CompTIA  N10-009  Network+  Exam Dumps and Practice Test Questions Set 3 Q41-60

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Question 41

 A network administrator wants to prevent unauthorized devices from connecting to switch ports and potentially accessing sensitive information. Which feature should be implemented?

A) Port security
B) VLAN trunking
C) QoS
D) LACP

Answer: A) Port security

Explanation:

A) This feature allows a switch to restrict access to specific devices based on their hardware addresses. By configuring allowed addresses per port, administrators can ensure that only known devices can communicate through the interface. If an unknown device attempts to connect, the switch can shut down the port, send an alert, or drop traffic, depending on the configuration. This helps prevent unauthorized access, protects network resources, and mitigates risks from rogue devices or compromised endpoints. It is particularly effective in environments where physical access to network ports is possible but must be controlled. By limiting connectivity to trusted devices, the feature enforces security at the data-link layer.

B) Allowing multiple logical groups to traverse a single trunk link facilitates communication for multiple VLANs but does not restrict which devices can connect to a port. While trunking organizes traffic, it does not prevent unauthorized hardware from accessing a network.

C) Prioritizing specific types of traffic improves performance for critical applications but has no effect on controlling which devices can attach to a port. QoS manages bandwidth and latency rather than access permissions.

D) Combining multiple interfaces to increase bandwidth or provide redundancy improves throughput but does not enforce access restrictions. LACP deals with load balancing and fault tolerance, not device authentication.

The correct solution is the feature that enforces access restrictions on a per-port basis, which is the first choice.

Question 42

A technician is troubleshooting a VoIP deployment and notices that voice calls have delays, jitter, and occasional packet loss. Which network feature should be used to improve call quality?

A) QoS
B) STP
C) VLAN pruning
D) DHCP relay

Answer: A) QoS

Explanation:

A) This method prioritizes latency-sensitive traffic, such as voice or video, over less time-critical data. By tagging, queuing, and scheduling packets appropriately, it ensures that high-priority traffic experiences minimal delay, reduced jitter, and fewer dropped packets. This is essential in VoIP deployments because voice quality deteriorates rapidly with inconsistent packet delivery. QoS policies can assign higher priority to voice VLANs or specific protocols, guaranteeing bandwidth and predictable performance. It also allows administrators to manage contention on congested links, ensuring that voice traffic is not delayed by bulk data transfers or other non-critical communications.

B) Maintaining a loop-free topology ensures network stability and prevents broadcast storms but does not address latency, jitter, or packet loss for real-time applications. While essential for overall network health, it does not solve quality-of-service issues specific to voice traffic.

C) Limiting unnecessary VLAN traffic on trunk links reduces overhead but does not directly improve packet timing or delivery reliability. It helps efficiency but does not guarantee prioritized handling of voice traffic, which is critical for call quality.

D) Forwarding address assignment requests across subnets ensures clients receive correct network configuration but does not influence ongoing traffic performance. It has no impact on latency, jitter, or packet loss for real-time sessions.

Prioritizing network traffic specifically to support voice and video requires QoS, making the first choice correct.

Question 43

 A network technician notices that a switch repeatedly logs BPDU guard errors and shuts down ports unexpectedly. What is the cause of this problem?

A) Unauthorized device connecting to edge ports
B) Misconfigured DHCP server
C) Incorrect subnet mask on hosts
D) Duplicate NAT entries

Answer: A) Unauthorized device connecting to edge ports

Explanation:

A) When BPDU guard is enabled on edge ports, it expects no Bridge Protocol Data Units from devices connected to those ports. If a switch receives a BPDU from an unauthorized device, it interprets this as a potential loop and immediately disables the port to protect the network. This prevents misconfigurations or rogue switches from introducing loops into the topology. The behavior ensures stability and enforces edge-port policies, as edge ports are intended for end-user devices rather than other switches. Repeated errors usually indicate either misconnected equipment or attempts to attach devices that act like switches, triggering the protection mechanism.

B) DHCP configuration issues affect IP address assignment but do not trigger BPDU guard or port shutdowns. They may cause connectivity problems but not the specific event of BPDU reception and port disabling.

C) Incorrect subnet masks prevent proper host communication but have no effect on layer-two BPDU traffic. They cannot cause the switch to log BPDU errors or shut down ports.

D) Duplicate address translations on NAT devices influence IP-layer routing and connectivity, but BPDU guard operates at the data-link layer. NAT conflicts do not generate BPDU guard events.

