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

The CompTIA Troubleshooting Methodology states that after testing the theory, the next step is to establish a plan of action to resolve the issue.

Troubleshooting Steps:

Identify the problem.

Establish a theory of probable cause.

Test the theory to determine the cause.

Establish a plan of action and implement the solution. ✅ (Correct step)

Verify full system functionality.

Document findings, actions, and outcomes.

Breakdown of Options:

A. Verify full system functionality – Happens after implementing the solution.

B. Document the findings and outcomes – Final step, happens after resolving the issue.

C. Establish a plan of action – ✅ Correct answer. Comes immediately after confirming the cause.

D. Identify the problem – First step, already completed.

ESP (Encapsulating Security Payload) is an IPsec protocol that provides encryption, integrity, and authentication for data inside a VPN tunnel. It ensures that all tunneled traffic is encrypted.

B. SSH secures remote terminal sessions, not site-to-site VPN tunnels.

C. GRE (Generic Routing Encapsulation) provides encapsulation but does not encrypt data.

D. IKE (Internet Key Exchange) negotiates keys and establishes the IPsec tunnel but does not encrypt the payload itself.

References (CompTIA Network+ N10-009):

Domain: Network Security — VPN protocols, IPsec (AH vs. ESP), encryption in transit.

A Distributed Denial of Service (DDoS) attack leverages multiple computers or bots (botnet) to flood a target system with requests, overwhelming its resources and making it unavailable to legitimate users. This is a common tactic used by attackers to disrupt services. The document explains:

“A DDoS (Distributed Denial of Service) attack involves multiple computers (often called bots) simultaneously sending requests to a single resource, overwhelming the system and causing a denial of service to legitimate users.”

The requirement is to support over 300 hosts. The subnet mask 255.255.254.0 (or /23) provides 512 addresses, 510 of which are usable — ideal for around 300 devices.

255.255.0.0 (/16) provides too many addresses.

255.255.192.0 (/18) gives 16384 addresses — overkill.

255.255.255.254 is invalid for host assignments (only 2 addresses, 0 usable).

From Andrew Ramdayal’s guide:

“To support 300 hosts, a /23 subnet (255.255.254.0) offers 510 usable addresses — the most efficient choice without excessive overhead.”

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

In a spine–leaf architecture, endpoints (including servers, firewalls, and WAN/edge routers) connect to leaf switches. Leaf switches then uplink to spine switches; spine switches do not have endpoints connected directly to them. Therefore, a WAN router (an external/edge device) should connect to the leaf layer—often specifically to a “border leaf” that handles external connectivity.

Why not B. Core or D. Spine? In spine–leaf, “core” isn’t a formal layer, and spines are designed only to interconnect leafs, not to terminate endpoints.

Why not A. Access? “Access” is a term from the traditional three-tier model (access–distribution–core). In modern spine–leaf language, the analogous layer for endpoint attachment is the leaf.

References (CompTIA Network+ N10-009):

Domain: Network Infrastructure — Data center and campus architectures (spine–leaf vs. three-tier), roles of leaf/spine, WAN/edge connectivity points.

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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.”

AnAccess Control List (ACL)configured on theedge firewallis the correct and most effective solution tofilter inbound traffic. The administrator can allow TCP port 443 (HTTPS) and deny all other traffic. This is a classic firewall configuration for securing public-facing servers.

802.1Q tagging, also known as VLAN tagging, is used to identify VLANs on a trunk link between switches. This allows the switches to transfer data for multiple VLANs (or networks) over a single physical connection. This method ensures that traffic from different VLANs is properly separated and managed across the network.References: CompTIA Network+ study materials.

Band steering is a feature in wireless networks that encourages dual-band capable devices to connect to the 5GHz band instead of the 2.4GHz band.

Why Band Steering?

The 5GHz band supports higher speeds and less interference compared to 2.4GHz.

If a device supports both bands, the access point (AP) can "steer" it to connect to 5GHz instead of 2.4GHz.

This helps ensure users always connect to the fastest available network.

