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

Understanding Spanning Tree Protocol (STP):

STP is used to prevent network loops in Ethernet networks by creating a spanning tree that selectively blocks some redundant paths.

Default Priority Value:

Bridge Priority: STP uses bridge priority to determine which switch becomes the root bridge. The default bridge priority value for most switches is 32768.

Priority Range: The bridge priority can be set in increments of 4096, ranging from 0 to 61440.

Configuration and Verification:

When deploying a new switch, the network administrator can verify the bridge priority using commands such as show spanning-tree to ensure it is set to the default value of 32768.

Comparison with Other Values:

4096 and 8192: Lower than the default priority, indicating these would be manually configured for higher preference.

36684: A non-standard value, likely a result of specific configuration changes.

SNMPv3 (Simple Network Management Protocol version 3) provides device monitoring with authentication and encryption. This enhances network visibility and security by ensuring that monitoring data is securely transmitted and access to network devices is authenticated.

Authentication: SNMPv3 includes robust mechanisms for authenticating users accessing network devices.

Encryption: It provides encryption to protect the integrity and confidentiality of the data being transmitted.

Network Management: SNMPv3 allows for detailed monitoring and management of network devices, ensuring better control and security.

Network References:

CompTIA Network+ N10-007 Official Certification Guide: Covers SNMP versions, their features, and security enhancements in SNMPv3.

Cisco Networking Academy: Provides training on implementing and securing SNMP for network management.

Network+ Certification All-in-One Exam Guide: Explains the benefits and security features of SNMPv3 for network monitoring.

Port 22 is used for SFTP (Secure File Transfer Protocol) and SCP (Secure Copy Protocol), which encrypt file transfers using SSH (Secure Shell). This ensures data is transmitted securely over the network.

•Why not the other options?

•Port 69 (B) – TFTP (Trivial File Transfer Protocol): Transfers files but is not secure (no encryption).

•Port 80 (C) – HTTP: Used for web traffic, not for file transfer.

•Port 3389 (D) – RDP (Remote Desktop Protocol): Used for remote desktop access, not file transfer.

If a network appliance fails to start, standard remote access methods like SSH won ' t work. Instead, Out-of-Band (OOB) management provides a dedicated access path (e.g., a console port or iDRAC/iLO), allowing administrators to troubleshoot devices even when the network is down.

Breakdown of Options:

A. Crash cart – A physical monitor/keyboard setup, not a remote solution.

B. Jump box – A hardened system used for secure remote access but requires the device to be operational.

C. Secure Shell (SSH) – Requires the device to be fully booted and network-connected.

D. Out-of-band management – ✅ Correct answer. Provides independent access for troubleshooting failed network devices.

These four terms—avoidance, acceptance, mitigation, and transfer—are strategies used in risk management.

From Andrew Ramdayal’s guide:

“Risk in security refers to the potential for loss, damage, or destruction of assets or data due to a threat exploiting a vulnerability. Risk management strategies include avoidance, acceptance, mitigation, and transfer.”

Secure Shell (SSH) is a protocol used to securely access remote devices over an unsecured network. It provides encrypted command-line access and is a lightweight and secure method of remote administration.

A. Site-to-site VPN connects entire networks, not just a single host.

B. Telnet is not secure; it transmits data (including credentials) in plaintext.

C. Console access is direct via serial cable, not remote.

???? Reference:

CompTIA Network+ N10-009 Official Objectives: 2.6 – Configure and troubleshoot remote access.

To monitor the contents of data (i.e., inspect the actual packets/frames and their payloads) moving between networks, the administrator should use port mirroring (also called SPAN on some platforms). Port mirroring copies traffic from one or more switch ports (or VLANs) to a designated monitoring port where a packet analyzer/IDS sensor can capture and inspect the traffic in detail. This aligns with Network+ (N10-009) security and monitoring concepts that distinguish between packet-level visibility and higher-level summaries or logs. If the requirement is explicitly to monitor “contents,” you need a method that provides full packet capture capability, not just metadata.

