connectivity, and finally higher-layer services such as DNS.

A. Incorrect.
Incorrect. Layer 3 is responsible for logical addressing and routing, such as IP and default gateway communication. Because the workstation can successfully ping both its default gateway and a public IP address, Layer 3 connectivity is functioning. A candidate might choose this option because routing issues are common after switch changes, but the successful IP-based tests indicate the network layer is not the primary problem.
B. Incorrect.
Incorrect. Layer 4 handles end-to-end transport services such as TCP and UDP. While DNS commonly uses UDP and sometimes TCP, the scenario specifically points to successful connectivity by IP address but failure when using hostnames. That indicates name resolution rather than a general transport-layer failure. Someone might select this because DNS traffic uses transport-layer protocols, but the service issue itself is typically classified higher in the OSI model on Network+ exams.
C. Correct.
Correct. Layer 7 includes application services such as DNS, which translates hostnames to IP addresses. The workstation can communicate locally and externally by IP, so basic physical, data link, network, and likely transport connectivity are working. The failure only occurs when using an FQDN, which strongly indicates a DNS/name-resolution issue at the application layer.
D. Incorrect.
Incorrect. Layer 1 involves the physical medium, signaling, cabling, and link lights. If Layer 1 were the issue, the workstation would not be expected to reach the default gateway or a public IP address successfully. A user might pick this option because the problem started after a hardware replacement, but the evidence shows physical connectivity is intact.

N10-009 Question 2

Single answer1.1 Explain concepts related to the Open Systems Interconnection (OSI) reference model.

A network administrator is troubleshooting a problem in a warehouse. Several handheld devices can join the corporate Wi-Fi network and receive valid IP addresses from DHCP, but they cannot open the inventory application hosted on a remote server. The administrator successfully pings the default gateway from a handheld device, but a TCP connection test to the application server on port 443 fails. Based on the OSI model, which layer should the administrator investigate first?

A
Layer 2, because successful Wi-Fi association confirms the issue is with framing and MAC addressing
B
Layer 3, because DHCP and gateway reachability indicate IP addressing is the only remaining problem
C
Layer 4, because IP connectivity exists but the session to the application's TCP port cannot be established
D
Layer 7, because the inventory application is not opening, so the problem must be with the application itself

Show answer and explanation

Correct answer: C

Explanation

This scenario follows a practical OSI-based troubleshooting approach: start with the evidence and identify the highest confirmed working layer. The devices associate to Wi-Fi and obtain DHCP addresses, showing Layers 1 through 3 are at least partially operational. The administrator can also ping the default gateway, further supporting local IP connectivity. However, the failure to establish a TCP connection to port 443 points most directly to Layer 4, where TCP handles connection setup and port-based communication. In real environments, this commonly leads administrators to check host firewalls, network firewalls, ACLs, load balancers, or whether the server process is listening on the expected port. This aligns with standard troubleshooting practices described in CompTIA Network+ objectives and common vendor documentation from Cisco and Microsoft, which emphasize isolating faults by OSI layer and using protocol-specific tests such as ping for Layer 3 reachability and TCP port tests for Layer 4 validation.

A. Incorrect.
Incorrect. Layer 2 covers local link functions such as framing, MAC addressing, and wireless association. In this scenario, the devices are already joining Wi-Fi and obtaining network access, which suggests Layer 2 is functioning sufficiently for communication on the local segment. A candidate might choose this if they associate Wi-Fi problems with Layer 2 by default, but the evidence points higher in the stack.
B. Incorrect.
Incorrect. Layer 3 is responsible for logical addressing and routing. The handheld device receives a valid IP address via DHCP and can ping the default gateway, which indicates basic Layer 3 connectivity on the local network is working. While Layer 3 issues beyond the gateway could still exist in some cases, the failed TCP connection to port 443 more directly points to transport-level troubleshooting first.
C. Correct.
Correct. Layer 4, the Transport layer, is responsible for end-to-end communications using protocols such as TCP and UDP, including port numbers and connection establishment. Because the device has basic network connectivity but cannot establish a TCP connection to the server's HTTPS port, the administrator should first investigate Layer 4 issues such as blocked ports, ACLs, firewall rules, or a service not listening on the expected port.
D. Incorrect.
Incorrect. Layer 7 involves application services and interfaces, and an application fault is possible in some outages. However, the failed TCP connection test to port 443 indicates the problem occurs before normal application-layer communication can even begin. A candidate might select this because users report that the app will not open, but the test results narrow the issue to transport connectivity first.