The shutdown behavior occurs because BPDU guard detects unexpected bridging signals on edge ports, making the first explanation correct.

Question 44

A network engineer is planning a wireless deployment in a multi-story building. The goal is to maximize coverage while minimizing interference and channel overlap. Which planning strategy should be implemented?

A) Site survey and channel planning
B) Increasing MTU size
C) Enabling port security
D) DHCP reservation

Answer: A) Site survey and channel planning

Explanation:

A) Conducting a detailed analysis of the physical environment allows the engineer to understand signal propagation, reflection, and attenuation caused by walls, furniture, and building materials. By mapping coverage areas, selecting appropriate access point placement, and assigning channels to minimize overlap, interference is reduced, and consistent performance is achieved. Proper channel planning is critical in dense environments where multiple access points operate in proximity. This approach ensures that adjacent access points do not operate on the same or overlapping channels, which would create co-channel interference and degrade performance. By using measurement tools and predictive modeling, the engineer can optimize both coverage and capacity.

B) Changing the maximum transmission unit size affects frame payloads but does not impact radio frequency interference or coverage patterns. It may influence packet fragmentation but does not address wireless planning concerns.

C) Restricting access to authorized devices enhances security but does not optimize coverage, channel selection, or performance. Security measures alone cannot solve interference issues.

D) Reserving IP addresses ensures predictable address allocation but has no effect on physical wireless coverage or signal overlap. It is unrelated to RF planning.

Only a methodical survey and careful channel assignment directly optimize coverage while minimizing interference.

Question 45

A company wants to ensure that all internet-bound traffic from branch offices passes through a central security device for inspection. Which network design concept achieves this?

A) Backhaul to central site
B) Split tunneling
C) Direct internet access at branch
D) VLAN segmentation

Answer: A) Backhaul to central site

Explanation:

A) Routing traffic from remote locations to a central point ensures that all communications can be inspected by firewalls, intrusion detection systems, or content filtering appliances. This centralized inspection model provides consistent policy enforcement, simplifies monitoring, and ensures that threats are identified before they reach the internal network. Branch offices connect to the central site using secure tunnels or private links, sending all outbound traffic through the security devices before reaching the internet. This model prevents bypassing of security controls that could occur if branches connected directly to the public network.

B) Allowing traffic to bypass central inspection increases efficiency for latency-sensitive applications but does not guarantee that all traffic is monitored. It creates potential gaps in security enforcement, making it unsuitable when full inspection is required.

C) Direct internet access from branch locations improves performance for cloud applications but bypasses central security devices. This leaves branches vulnerable and does not meet the requirement for inspection of all traffic.

D) Separating devices into logical groups controls internal traffic flow and isolates broadcast domains but does not direct internet-bound traffic through a specific inspection point. VLANs segment the network rather than enforce centralized inspection.

Sending traffic to a central site before reaching the internet ensures comprehensive inspection and policy enforcement, making the first choice correct.

Question 46

A network engineer wants to verify the end-to-end connectivity and response time between a workstation and a remote server. Which command should be used?

A) Ping
B) Traceroute
C) Netstat
D) ARP

Answer: A) Ping

Explanation:

A) This command sends echo request messages to a target host and measures the time it takes to receive echo replies. By analyzing the round-trip time, the administrator can determine both connectivity and latency between the source and destination. It also indicates packet loss if some requests go unanswered. This makes it a simple yet effective tool for quickly verifying whether a host is reachable and whether the connection is performing within acceptable time parameters. It operates at the ICMP layer, which is widely supported by devices and commonly allowed through firewalls, making it suitable for basic end-to-end network testing.

B) This utility reveals each hop along the path to a destination and provides timing information per hop. While useful for diagnosing routing issues, it does not give a simple measure of overall connectivity and round-trip time in a concise form. Its primary focus is path analysis, not straightforward reachability or latency measurement.

C) This command shows current connections and listening ports on a host. It helps identify which applications are using network resources, but it does not measure end-to-end connectivity or response times to a remote host. It is a local diagnostic tool for session monitoring.

D) This mechanism resolves IP addresses to physical hardware addresses on a local segment. It does not test connectivity or measure round-trip times and cannot provide information about the reachability of remote systems. It is purely a link-layer resolution process.

The correct tool is designed specifically for confirming whether a host is reachable and measuring the response time, making the first choice correct.

Question 47

 A network technician is installing a new wireless access point and wants to minimize interference from neighboring access points in the same building. Which action should be taken?

