Pass the CompTIA CompTIA Network+ N10-009 Questions and answers with CertsForce

A /23 subnet provides 512 total addresses, of which 510 are usable (subtracting 2 for network and broadcast addresses). This would satisfy the need for 255 additional addresses.

The correct answer is D. SVI. When traffic must move between multiple VLANs, some Layer 3 function has to exist so each VLAN can have a gateway. A Switched Virtual Interface (SVI) provides a logical Layer 3 interface for a VLAN and is commonly used to support inter-VLAN communication. In exam wording, when the question points to communication across multiple VLANs, the important idea is that each VLAN needs a Layer 3 presence.

The other answer choices do not fit this requirement. Static routing is used to define network paths, but it does not by itself create the VLAN gateway interfaces needed for inter-VLAN traffic. NAT translates addresses, usually for internet access, not for switching between local VLANs. Full duplex is a link operation mode and has nothing to do with routing traffic between VLANs.

The phrase “communicating over multiple VLANs” is the key clue. VLANs are separate broadcast domains, so devices in different VLANs cannot communicate without Layer 3 intervention. Among the choices given, SVI is the only answer that provides that Layer 3 function in a switched environment. That is why D is the best answer.

Comprehensive and Detailed Explanation (paraphrased, aligned to N10-009):

An evil twin is a malicious wireless access point that impersonates a legitimate SSID. Once victims connect, the attacker can intercept and manipulate traffic, performing an on-path (man-in-the-middle) attack—capturing credentials, injecting content, or downgrading encryption.

B. DDoS overwhelms services with traffic; it’s not the typical follow-on from clients joining a rogue AP.

C. ARP spoofing is another way to become on-path on wired segments, but with an evil twin, the wireless association itself enables the on-path position.

D. Phishing is social engineering; while an evil twin could be used to present fake portals, the primary technical posture after connection is on-path.

References (CompTIA Network+ N10-009):

Domain: Network Security — Wireless threats (rogue APs/evil twins), traffic interception, on-path attacks.

===========

Band steering allows wireless access points to automatically direct capable devices to the 5GHz band, which typically has higher throughput and less interference than the 2.4GHz band, improving performance. The document confirms:

“Band steering helps balance wireless client loads by steering dual-band capable devices to the 5GHz band, which offers higher speeds and less channel congestion than 2.4GHz.”

Spanning Tree Protocol (STP) is designed to detect and prevent Layer 2 loops by blocking redundant paths. If loops are possible in the design, enabling STP ensures network stability.

B. Port security controls endpoint MAC addresses, not loops.

C. Speed limits address bandwidth, not loop prevention.

D. 802.1Q tagging allows VLAN separation but does not resolve loops.

References (CompTIA Network+ N10-009):

Domain: Network Operations — Loop prevention, spanning tree, switch design.

The correct answer is B. MAC filtering. MAC filtering is a straightforward method of restricting network access by allowing only specific device MAC (Media Access Control) addresses to connect to a wireless network. In a small, stable environment with fewer than ten devices and no expected changes, this approach is simple to implement and manage.

Each network interface card (NIC) has a unique MAC address, and wireless access points can be configured with a whitelist of approved addresses. Devices not on the list are denied access, effectively limiting connectivity to only authorized laptops. This aligns with CompTIA Network+ guidance for basic access control mechanisms in small or low-complexity networks.

Other options are less suitable in this scenario. ACLs (Access Control Lists) are typically used on routers and switches to control traffic flow based on IP addresses or protocols, not specifically device access to a wireless network. NAC (Network Access Control) provides more advanced authentication and posture assessment but is more complex and unnecessary for a small, static environment. Trusted zones refer to network segmentation concepts rather than device-level access control.

Thus, MAC filtering provides the simplest and most appropriate solution.

The correct choice is D. netstat because the display shown is a classic list of active TCP sessions, including the protocol, local address, remote address, and the connection state such as ESTABLISHED and TIME_WAIT. That is exactly the kind of information a technician checks when trying to see what connections a workstation currently has open.

