CompTIA N10-009 - CompTIA Network+ Certification Exam

For a secure 802.1X design that includes BYOD access to a trusted wireless network, the engineer should implement NAC (Network Access Control). In the Network+ (N10-009) objectives, 802.1X provides authentication (commonly via EAP to a RADIUS server), but NAC expands this by enforcing policy-based access decisions—such as device posture checks, user/device identity validation, and dynamic assignment to the appropriate VLAN/role. With BYOD, the organization often needs to confirm whether devices meet requirements (OS version, encryption, security software) and then grant the correct level of access (full, limited, or quarantine/remediation). NAC is the architecture that ties these controls together in a scalable way for wireless networks.

An ACL can restrict traffic after a device connects, but it doesn’t perform authentication/posture assessment. MAC filtering is weak because MAC addresses can be spoofed and it does not provide strong identity assurance. Port security is mainly a wired switch control (limiting MAC addresses per port) and is not the right control set for secure BYOD wireless access. NAC best matches the requirement of secure, policy-driven 802.1X BYOD access.

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The correct answer is Shielded Twisted Pair (STP). According to the CompTIA Network+ N10-009 objectives, intermittent connectivity issues—especially in environments like hospitals—are often caused by electromagnetic interference (EMI) from medical imaging equipment, power systems, and other electronic devices. These environments are electrically noisy and can disrupt standard copper Ethernet cabling.

STP cabling is specifically designed to mitigate EMI by incorporating shielding around the twisted pairs. This shielding reduces external interference and improves signal stability without requiring a complete redesign of the network. Importantly, STP is significantly less expensive than deploying fiber-optic solutions while still being highly effective in environments prone to interference.

Single-mode fiber would eliminate EMI entirely, but it is far more costly due to specialized cabling, transceivers, and installation requirements. Twinaxial cable is typically used for short-distance, high-speed data center connections and is not appropriate for workstation connectivity. Spanning Tree Protocol (STP) is a Layer 2 loop-prevention protocol and has nothing to do with physical connectivity or interference issues.

The Network+ objectives stress choosing solutions that balance effectiveness, cost, and environmental suitability. In this case, upgrading to shielded twisted pair cabling provides the most practical and cost-effective resolution for intermittent connectivity in a hospital imaging environment.

The key difference is that an Intrusion Prevention System (IPS) is installed in line with network traffic, allowing it to actively block threats. In contrast, an Intrusion Detection System (IDS) only monitors and alerts without actively blocking traffic.

Breakdown of Options:

A. An IPS needs to be installed in line with traffic and an IDS does not. ✅ Correct answer. IPS actively prevents threats, while IDS only detects them.

B. An IPS is signature-based and an IDS is not. – False, both can use signature-based detection.

C. An IPS is less susceptible to false positives than an IDS. – False, both can produce false positives, depending on configurations.

D. An IPS requires less administrative overhead than an IDS. – False, IPS requires more administrative effort due to real-time blocking decisions.

The switch with the lowest STP priority becomes the root bridge.In the given table, core-sw01 has the lowest priority value of 24576. Therefore, it will be elected as the root bridge in the Spanning Tree Protocol topology.

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

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

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

In the router route selection process, the first priority is the longest prefix match, also known as prefix length. According to CompTIA Network+ (N10-009) routing concepts, routers examine the destination IP address in the packet and compare it to entries in the routing table. When multiple routes exist, the router selects the route with the most specific match, meaning the route with the longest subnet mask (largest number of matching bits). For example, a /30 route is preferred over a /24, and a /24 is preferred over a /16 if all match the destination.

Only after the longest prefix match is determined do other factors come into play. Administrative distance (AD) is used to determine which routing source is more trustworthy when the same network is learned from different routing protocols (e.g., OSPF vs. RIP). Metric is then used within the same routing protocol to determine the best path (e.g., hop count, cost, bandwidth). A default route (0.0.0.0/0) is used only when no more specific match exists.

Therefore, prefix length is always evaluated first in route selection.