A) Configure non-overlapping channels
B) Enable DHCP on the AP
C) Increase MTU size
D) Disable SSID broadcast

Answer: A) Configure non-overlapping channels

Explanation:

A) Assigning channels that do not overlap with neighboring access points reduces co-channel interference. In the 2.4 GHz band, there are limited non-overlapping channels, and selecting them carefully ensures that adjacent access points do not interfere with each other. This results in higher throughput, fewer retransmissions, and improved overall performance for clients. Proper channel planning is critical in dense environments to prevent collisions at the radio layer and maintain predictable connectivity.

B) Enabling address assignment services affects how devices obtain IP configurations but has no effect on radio frequency interference. It is unrelated to minimizing co-channel or adjacent-channel interference.

C) Changing the maximum transmission unit size influences how packets are segmented and transmitted at the network layer but does not address radio frequency overlap or signal interference. It has no effect on wireless channel performance.

D) Hiding the network identifier only affects whether clients can see the access point’s SSID. It does not influence channel usage or interference, nor does it improve throughput or connectivity in environments with overlapping APs.

Choosing non-overlapping channels directly addresses the interference problem, making it the correct solution.

Question 48

A technician needs to securely connect two branch offices over the public internet and ensure all traffic is encrypted. Which solution should be implemented?

A) Site-to-site VPN
B) NAT
C) VLAN trunking
D) Proxy server

Answer: A) Site-to-site VPN

Explanation:

A) This solution establishes an encrypted tunnel between two locations, ensuring that all communication between the branches is confidential and tamper-proof. Traffic is encapsulated, preventing eavesdropping, modification, or replay attacks while traversing the untrusted internet. It allows each branch to communicate as if connected via a private network without the need for dedicated physical links. Policies can be applied to route specific traffic through the secure tunnel, ensuring sensitive data remains protected. Site-to-site VPNs are widely used for interconnecting offices and provide transparent connectivity for applications without requiring changes to endpoint configurations.

B) Translating addresses allows multiple devices to share a single public IP and provides some privacy for internal addresses but does not encrypt traffic. NAT alone does not secure data in transit or provide confidentiality.

C) Allowing multiple logical groups to traverse a single link helps organize traffic within a network but does not provide encryption or secure communication over public infrastructure. VLANs are logical segmentation tools, not security solutions for remote traffic.

D) Acting as an intermediary for client requests, this device can filter or cache traffic but does not establish encrypted tunnels between sites. It does not protect all traffic between offices over untrusted networks.

The only solution that ensures complete confidentiality for all inter-office traffic over the internet is the encrypted tunnel provided by a site-to-site VPN.

Question 49

A network engineer wants to monitor bandwidth utilization on multiple switches and generate reports for capacity planning. Which tool or protocol is most suitable?

A) SNMP
B) Ping
C) ARP
D) iPerf

Answer: A) SNMP

Explanation:

A) This management protocol allows network devices to report various statistics to centralized monitoring systems. It can provide data on interface utilization, errors, discards, CPU load, memory usage, and more. By polling switches and other devices periodically, administrators can build historical records, generate graphs, and analyze trends for capacity planning. SNMP supports alerts for thresholds, allowing proactive management before performance degrades. It is widely supported by enterprise devices and provides a standardized approach to network monitoring.

B) Sending echo requests confirms reachability and measures round-trip times but does not provide historical utilization or performance metrics. Ping is useful for simple connectivity tests but not for ongoing monitoring or reporting.

C) Resolving IP addresses to hardware addresses allows a device to forward traffic on a local segment but does not provide statistics or bandwidth utilization information. It is a link-layer mechanism, not a monitoring protocol.

D) Measuring end-to-end performance between two endpoints provides throughput and latency data temporarily but cannot poll multiple switches or generate historical reports for capacity planning. It is primarily a diagnostic tool rather than a monitoring framework.

The protocol in the first choice is specifically designed for collecting device statistics, making it the correct option.

Question 50

A technician is troubleshooting a network and observes that clients on one switch cannot communicate with clients on a different switch, even though both switches are physically connected. Which configuration issue is most likely?

A) VLAN mismatch
B) Incorrect MTU size
C) Duplicate IP addresses
D) Wrong SSID

Answer: A) VLAN mismatch

Explanation:

A) When switches are configured with inconsistent VLAN assignments or trunking settings, devices in the same VLAN on one switch cannot reach their counterparts on another switch. Even though the physical link exists, logical segmentation prevents proper forwarding across the network. VLAN mismatches can occur when a trunk port is configured incorrectly, or when the native VLAN is different on each end. This results in devices being effectively isolated despite physical connectivity. It is a common cause of communication failure between switches and often requires verification of VLAN IDs, trunking modes, and native VLAN configuration.