N10-009 Question 3

Single answerLayer 1 - Physical

A technician is asked to extend network connectivity from a switch in one building to a small office in another building approximately 180 meters (590 feet) away. The path between the buildings runs alongside a parking lot with large electric motors and lighting equipment, and the area is prone to thunderstorms. The office needs a reliable 1 Gbps connection. Which of the following is the BEST Layer 1 solution?

A
Install Cat 6 UTP between the buildings because 1 Gbps Ethernet is supported on copper
B
Install single-mode or multimode fiber between the buildings with appropriate transceivers
C
Install Cat 5e STP between the buildings and bond the shielding at both ends
D
Install a copper Ethernet run with a PoE injector to overcome the distance limitation

Show answer and explanation

Correct answer: B

Explanation

For Network+ physical-layer scenarios, the best practice for interbuilding cabling is typically fiber optic cable rather than copper, especially when the distance exceeds 100 meters or when there is significant electromagnetic interference, lightning risk, or possible ground potential differences between buildings. TIA/EIA structured cabling guidance and Ethernet standards support the 100-meter maximum for twisted-pair Ethernet channels, while fiber is commonly recommended for campus and building-to-building backbone links. In this scenario, fiber meets the 1 Gbps requirement, avoids EMI from nearby electrical equipment, and provides electrical isolation that copper cannot.

A. Incorrect.
This is incorrect. Although 1000BASE-T can run at 1 Gbps over copper, standard twisted-pair Ethernet has a maximum horizontal channel length of 100 meters. A 180-meter run exceeds Ethernet copper specifications. In addition, copper between buildings is vulnerable to electromagnetic interference and electrical potential differences, especially in areas with lightning exposure.
B. Correct.
This is correct. Fiber optic cabling is the best physical-layer solution for an interbuilding link at 180 meters requiring 1 Gbps. Fiber easily supports this distance, is immune to electromagnetic interference from motors and lighting equipment, and does not conduct electricity, which helps protect against lightning-related surges and grounding issues between buildings. Either multimode or single-mode fiber could support 1 Gbps at this distance, depending on the chosen optics and design standards.
C. Incorrect.
This is incorrect. Shielded twisted pair can reduce the effects of electromagnetic interference, but it does not solve the 100-meter Ethernet distance limit for copper. It also remains a conductive medium, so it is still a poor choice for building-to-building runs where lightning and grounding differences are concerns. Some candidates choose this because STP sounds like the right answer for EMI, but the distance and surge risk make it unsuitable here.
D. Incorrect.
This is incorrect. PoE injectors provide power over Ethernet; they do not extend standard Ethernet data distance beyond the physical-layer limit for twisted-pair cabling. Copper would still exceed the supported length at 180 meters and would still be susceptible to interference and electrical hazards in this environment.

N10-009 Question 4

Single answerLayer 2 - Data link

A network administrator is troubleshooting intermittent connectivity between two departments connected through managed switches. Users in both departments can reach servers on their own VLANs, but devices in VLAN 20 on one switch cannot consistently communicate with devices in VLAN 20 on another switch. Devices in VLAN 10 work normally across the same uplink. The administrator confirms that routing is functioning and that the uplink between switches is physically up. Which of the following is the MOST likely cause?