The distractors do different jobs. nslookup and dig are DNS utilities. They help query name resolution records, but they do not list active client sessions. nmap is mainly used to scan hosts and ports across the network, usually to discover services or assess exposure on target systems. It does not normally produce a local session table in this format.

For Network+ purposes, this falls under troubleshooting with command-line tools. When the goal is to inspect current sessions on the local device and confirm whether a port is open, listening, or already connected, netstat is the expected command. The wording “currently established from a client device” is the clue that matters most. The question is not asking what ports exist on a remote server; it is asking what active connections are present on the machine itself. That makes netstat the best fit.

EIGRP(Enhanced Interior Gateway Routing Protocol) supports bothIPv4 and IPv6. While OSPFv3 is specific to IPv6 and RIPv2 only supports IPv4, EIGRP was extended to handle dual-stack environments efficiently.

NAT (Network Address Translation) allows multiple private IP addresses to share a single public IP when accessing the internet. This conserves public IPs and provides basic security by hiding internal addresses.

B. BGP is a routing protocol.

C. OSPF is a link-state IGP.

D. FHRP provides redundant gateways, not IP sharing.

References (CompTIA Network+ N10-009):

Domain: Networking Concepts — NAT, PAT, private-to-public IP mapping.

The netstat command provides information about network connections, routing tables, interface statistics, masquerade connections, and multicast memberships. Running netstat on the server can help the administrator verify that the web server process is listening on the expected port (e.g., port 80 for HTTP or port 443 for HTTPS) and that there are no issues with network connections. This is a crucial first step in diagnosing why the web server is not accessible via a browser.References: CompTIA Network+ study materials. ​

The three-tier hierarchical model in network design consists of three layers: access, distribution, and core. The access layer is where devices like PCs and printers connect to the network. The distribution layer aggregates the data received from the access layer switches before it is transmitted to the core layer, which is responsible for high-speed data transfer and routing. This approach improves scalability and performance in larger networks. References: CompTIA Network+ Exam Objectives and official study guides.

The MPO (Multi-fiber Push On) connector is designed to handle multiple fiber strands in a single connector, and it is commonly used with high-density transceivers like QSFP (Quad Small Form-factor Pluggable).

QSFP can support up to four channels (hence " quad " ), and MPO connectors can interface multiple fibers (e.g., 8, 12, 24), making them ideal for 40Gbps or 100Gbps deployments.

RJ45 (A) is used for Ethernet over copper.

ST (B) and LC (C) are single-fiber connectors — they don ' t support the multi-fiber needs of QSFP setups.

✅ Therefore, MPO is the correct connector type for this use case.

An 802.11ac wireless bridge is the most practical solution to connect two nearby buildings without trenching or laying physical cable. It provides high-speed, point-to-point connectivity using directional antennas.

A. Multimode fiber is effective but expensive and typically limited to 500 meters or less.

C. Cat 6 copper is only rated for up to 100 meters — not viable for a street-wide distance.

D. Loopback adapter is a troubleshooting tool, not for network extension.

???? Reference:

CompTIA Network+ N10-009 Official Objectives: 1.3 – Compare and contrast various network topologies, types, and technologies.

In the CompTIA Network+ (N10-009) troubleshooting methodology, the step that follows verifying full system functionality (confirming the issue is resolved and validating with the user/requirements) is documenting findings, actions, and outcomes. Documentation is a required closing step because it captures what the original symptoms were, what troubleshooting steps were performed, what root cause was identified (if found), what remediation was applied, and what validation confirmed success. This record supports operational continuity by enabling faster resolution if the issue recurs, improving knowledge transfer across teams, and meeting organizational change-control or compliance requirements.

The other options fall in different parts of the methodology. Attempting to replicate the problem is typically performed earlier—after identifying symptoms and before or during isolation—to confirm the issue and help narrow scope. Implementing the plan occurs before verification; you implement the selected solution or escalation plan and then test/verify. Escalating the issue occurs when the technician lacks access, expertise, time, or evidence to proceed, and it can happen during troubleshooting—but it is not the standard step that comes after verifying resolution.