B) Adjusting frame payload sizes affects packet handling but does not prevent connectivity caused by logical VLAN segmentation. MTU mismatches can cause fragmentation or drops but not complete isolation between VLANs.

C) Address duplication can result in intermittent connectivity or conflicts but would not prevent all devices on one switch from communicating with another if the VLAN configuration is correct. Duplicate addresses create localized issues rather than full VLAN isolation.

D) Wireless network identifiers affect wireless clients and access point association, not wired VLAN communication. SSID misconfiguration is irrelevant to inter-switch connectivity over physical links.

A VLAN mismatch prevents proper layer-two forwarding across switches, making it the correct explanation for the issue.

Question 51

A network administrator needs to remotely manage multiple switches using a secure protocol that encrypts both authentication and management traffic. Which protocol should be used?

A) SSH
B) Telnet
C) HTTP
D) SNMPv1

Answer: A) SSH

Explanation:

A) This protocol provides encrypted communication for remote management, ensuring that login credentials and configuration commands are not sent in clear text. It establishes a secure session between the administrator and the network device, protecting against eavesdropping or man-in-the-middle attacks. SSH also supports strong authentication methods and can be used to securely tunnel other management protocols. This makes it ideal for accessing switches, routers, and other network equipment remotely without exposing sensitive information over the network.

B) This legacy protocol allows remote command-line access but transmits data, including credentials, in plain text. It is vulnerable to interception and is not suitable for secure network management in modern environments.

C) Using the web-based interface over unencrypted HTTP exposes credentials and configuration commands to potential interception. While convenient for management, it does not provide confidentiality or integrity protection.

D) The original version of this network management protocol sends polling and configuration information in clear text. It lacks encryption and is susceptible to interception, making it unsuitable for secure remote management.

SSH is the only protocol among these that ensures secure, encrypted remote access for managing network devices, making it the correct choice.

Question 52

A technician is deploying a new server that requires minimal latency and jitter for streaming applications. Which type of network should be used to prioritize this traffic?

A) Layer 2 network with QoS enabled
B) Standard VLAN without QoS
C) Network using only NAT
D) Wireless network on 2.4 GHz only

Answer: A) Layer 2 network with QoS enabled

Explanation:

A) Configuring a layer-two environment with quality-of-service policies allows certain traffic, like voice or streaming media, to be prioritized over less critical traffic. This ensures minimal delay, low jitter, and predictable packet delivery, which is essential for real-time applications. Prioritization mechanisms, such as traffic classification and scheduling, enable the network to handle congestion without impacting performance-sensitive applications. Using QoS at the switch level guarantees that the server’s traffic receives appropriate treatment across the network path, maintaining the required performance metrics.

B) A basic logical segmentation does not provide prioritization, so latency-sensitive traffic could be delayed during congestion. VLANs alone separate traffic but do not guarantee quality or timing performance.

C) Translating addresses for network devices provides address conservation and basic connectivity but does not influence traffic prioritization or latency. NAT cannot ensure low delay or reduce jitter for streaming applications.

D) Using the 2.4 GHz band may introduce interference, limited channels, and unpredictable latency. Wireless networks on this band are more prone to congestion, making them unsuitable for applications requiring strict performance guarantees.

The correct choice is the configuration that combines layer-two switching with traffic prioritization to maintain low latency and jitter.

Question 53

A network engineer wants to prevent users from connecting unauthorized devices to a network switch while still allowing flexibility for legitimate endpoint changes. Which approach is best?

A) Enable port security with sticky MAC addresses
B) Disable all unused ports permanently
C) Use only static IP addressing
D) Implement split tunneling on VPN clients

Answer: A) Enable port security with sticky MAC addresses

Explanation:

A) Sticky MAC addresses allow the switch to dynamically learn connected device addresses and store them as authorized entries for the port. This enables legitimate devices to connect without manual configuration while preventing unauthorized devices from gaining access. If a different MAC address is detected, the switch can block traffic or shut down the port. This approach combines flexibility and security, reducing administrative effort while maintaining control over endpoint access. Sticky addresses automatically adapt to minor legitimate changes while enforcing security policies at the data-link layer.

B) Permanently disabling ports reduces security risk but limits flexibility for legitimate endpoint moves or changes. It can disrupt operations when devices need to be connected temporarily or relocated.