Flow data (e.g., NetFlow) provides summarized metadata—who talked to whom, how much, ports, and timestamps—but not full payload contents. Syslog entries are device/application-generated logs and only show events a device chooses to report; they don’t provide full data content visibility. SNMP traps are alerts about status changes (interfaces, thresholds, etc.) and similarly do not include traffic contents. Therefore, port mirroring is the correct monitoring method for inspecting data contents in transit.

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For 45 hosts, the minimum subnet size must allow at least 46 usable addresses (1 each for network and broadcast addresses).

A /26 subnet provides 64 addresses, 62 usable — suitable.

A /27 subnet gives only 30 usable — insufficient.

A /25 offers 126 usable — more than needed.

A /28 provides just 14 — too small.

So, the most efficient subnet with minimal wastage is /26.

From Andrew Ramdayal’s guide:

“When designing subnets, always choose the smallest subnet mask that still accommodates all hosts. A /26 provides 62 usable host addresses, suitable for networks with about 50 hosts.”

Shoulder surfing is a social engineering attack where attackers observe someone’s private information by looking over their shoulder or using tools like cameras to capture input.

From Andrew Ramdayal’s guide:

“Shoulder surfing is the act of watching someone enter confidential information, such as PINs or passwords, often using direct line-of-sight or surveillance equipment.”

The correct answer is D: Increase the scope to 10.8.100.50 – 10.8.100.175. According to the CompTIA Network+ N10-009 objectives, proper DHCP scope configuration is essential to ensure all hosts can obtain valid IP addresses and communicate beyond their local segment.

In this scenario, the DHCP scope is configured for 10.8.100.50 through 10.8.100.150, while a reservation range exists from 10.8.100.151 through 10.8.100.175. The network scan shows that IP addresses up to 10.8.100.175 are already in use. This indicates that some devices are either statically assigned addresses outside the active scope or are failing to receive valid DHCP leases, causing the new laptops to communicate only with each other—often a sign of APIPA or improper addressing.

To ensure full connectivity, the DHCP scope must be expanded to include the entire range of addresses that are actively in use, including the reserved addresses. Option D correctly extends the scope to 10.8.100.175 without overlapping lower addresses that may be statically assigned or intentionally excluded.

The Network+ objectives emphasize avoiding address conflicts and ensuring DHCP scopes align with real-world network usage. Expanding the scope to include all valid addresses ensures that all laptops can obtain proper IP configuration, default gateway information, and full network connectivity.

Port security is a Layer 2 security feature that restricts the number of devices connecting to a network switch port. It helps prevent unauthorized devices, such as an unmanaged switch, from being connected to the network.

How Port Security Works:

Limits the number of MAC addresses that can connect to a port.

Can shut down or restrict the port if an unauthorized device is detected.

Prevents users from plugging in unauthorized networking equipment (e.g., unmanaged switches, hubs).

Incorrect Options:

A. Screened Subnet: A screened subnet (DMZ) is used for isolating external-facing servers, not for controlling unauthorized network connections.

B. 802.1X: Provides authentication for devices but requires a RADIUS server, which is a more complex solution than port security.

C. MAC Filtering: Controls which MAC addresses can connect but is difficult to manage and can be spoofed.

A Change Advisory Board (CAB) reviews and approves network changes. Before approval, they need a detailed action plan outlining the change, potential impacts, and mitigation strategies.

A Plan of Action includes risk assessments, rollback procedures, and deployment steps, which are critical for decision-making.

? Reference: CompTIA Network+ (N10-009) Official Study Guide – Section: Network Troubleshooting Methodologies

The troubleshooting methodology requires following a logical sequence. In this case, the engineer has already identified the problem (firewall blocking traffic) and confirmed it with evidence (packet captures). The next appropriate step is to create a plan of action that outlines how to resolve the issue and considers potential effects.

A. Implementing the solution is premature without planning.

C. Establishing a theory was already completed during problem isolation.

D. Documentation occurs after resolution.

By carefully planning, the engineer ensures that corrective action won’t cause additional outages or security issues, especially given the scale of the incident (3,000 users).

References (CompTIA Network+ N10-009):

Domain: Network Troubleshooting — Troubleshooting methodology, plan of action.