A
The trunk link between the switches is not permitting VLAN 20
B
The default gateway for VLAN 20 is configured with the wrong subnet mask
C
A DNS server for VLAN 20 is unreachable
D
The switches are using different STP bridge priorities

Show answer and explanation

Correct answer: A

Explanation

This scenario focuses on a Layer 2 data link issue involving VLAN tagging and trunking between switches. When one VLAN works across a switch uplink and another does not, the best first suspicion is trunk misconfiguration, especially the allowed VLAN list or VLAN tagging mismatch. On IEEE 802.1Q trunks, each VLAN must be permitted across the trunk for its frames to traverse the link. Because VLAN 10 is functioning, the physical link and basic trunk operation are likely intact. Because routing is confirmed to be working, Layer 3 causes are less likely. Network+ candidates should recognize this as a practical troubleshooting pattern: isolate whether the problem is physical, Layer 2, or Layer 3, then compare working and non-working VLANs. Best practices from enterprise switch documentation commonly recommend verifying trunk status, native VLAN settings, and allowed VLAN lists when troubleshooting inter-switch VLAN communication.

A. Correct.
Correct. This is a classic Layer 2 trunking issue. If VLAN 10 traffic passes across the inter-switch uplink but VLAN 20 traffic does not, the most likely explanation is that VLAN 20 is missing from the allowed VLAN list on the trunk or the trunk is otherwise not carrying that VLAN. This would prevent frames tagged for VLAN 20 from traversing the uplink while allowing other VLANs, such as VLAN 10, to work normally.
B. Incorrect.
Incorrect. A wrong subnet mask on the default gateway is a Layer 3 configuration problem. The scenario specifically indicates that routing has already been verified and that the issue affects communication for the same VLAN across switches, which points more directly to a Layer 2 transport problem than to IP gateway configuration.
C. Incorrect.
Incorrect. DNS resolution problems affect name-to-IP lookups, not whether devices on the same VLAN can communicate at Layer 2 across a trunk. Even if DNS were unavailable, direct communication by IP would still be possible if the VLAN were correctly carried between switches.
D. Incorrect.
Incorrect. Spanning Tree Protocol bridge priority differences are normal in switched environments and are used to influence root bridge selection. Different priorities by themselves would not specifically prevent only VLAN 20 from traversing the uplink while VLAN 10 continues to function. If STP were blocking the only path, the impact would more likely be broader or tied to topology changes rather than one missing VLAN.

N10-009 Question 5

Single answerLayer 2 - Data link

A network administrator is replacing an unmanaged switch with a managed switch in a small office. After the cutover, users in the Finance department report they can no longer reach their accounting server, but users in other departments remain connected to their own resources. The accounting server is connected to switch port 12 and Finance users are connected to ports 1-8. The administrator verifies link lights are on and all devices have valid IP addresses. On the old switch, all ports were effectively in the same broadcast domain. On the new switch, ports 1-8 are assigned to VLAN 20, but port 12 is still in the default VLAN. Which action would MOST likely restore connectivity?

A
Assign port 12 to VLAN 20 so the server and Finance user ports are in the same Layer 2 broadcast domain
B
Configure port 12 with a static IP address in the same subnet as the Finance users
C
Enable STP PortFast on ports 1-8 and port 12 to reduce forwarding delays
D
Replace the patch cable connected to port 12 because VLAN mismatches commonly indicate a physical layer fault

Show answer and explanation

Correct answer: A

Explanation

This question tests practical Layer 2 switching knowledge, specifically VLAN behavior on managed switches. A VLAN creates a separate broadcast domain, so devices in different VLANs cannot communicate directly at Layer 2 without a Layer 3 device performing inter-VLAN routing. In this scenario, Finance clients were moved to VLAN 20, while the accounting server remained in the default VLAN, isolating it from those users. The proper fix is to assign the server's access port to VLAN 20 if the design intends for the server to be in the same Layer 2 segment as Finance. This aligns with standard Ethernet switching behavior and common vendor documentation for access port VLAN configuration on managed switches.