C) Restricting devices using static IP addresses ensures predictable assignment but does not prevent unauthorized devices from physically connecting to a port. IP addresses can be spoofed, making this approach insufficient for access control.

D) Allowing some traffic to bypass the secure tunnel on VPN clients controls routing and traffic flow but does not prevent unauthorized devices from attaching to a switch port. It addresses remote access policy rather than local endpoint security.

Sticky MAC enforcement provides a balance of security and operational flexibility, making it the correct choice.

Question 54

A technician is designing a network that requires redundant paths but wants to avoid loops that could disrupt communication. Which protocol should be implemented?

A) Spanning Tree Protocol (STP)
B) DHCP
C) RIP
D) ICMP

Answer: A) Spanning Tree Protocol (STP)

Explanation:

A) This protocol prevents layer-two loops by dynamically identifying redundant paths and selectively blocking some interfaces while allowing backup paths to remain available. If a primary link fails, STP recalculates the topology and activates blocked paths to maintain connectivity without creating broadcast storms. This ensures redundancy without compromising network stability. It is widely used in switched networks to prevent loops while taking advantage of multiple available paths, balancing reliability and loop prevention automatically.

B) Assigning addresses dynamically ensures proper host configuration but does not control path selection or prevent loops. DHCP is unrelated to redundancy management or loop prevention.

C) This distance-vector routing protocol manages path selection at layer three for IP networks but does not prevent layer-two loops. Routing protocols operate above the switching layer and cannot address bridging loops in the LAN.

D) Sending echo messages tests reachability and latency but does not control path selection or prevent loops. ICMP is a diagnostic protocol and does not manage network topology.

The protocol designed specifically to manage redundant paths and prevent switching loops is the first choice.

Question 55

 A network engineer wants to isolate a group of servers to improve security while still allowing controlled access to the rest of the network. Which solution should be implemented?

A) Private VLAN
B) Increase MTU size
C) Enable Telnet
D) Change DNS servers

Answer: A) Private VLAN

Explanation:

A) Private VLANs allow servers to be segmented into isolated subgroups while still connecting through a shared primary VLAN. Hosts in a private VLAN cannot communicate directly with each other but can communicate with a designated router or gateway. This provides internal isolation for security, limiting lateral movement by potential attackers, while still permitting controlled access to resources outside the isolated group. It is commonly used in data centers to separate servers or sensitive hosts without creating completely separate VLANs for each device, providing both security and efficient resource use.

B) Adjusting packet size affects fragmentation but does not provide isolation or security segmentation. It does not prevent unauthorized communication between servers.

C) Enabling a legacy remote management protocol allows access but does not isolate traffic. In fact, Telnet transmits credentials in clear text and can introduce security vulnerabilities rather than improving isolation.

D) Changing naming servers affects address resolution but does not isolate network traffic or enforce access control between servers. DNS modifications do not provide segmentation for security purposes.

Private VLANs provide the required isolation while allowing controlled external access, making it the correct choice.

Question 56

A network technician needs to verify the path packets take from a workstation to a remote web server and identify where delays occur. Which tool should be used?

A) Traceroute
B) Ping
C) Netstat
D) ARP

Answer: A) Traceroute

Explanation:

A) This diagnostic tool identifies each network hop between the source and destination. It sends packets with incrementally increasing time-to-live values and records the responding devices along the path. This allows administrators to see where latency is introduced, identify routing problems, and pinpoint segments causing delays. Traceroute is essential for troubleshooting path-related issues because it provides detailed insight into the route packets take through the network and the response time at each intermediate device, helping isolate bottlenecks.

B) Sending echo requests provides basic connectivity verification and round-trip time but does not reveal the individual hops between the source and destination. Ping cannot indicate where in the path delays are occurring.

C) Displaying active connections and listening ports is useful for monitoring local host activity but does not provide path information or latency per hop to a remote server. It is a local diagnostic tool rather than a path analysis tool.

D) Resolving hardware addresses to IP addresses is only relevant on the local link and cannot trace the path or measure delay across multiple network segments. ARP is limited to local network resolution.

The correct tool for examining the full path of packets and identifying delays is the one that traces each hop along the route, making the first choice correct.

Question 57

 A network administrator wants to reduce broadcast traffic and segment a large network into smaller logical domains. Which approach should be used?