802.1X provides port-based network access control that requires authentication before a switch port grants full network access. It uses a supplicant (client), an authenticator (switch/AP), and an authentication server (commonly RADIUS) to validate credentials or certificates. This directly supports the requirements: it reduces spoofing compared with MAC-based controls because authentication can be identity- and certificate-based rather than relying on easily forged MAC addresses; it is centrally managed through AAA infrastructure and policy (users/devices/groups); and it produces auditable logs via the authentication server and network devices, enabling accountability and investigation. Network+ security objectives emphasize AAA, NAC, and strong access controls for both wired and wireless networks. MAC filtering and basic port security rely largely on MAC addresses and are susceptible to spoofing; they also tend to be harder to manage at scale and provide weaker centralized auditing. ACLs control traffic flows but do not authenticate endpoints at the port level, so they cannot ensure “only authenticated devices” can connect. Therefore, 802.1X is the technology that best meets all stated requirements.

The correct answer is /25, which is the appropriate subnet mask for dividing an existing Class C network into two equal subnets. According to the CompTIA Network+ N10-009 objectives, subnetting is a core networking concept used to improve network segmentation, performance, and security.

A Class C network uses a default subnet mask of /24 (255.255.255.0), which provides 256 total addresses (254 usable). To split this network into two sections, the administrator must borrow one host bit from the last octet. Borrowing one bit results in a /25 subnet mask (255.255.255.128). This creates two subnets, each with 128 total addresses (126 usable)—an ideal solution for separating two departments such as finance and marketing.

A /24 would not create any segmentation, as it represents the original single network. A /26 would create four subnets, and a /27 would create eight subnets, both of which exceed the requirement of only two sections and unnecessarily reduce the number of available host addresses per subnet.

The Network+ objectives emphasize selecting subnet masks based on organizational requirements, balancing the number of subnets with sufficient host capacity. In this scenario, /25 is the most efficient and correct choice.

VLAN hopping is an attack where an attacker crafts packets with multiple VLAN tags, allowing them to traverse VLAN boundaries improperly. This can result in gaining unauthorized access to network segments that are supposed to be isolated. The other options do not involve the use of multiple network tags. MAC flooding aims to overwhelm a switch’s MAC address table, DNS spoofing involves forging DNS responses, and ARP poisoning involves sending fake ARP messages.

On Core-SW01, the ports are configured with LACP (mode active) for link aggregation. On Core-SW02, the ports are configured as independent trunks, not as part of an LACP group. Because of this mismatch, LACP cannot form the bundle, and the aggregated ports on SW01 will go into a suspended state.

A. CRC errors suggest cabling or signal integrity issues, not config mismatch.

B. Error disabled occurs when a violation (like BPDU guard or port security) disables the port, not LACP mismatch.

C. Administratively down indicates a shutdown command, not the case here.

References (CompTIA Network+ N10-009):

Domain: Network Troubleshooting — Port-channel/LACP configuration issues, interface states.

An access point (AP) provides users with an extended footprint that allows connections from multiple devices within a designated Wireless Local Area Network (WLAN).

Router: Typically used to connect different networks, not specifically for extending wireless coverage.

Switch: Used to connect devices within a wired network, not for providing wireless access.

Access Point (AP): Extends wireless network coverage, allowing multiple wireless devices to connect to the network.

Firewall: Primarily used for network security, controlling incoming and outgoing traffic based on security rules, not for providing wireless connectivity.

Network References:

CompTIA Network+ N10-007 Official Certification Guide: Explains the roles and functions of network appliances, including access points.

Cisco Networking Academy: Provides training on deploying and managing wireless networks with access points.

Network+ Certification All-in-One Exam Guide: Covers network devices and their roles in creating and managing networks.

A cable tester is a tool that can help identify issues with the physical cabling, such as breaks or improper terminations, which may prevent the access point from reaching the internet.

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An incorrect pinout on the patch cable could prevent network connectivity due to mismatched wiring. Even if the cables are the correct length and type, a pinout issue can cause continuity problems and prevent data transmission. Proper crimping with the correct pinout is essential for network cables to function. (Reference: CompTIA Network+ Study Guide, Chapter on Network Media and Topologies)

When an organization moves its DNS servers to new IP addresses, the NS (Name Server) records must be updated. The NS record defines which DNS servers are authoritative for a domain. Ifthese records still point to the old IP addresses, clients will continue to query the outdated servers, leading to connectivity issues.

Breakdown of Options:

A. AAAA – This record maps a domain name to an IPv6 address. Since the issue is with DNS resolution, not IP versioning, this is incorrect.

B. CNAME – A CNAME (Canonical Name) record is used for domain aliasing, not for defining authoritative name servers.

C. MX – Mail Exchange (MX) records direct email traffic to the correct mail server, which does not impact general website accessibility.

D. NS – Correct answer. NS records must be updated to reflect the new authoritative DNS servers.