A. Correct.
Correct. VLANs are a Layer 2 segmentation mechanism that create separate broadcast domains on a switch. If Finance user ports are in VLAN 20 but the accounting server's port remains in the default VLAN, frames from the users will not reach the server at Layer 2 unless inter-VLAN routing is configured. Placing port 12 in VLAN 20 restores same-VLAN communication and is the most direct fix for this scenario.
B. Incorrect.
Incorrect. End devices such as servers receive IP addresses on their NICs, not on switch ports. Also, the scenario points to a Layer 2 VLAN membership issue, not an IP addressing problem. Even if the server has a valid IP address in the correct subnet, a VLAN mismatch can still prevent communication because the devices are isolated in different Layer 2 domains.
C. Incorrect.
Incorrect. PortFast helps access ports transition to forwarding state more quickly when connecting end devices, but it does not solve traffic isolation caused by different VLAN assignments. The symptoms described are persistent for one department and one server, which aligns with a VLAN configuration issue rather than STP convergence delay.
D. Incorrect.
Incorrect. A bad cable could cause loss of link or intermittent physical connectivity, but the administrator already confirmed link lights are on. A VLAN mismatch is a logical Layer 2 configuration issue, not a cabling fault. Replacing the cable would be a plausible troubleshooting step in some cases, but it is not the most likely solution here.

N10-009 Question 6

Single answerLayer 3 - Network

A company has two IPv4 subnets connected by a router: 192.168.10.0/24 for the accounting department and 192.168.20.0/24 for the warehouse. Users in accounting can reach hosts in their own subnet and can ping the router interface at 192.168.10.1, but they cannot reach any devices in the warehouse subnet. A technician verifies that the router interface for the warehouse network is up and configured as 192.168.20.1/24. On an accounting PC, the IP configuration is 192.168.10.50/24 with a default gateway of 192.168.10.254. Which action is the BEST way to restore connectivity between the two subnets?

A
Change the accounting PC default gateway to 192.168.10.1
B
Change the accounting PC subnet mask to 255.255.0.0
C
Assign the warehouse router interface an address in the 192.168.10.0/24 subnet
D
Enable NAT on the router for traffic between the two internal subnets

Show answer and explanation

Correct answer: A

Explanation

This scenario tests practical Layer 3 troubleshooting. A host uses its subnet mask to determine whether a destination is local or remote. If the destination is remote, the host forwards the packet to its configured default gateway, which must be a router interface on the same local subnet. Here, the accounting PC is on 192.168.10.0/24, and the known router interface on that subnet is 192.168.10.1. Because the PC is configured with 192.168.10.254 instead, traffic for 192.168.20.0/24 is sent to the wrong gateway and cannot be routed correctly. Best practice for IPv4 inter-subnet communication is to configure each host with the correct local IP, subnet mask, and default gateway that points to the local router interface. This aligns with standard TCP/IP host routing behavior described in common networking references and vendor documentation such as Cisco and Microsoft TCP/IP configuration guidance.

A. Correct.
Correct. For hosts to reach remote Layer 3 networks, their default gateway must be the IP address of the local router interface on the same subnet. The accounting PC is in 192.168.10.0/24, and the reachable router interface on that subnet is 192.168.10.1. Using 192.168.10.254 as the gateway would prevent proper forwarding unless a router interface actually existed at that address. Since the user can already ping 192.168.10.1, updating the default gateway to that address is the appropriate fix.
B. Incorrect.
Incorrect. Changing the mask to 255.255.0.0 would make the host believe that 192.168.20.0 is part of the local network range, causing it to attempt direct Layer 2 delivery instead of sending traffic to a router. Because the warehouse hosts are actually on a different subnet and likely a different broadcast domain, this would not solve the routing problem and would create addressing issues.
C. Incorrect.
Incorrect. Router interfaces that connect different networks must be in the correct subnet for each connected segment. The warehouse-side interface should remain in 192.168.20.0/24 so it can serve as the gateway for that subnet. Moving it into 192.168.10.0/24 would break the Layer 3 boundary and create an invalid design with overlapping interface addressing for separate segments.
D. Incorrect.
Incorrect. NAT is not required for routing between two internal private subnets directly connected to the same router. NAT is typically used when translating between private and public addresses or between overlapping address spaces. The issue here is basic host gateway configuration, not address translation.