A) Implement VLANs
B) Increase MTU size
C) Enable Telnet
D) Use DHCP reservation

Answer: A) Implement VLANs

Explanation:

A) Creating virtual LANs allows administrators to logically group devices regardless of physical location. Broadcast traffic is contained within each VLAN, reducing congestion on other parts of the network. VLANs improve security by segmenting sensitive systems and simplify management by organizing users or devices based on function or department. They also make it easier to apply policies and control traffic flow, while maintaining a scalable and flexible network design. VLANs are a fundamental tool for controlling broadcast domains in switched environments.

B) Changing the maximum transmission unit affects packet size but does not reduce broadcast traffic or segment networks. It is unrelated to logical network organization.

C) Enabling remote command-line access facilitates management but does not influence network segmentation or traffic containment. It is a management feature rather than a network design strategy.

D) Reserving addresses ensures predictable IP assignments but does not impact broadcast domains or logically group devices. It provides configuration consistency, not traffic isolation.

Segmenting a network into logical domains to reduce broadcasts and improve control requires VLANs, making the first option correct.

Question 58

A network engineer needs to provide secure remote access for users connecting over the internet while allowing them to access internal applications. Which solution should be deployed?
A) Remote VPN
B) Public Wi-Fi
C) Static routing
D) NAT

Answer: A) Remote VPN

Explanation:

A) A Remote Virtual Private Network (VPN) is the most appropriate solution for providing secure remote access to internal network resources. A VPN establishes an encrypted tunnel between the user’s device—be it a laptop, desktop, or mobile device—and the corporate network. This encrypted tunnel ensures that all traffic traversing the untrusted internet remains confidential, cannot be intercepted by malicious actors, and preserves data integrity. By encrypting communications, the VPN mitigates risks such as packet sniffing, man-in-the-middle attacks, and unauthorized access attempts, which are particularly relevant when users connect from unsecured networks, including home Wi-Fi or public hotspots.

In addition to encryption, VPN solutions incorporate strong authentication mechanisms. Modern VPN clients often support multiple layers of authentication, including username and password combinations, digital certificates, and multi-factor authentication (MFA). MFA adds an additional security layer by requiring users to provide a second verification factor, such as a one-time passcode or biometric verification, ensuring that even if credentials are compromised, unauthorized access is prevented. This combination of encryption and authentication ensures that remote access is both secure and reliable.

VPNs also allow users to access internal applications as though they were physically present in the corporate office. Applications such as email servers, file shares, intranet portals, ERP systems, and databases can be accessed without exposing these services directly to the internet. This approach reduces the attack surface by preventing services from being publicly reachable while still providing remote users with full functionality. Furthermore, VPNs enforce secure routing policies, directing traffic through the corporate network for inspection by firewalls, intrusion detection systems, or content filters. This ensures that internal security policies are consistently applied to all remote sessions.

There are several types of VPNs, including SSL VPNs and IPsec VPNs. SSL VPNs operate over standard HTTPS ports, making them compatible with most networks and allowing access through web browsers without requiring extensive client configuration. IPsec VPNs provide robust encryption at the network layer and are commonly used for site-to-site connections but can also be deployed for remote access. Some organizations deploy a combination of both, depending on the level of security and user convenience required.

From an operational perspective, deploying a VPN is also scalable and manageable. VPN gateways can be integrated with existing authentication systems, such as LDAP or Active Directory, allowing centralized control over user permissions. Network administrators can enforce policies such as access control lists (ACLs), split tunneling, and bandwidth limits to ensure that the network remains secure and efficient. Logging and monitoring capabilities allow security teams to track VPN usage, detect anomalies, and respond to potential threats promptly.

B) Connecting through unsecured public networks, such as open Wi-Fi hotspots in cafes or airports, does not provide any encryption or access control. While convenient, public Wi-Fi exposes traffic to interception by attackers, who can capture sensitive data, redirect connections, or inject malicious content. Public Wi-Fi also does not allow direct access to internal corporate resources unless combined with a secure method such as a VPN. Relying solely on public networks for remote access would leave internal applications vulnerable to unauthorized access, data breaches, and potential malware infection.

C) Static routing defines predetermined paths for network traffic between known networks. While static routes are useful for directing packets within a trusted network infrastructure or between branch offices, they do not offer encryption, authentication, or secure tunneling capabilities. Static routing alone cannot protect traffic over the public internet, and it does not provide the necessary secure access for remote users who are connecting from outside the corporate environment. Without encryption, sensitive data such as login credentials, proprietary documents, or internal communications would be exposed to potential attackers.