N10-009 Question 7

Single answerLayer 3 - Network

A network administrator is troubleshooting connectivity between two IPv4 subnets in a small branch office. Hosts on VLAN 10 (192.168.10.0/24) can reach their default gateway at 192.168.10.1, and hosts on VLAN 20 (192.168.20.0/24) can reach their default gateway at 192.168.20.1. However, users on VLAN 10 cannot access a file server at 192.168.20.50, and users on VLAN 20 cannot reach any devices on VLAN 10. The Layer 3 switch has SVIs configured for both VLANs, and the administrator confirms both interfaces are up/up. Which of the following is the MOST likely cause of the problem?

A
IP routing is disabled on the Layer 3 switch
B
The file server is using the wrong DNS server address
C
A duplex mismatch exists between the switch and the file server
D
The hosts in VLAN 10 need a default gateway in a different subnet

Show answer and explanation

Correct answer: A

Explanation

This question tests practical Layer 3 troubleshooting in an inter-VLAN routing scenario. When each VLAN can reach its own SVI but cannot communicate with other VLANs, one of the first checks is whether Layer 3 routing is actually enabled on the multilayer switch. Best practice when troubleshooting is to verify: 1) host IP configuration and subnet mask, 2) default gateway reachability, 3) SVI status, and 4) routing functionality between directly connected networks. Vendor documentation for multilayer switches commonly notes that creating VLAN interfaces alone does not automatically enable IPv4 routing between them; the device must be operating with Layer 3 forwarding enabled. This aligns with standard Network+ expectations for diagnosing Layer 3 connectivity issues.

A. Correct.
Correct. On a multilayer switch, having SVIs configured and operational is not enough by itself to route traffic between VLANs. Inter-VLAN communication requires Layer 3 forwarding to be enabled, typically with an 'ip routing' command or equivalent platform feature. If hosts can reach their own default gateway but cannot reach devices in the other subnet, disabled IP routing is a very plausible root cause.
B. Incorrect.
Incorrect. DNS configuration affects name resolution, not basic Layer 3 reachability by IP address. In this scenario, users cannot reach devices across subnets even when the destination is identified by its IPv4 address (192.168.20.50), so DNS is not the likely cause.
C. Incorrect.
Incorrect. A duplex mismatch can cause poor performance, late collisions, frame errors, and intermittent connectivity on a specific link, but it would not typically prevent all hosts in one VLAN from reaching all devices in another subnet through otherwise healthy SVIs. The issue described is broader and points to a routing problem rather than a single access-port performance issue.
D. Incorrect.
Incorrect. Hosts in VLAN 10 should use a default gateway within their own subnet, such as 192.168.10.1. A default gateway in a different subnet would be invalid for normal host configuration unless special mechanisms are in place. Since the hosts can already reach 192.168.10.1, their gateway placement appears correct.

N10-009 Question 8

Single answerLayer 4 - Transport

A company has deployed a voice-over-IP (VoIP) softphone application to remote users. After a firewall policy change, users can still log in to the VoIP service, but during calls they experience choppy audio and frequent dropouts. Packet captures show the signaling session establishes successfully, but the voice stream suffers when the network is congested. Which transport-layer change would MOST likely improve call quality while keeping the application behavior appropriate for real-time voice traffic?

A
Configure the voice media stream to use UDP instead of TCP
B
Force the softphone signaling and media traffic to use only TCP port 443
C
Enable larger TCP receive windows for the voice media stream
D
Require the voice application to retransmit lost audio packets until acknowledged

Show answer and explanation

Correct answer: A

Explanation

This question tests practical understanding of Layer 4 transport behavior. For real-time applications such as VoIP, the transport protocol choice directly affects latency, jitter, and packet recovery behavior. UDP is commonly used for voice media because it is connectionless and does not provide retransmission, sequencing enforcement, or acknowledgments like TCP. That makes it better suited for time-sensitive traffic where delayed packets degrade user experience. TCP is more appropriate for applications that require reliable, ordered delivery, such as file transfers or web content. In common VoIP designs, signaling may use TCP or UDP depending on the protocol and implementation, but the media path is typically carried over UDP. This aligns with IETF real-time media practices, including RTP running over UDP, and with Network+ best-practice distinctions between reliable transport and low-latency transport.