D) Network Address Translation (NAT) allows private IP addresses to be mapped to public IP addresses, enabling devices within a local network to communicate with external networks such as the internet. While NAT is essential for conserving IP addresses and managing routing between private and public networks, it does not provide encryption, authentication, or secure access to internal resources. NAT by itself does not prevent eavesdropping, data tampering, or unauthorized access, meaning that relying solely on NAT for remote access would leave internal applications unprotected. NAT is a supporting technology, often used alongside firewalls and VPNs, but cannot meet the requirement for secure remote connectivity.

Implementing a remote VPN also provides additional benefits beyond security. Organizations can ensure compliance with regulatory frameworks such as GDPR, HIPAA, or PCI DSS by enforcing encrypted communications for remote workers handling sensitive data. VPNs allow consistent network policies regardless of the user’s location, helping IT teams maintain visibility and control over remote access. Furthermore, VPNs can be configured to support a variety of devices, including desktops, laptops, tablets, and mobile phones, providing flexibility for modern remote work environments.

Modern enterprise VPN solutions also support advanced features such as split tunneling, which allows users to access the corporate network while routing non-corporate traffic directly to the internet. This reduces bandwidth usage on the corporate network while maintaining security for sensitive applications. Additionally, centralized management consoles provide administrators with the ability to deploy updates, revoke access, or generate audit reports efficiently.

In a remote VPN is the only solution among the options that provides the combination of secure encrypted connectivity, authentication, and internal application access for remote users. It ensures confidentiality, integrity, and proper authentication while allowing users to operate as though they were physically connected to the corporate network. By contrast, public Wi-Fi, static routing, and NAT alone either expose traffic to risk, fail to provide secure remote access, or do not protect sensitive communications. Deploying a remote VPN is a standard best practice for secure remote work in today’s increasingly mobile and distributed enterprise environments.

 

Question 59

A network technician is troubleshooting a fiber optic link that fails intermittently. Inspection shows dirty connectors on the transceivers. Which action should be taken to resolve the issue?
A) Clean the connectors with proper fiber cleaning tools
B) Replace the switch entirely
C) Increase MTU size
D) Disable spanning tree

Answer: A) Clean the connectors with proper fiber cleaning tools

Explanation:

A) Contaminated fiber connectors introduce attenuation, reflection, and signal loss, leading to intermittent connectivity. Fiber optic cables rely on precise alignment of the core to core contact between connectors. Even microscopic particles, dust, or oil residues from human hands can cause significant signal degradation. When dirt is present on the connector end face, light signals traveling through the fiber are scattered or partially reflected back toward the transmitter. This reflection, also called back-reflection, can interfere with signal integrity, generate errors, and trigger retransmissions, which appear as intermittent connectivity issues on the network.

Cleaning the connectors with appropriate tools is the standard and most effective method for restoring optimal signal transmission. Typical cleaning tools include lint-free wipes, isopropyl alcohol, specialized fiber cleaning swabs, and cassette-based cleaning devices designed for LC, SC, ST, or MPO connectors. The process involves gently wiping or inserting the cleaning tool to remove contaminants without scratching or damaging the ferrule or core. After cleaning, the connector can be inspected using a fiber microscope to ensure that all debris has been removed, preventing residual contamination from continuing to impair the link.

Proper maintenance of fiber connections is not just a one-time fix; it is considered routine preventative care in optical networks. Regular inspection and cleaning reduce insertion loss and reflection, which are key parameters for fiber performance. Insertion loss measures the power reduction as the signal passes through the connector, while reflection quantifies the portion of light that is bounced back toward the source. By minimizing these factors, technicians can maintain high bandwidth, reduce error rates, and prevent intermittent failures that can disrupt critical applications such as VoIP, data replication, and real-time video transmission.

Additionally, network documentation often requires recording the cleaning process, noting the date, connector type, and measured optical loss before and after maintenance. This practice ensures compliance with industry standards and provides traceability for troubleshooting recurring issues. Fiber network engineers frequently include connector cleaning in their preventive maintenance schedules, especially in environments where dust, humidity, or human traffic increases the likelihood of contamination, such as data centers, industrial plants, or outdoor fiber runs.

B) Replacing the switch is unnecessary when the root cause is contamination on connectors. Optical network equipment is generally reliable, and switching hardware is rarely the cause of intermittent fiber link failures unless there is a hardware defect. Replacing the switch in response to a physical-layer signal issue would be costly, inefficient, and unlikely to resolve the problem. Understanding the distinction between physical layer issues and device failure is critical for effective troubleshooting and cost management.