A. Correct.
Correct. Real-time voice media is typically carried over UDP because UDP has lower overhead and does not wait for acknowledgments or retransmissions. For voice traffic, late packets are often as useless as lost packets, so avoiding TCP-style recovery behavior helps reduce latency and jitter. This is the transport-layer choice most aligned with maintaining call quality during congestion.
B. Incorrect.
Incorrect. Although tunneling traffic over TCP 443 may help with firewall traversal, using TCP for real-time voice media can worsen performance because retransmissions, in-order delivery requirements, and congestion recovery can increase delay and jitter. The scenario already indicates signaling works; the issue is media quality under congestion.
C. Incorrect.
Incorrect. TCP receive window tuning is relevant to TCP flow control, but it does not solve the core issue for real-time audio. Larger windows can improve throughput for bulk transfers, not interactive media that is sensitive to delay variation. Voice streams generally prioritize timely delivery over reliable retransmission.
D. Incorrect.
Incorrect. Requiring retransmission and acknowledgment of lost audio packets introduces additional delay, which is harmful to conversational voice. This reflects a common misconception that reliability is always preferable. At the transport layer, real-time applications usually accept some packet loss rather than incur the latency caused by recovery mechanisms.

N10-009 Question 9

Single answerLayer 4 - Transport

A company is rolling out a cloud-based voice and video collaboration platform to several branch offices. Users report that during busy periods, calls connect successfully but audio becomes choppy and video freezes for a few seconds at a time. Network monitoring shows occasional packet loss and variable latency on the WAN links. The application team confirms the platform uses both TCP and UDP at the transport layer. Which protocol should the real-time media streams use to provide the best user experience under these conditions?

A
TCP, because retransmissions ensure missing voice and video packets are delivered in order
B
UDP, because low-latency delivery is typically preferred over retransmission delays for real-time traffic
C
TCP, because connection-oriented sessions automatically eliminate jitter on congested links
D
UDP, because it guarantees packet delivery while using less bandwidth than TCP

Show answer and explanation

Correct answer: B

Explanation

The best answer is UDP because real-time applications such as voice and video typically prioritize low latency over guaranteed delivery. At Layer 4, TCP and UDP serve different purposes: TCP provides reliable, ordered delivery with acknowledgments and retransmissions, while UDP provides connectionless, low-overhead transport without delivery guarantees. For interactive media, delayed packets are often useless by the time they arrive, so retransmission behavior can reduce quality rather than improve it. This is why technologies such as VoIP and many video conferencing platforms commonly use UDP for media streams, even if TCP may still be used elsewhere in the application stack for signaling, authentication, or session management. This approach is consistent with standard networking best practices and with the transport-layer behavior described in common references such as RFC 768 for UDP and RFC 9293 for TCP.

A. Incorrect.
Incorrect. TCP provides reliability through sequencing, acknowledgments, flow control, and retransmissions, which is valuable for applications such as file transfers and web traffic. However, for real-time voice and video, waiting for lost packets to be retransmitted often introduces additional delay that degrades call quality more than simply losing a small amount of media traffic. This is a common misconception when people equate reliable delivery with better application performance in all cases.
B. Correct.
Correct. UDP is commonly used for real-time media streams because it has lower overhead and does not wait for acknowledgments or retransmissions. In voice and video communications, timely delivery is usually more important than perfect delivery. Small amounts of packet loss are often preferable to the extra latency introduced by TCP recovery mechanisms. This aligns with common design practices for VoIP and video conferencing, where transport-layer efficiency supports acceptable quality under variable network conditions.
C. Incorrect.
Incorrect. TCP is connection-oriented, but that does not mean it eliminates jitter. Jitter is variation in packet arrival times caused by network conditions such as congestion, queuing, and path changes. TCP may even worsen perceived performance for real-time applications because retransmissions and congestion control can add delay. Someone might choose this option by confusing session establishment and reliability with quality-of-service improvements.
D. Incorrect.
Incorrect. UDP does not guarantee packet delivery, packet order, or error recovery. It is a connectionless transport protocol with minimal overhead. While UDP often uses less overhead than TCP, the statement is wrong because it incorrectly claims guaranteed delivery. This distractor targets the common misunderstanding that a lighter protocol can still provide the same reliability guarantees as TCP.

N10-009 Question 10

Single answerLayer 5 - Session

A company uses a terminal server environment where remote employees connect to an internal Windows application through Microsoft Remote Desktop Services. Users report that after brief WAN interruptions, their screens freeze and they must sign in again, losing unsaved work. Network monitoring shows that IP connectivity is usually restored within seconds, but the user session is not being resumed. Which action would best address this issue from an OSI Layer 5 perspective?

A
Configure session persistence and reconnection settings on the Remote Desktop Services host
B
Replace the access switches with models that support a larger MAC address table
C
Disable TCP window scaling on client devices
D
Change the cabling between the core switch and firewall from Cat 6 to fiber

Show answer and explanation

Correct answer: A

Explanation

This question focuses on the OSI Session layer's role in maintaining dialog state between applications. In real environments, technologies such as Microsoft Remote Desktop Services rely on session management features to let users reconnect to an existing session after transient network loss. When users must sign in again and lose unsaved work even though connectivity returns quickly, the most appropriate fix is to review session timeout, disconnection, and reconnection settings rather than changing switching hardware, cabling, or TCP tuning. This aligns with common vendor guidance for remote application delivery platforms, where preserving user context across short interruptions is handled through session management and reconnection policies rather than lower-layer network changes.

A. Correct.
Correct. OSI Layer 5, the Session layer, is responsible for establishing, managing, and terminating communication sessions between applications. In a Remote Desktop Services environment, configuring disconnected session limits, session persistence, and reconnection behavior directly addresses the problem of users needing to reauthenticate and losing application state after a brief interruption. This is the option that most closely maps to session management rather than lower-layer connectivity changes.
B. Incorrect.
Incorrect. A larger MAC address table is a Layer 2 switching consideration and would be relevant for issues such as MAC flooding or address learning limits. It does not address the application session being dropped after a temporary WAN interruption.
C. Incorrect.
Incorrect. TCP window scaling is a transport-layer performance feature related to throughput and receive window size. While transport issues can affect responsiveness, disabling window scaling would not be the best solution for preserving and resuming authenticated user sessions after a short disconnect.
D. Incorrect.
Incorrect. Changing copper cabling to fiber between infrastructure devices affects the Physical layer and possibly bandwidth or distance limitations. The scenario already states that IP connectivity returns quickly, so the primary issue is session continuity, not the medium used for the uplink.

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What the N10-009 exam covers

Official Network+ exam domains and weightings.

Networking Fundamentals
24% of exam
Network Implementations
19% of exam
Network Operations
16% of exam
Network Security
19% of exam
Network Troubleshooting
22% of exam

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N10-009 exam dumps FAQ

Are these N10-009 dumps real exam questions?

No. These are original practice questions written to the Network+ exam objectives, not questions copied from a live exam. Memorising leaked questions violates CompTIA's candidate agreement and stops working the moment the question pool rotates. Use this bank to check your understanding of each domain and to find the topics you still need to study.

How many N10-009 practice questions are there?

329 questions, each with the correct answer, an explanation of the answer, and a note on why every other option is wrong. The first 10 are on this page and every question has its own page linked below.

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What topics does the N10-009 exam cover?

The official exam domains are: Networking Fundamentals; Network Implementations; Network Operations; Network Security; Network Troubleshooting.

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