C) Adjusting the maximum frame size (MTU) does not address physical-layer signal loss caused by dirty connectors. MTU settings affect how large data packets can be transmitted across a network segment but have no influence on optical signal quality. Changing MTU may prevent packet fragmentation at higher layers, but the fundamental cause of intermittent connectivity in this scenario is at the optical physical layer. Misapplying MTU adjustments would waste time and not solve the underlying problem.

D) Disabling loop-prevention mechanisms such as spanning tree does not resolve signal degradation from physical contamination. In fact, disabling spanning tree can introduce additional network risks, including broadcast storms, network loops, and overall instability. Loop prevention is a logical network configuration task, whereas fiber contamination is a physical layer problem. Confusing the two issues can lead to unnecessary downtime or more serious network problems.

In conclusion, cleaning the fiber connectors directly addresses the cause of intermittent failures. By removing contaminants, restoring proper light transmission, and inspecting the connection for residual particles, network reliability is restored. This approach is efficient, cost-effective, and aligns with best practices for fiber network maintenance. Regular cleaning, proper handling, and routine inspection are essential for sustaining high-performance optical networks.

Question 60

A technician observes that multiple devices on a subnet cannot communicate with devices on a different subnet, even though the router is correctly configured. The switches connecting the devices are all part of the same VLAN. What is the most likely cause?
A) Missing inter-VLAN routing
B) Duplicate IP addresses
C) Incorrect DHCP server
D) Wireless interference

Answer: A) Missing inter-VLAN routing

Explanation:

A) Devices in separate VLANs cannot communicate unless a router or a layer-three switch is configured to route between VLANs. Virtual Local Area Networks (VLANs) are logical segmentations of a physical network. They allow network administrators to separate traffic into isolated domains to improve security, reduce broadcast traffic, and manage resources efficiently. Although multiple switches may be physically connected, VLANs operate at layer 2 (Data Link layer) and isolate broadcast domains. Traffic from one VLAN cannot cross into another VLAN without a Layer 3 device performing routing.

Inter-VLAN routing provides the mechanism for this cross-VLAN communication. Typically, this is achieved through a router with subinterfaces, a Layer 3 switch with SVIs (Switch Virtual Interfaces), or dedicated routing equipment configured to handle multiple VLANs. Each VLAN is assigned a unique subnet, and the routing device forwards traffic between these subnets. Without inter-VLAN routing, each VLAN remains a logically isolated network segment. Consequently, devices in one VLAN can only communicate with devices in the same VLAN, explaining the connectivity problem observed in this scenario.

This type of misconfiguration is common in enterprise networks where VLANs are implemented for security or traffic management but the Layer 3 routing configuration is overlooked. Technicians must ensure that routing interfaces exist for each VLAN and that the routing device has the proper IP addresses and routes configured. Additionally, ACLs (Access Control Lists) may need to be applied to control which VLANs can communicate, preventing security breaches while still allowing legitimate traffic.

B) Duplicate IP addresses create conflicts but usually cause intermittent connectivity problems for the affected hosts, not a complete inability to communicate across VLANs. A device with a duplicate IP address may experience dropped packets or ARP conflicts, but other devices within the same subnet can typically communicate normally. This does not explain total isolation between logical segments, making this option less likely.

C) Misconfigured DHCP servers affect client connectivity by potentially assigning incorrect IP addresses, gateways, or subnet masks. While DHCP problems can prevent some devices from joining the network, they do not inherently stop properly configured devices from communicating across VLANs if routing exists. Therefore, DHCP misconfiguration alone would not account for the observed isolation between subnets.

D) Wireless interference affects connectivity for wireless clients but is irrelevant in a wired VLAN environment where switches are physically and logically connected. Wired devices do not rely on radio frequency transmission, and interference would not create the logical separation seen in VLAN misconfigurations.

The lack of inter-VLAN routing is the fundamental reason devices in separate logical segments cannot communicate. Recognizing the distinction between layer 2 isolation and layer 3 routing is critical for troubleshooting. Network administrators often use tools such as traceroute, ping, or VLAN database commands to verify routing configuration and confirm that SVIs or routing interfaces are active. Once inter-VLAN routing is properly configured, devices in different VLANs can communicate while still maintaining the benefits of broadcast domain isolation and network segmentation.

Correctly configuring inter-VLAN routing not only resolves communication issues but also enhances network design by ensuring scalability, security, and performance. Proper routing allows for more efficient use of network resources and reduces unnecessary broadcast traffic. Additionally, documenting VLAN IDs, IP subnets, and routing interfaces helps prevent configuration errors in the future, allowing technicians to quickly identify and resolve connectivity issues.