Incorrect Options:

B. Disabling the 5GHz SSID: Would force devices onto 2.4GHz, which is slower and more congested.

C. Adding a Captive Portal: Used for guest authentication, not for speed optimization.

D. Configuring MAC Filtering: Used for security, not for optimizing network speed.

WPA3-Enterprise provides strong security and supports authentication using domain identities through a RADIUS server and 802.1X authentication. This is the best choice for a corporate environment requiring user-based authentication.

WPA3-Enterprise Benefits:

Uses 802.1X with EAP (Extensible Authentication Protocol) to authenticate users via a directory service (e.g., Active Directory).

Eliminates shared passwords (PSK) for authentication.

Provides strong encryption and resistance to brute-force attacks.

Incorrect Options:

A. Enable MAC Security:

MAC filtering is not secure because MAC addresses can be spoofed.

B. Generate a PSK for Each User:

Pre-shared keys (PSK) are used in WPA-Personal, not in an enterprise setting.

Does not scale well in corporate environments.

C. Implement WPS:

Wi-Fi Protected Setup (WPS) is a vulnerable security method meant for home users.

Not suitable for enterprise authentication.

An API (Application Programming Interface) is the best choice when a development team needs to integrate a device’s reporting data directly into custom software. In Network+ (N10-009) objectives, network operations commonly include device management, monitoring, and automation, and APIs are a key method for programmatic access to operational data (often via REST/HTTPS with structured formats like JSON). This enables the internal support application to pull dashboards, health metrics, events, configuration details, and reporting outputs in a controlled, developer-friendly way.

SNMPv2c is primarily used for network monitoring and polling counters/alerts, but it is less secure (community strings) and is not as flexible for modern application integration as an API. A MIB is not a data-access “feature” by itself; it’s the schema/definitions SNMP uses to describe managed objects. A SIEM is a separate security analytics platform that collects and correlates logs/events—useful for security operations, but not the direct interface a custom support tool would typically call to retrieve device reporting data.

SSH (Secure Shell) is a cryptographic network protocol that enables secure remote management and operation of network devices, including routers and switches. SSH encrypts traffic, making it more secure than alternatives like Telnet, which sends data in plaintext. The document states:

“SSH (Secure Shell) is the recommended protocol for secure, interactive remote management of network devices. It provides a secure channel over an unsecured network by encrypting the traffic between the administrator’s workstation and the managed device.”

A jump box is a hardened, isolated system that provides secure access to critical infrastructure devices like routers and firewalls.

The best answer is SNMP (Simple Network Management Protocol). SNMP enables monitoring of network devices (routers, switches, firewalls, servers) and provides performance data such as CPU usage, bandwidth utilization, and interface status. In this scenario, if SNMP monitoring had been in place, administrators would have received alerts that the router was overutilized before customers noticed outages.

A. Packet capture (e.g., Wireshark) is useful for deep troubleshooting but is reactive, not proactive, and not scalable for continuous monitoring.

C. Syslog collects log messages but generally does not provide proactive resource utilization metrics. It is complementary but not the best fit for this problem.

D. SIEM aggregates logs and security events for analysis, but the primary requirement here is performance and availability monitoring.

By implementing SNMP monitoring (and potentially integrating it with a network monitoring tool such as Nagios, PRTG, or SolarWinds), the organization can track utilization trends, set thresholds, and automatically generate alerts, thereby preventing downtime from going unnoticed.

References (CompTIA Network+ N10-009):

Domain: Network Operations — SNMP monitoring, proactive network performance management.

Bottlenecking occurs when a device in the network (such as an IPS) cannot process traffic efficiently, resulting in a dramatic drop in throughput. The significant difference between the firewall's speed (48.8 Mbps down) and the end-user devices’ speeds (4.8 - 5.2 Mbps down) indicates a bottleneck caused by the IPS.

•Why not the other options?

•Packet loss (A) – Would typically cause connection timeouts, not just slow speeds.

•Channel overlap (C) – Affects only wireless networks, but the wired desktop is also experiencing slow speeds.

•Network congestion (D) – Would show fluctuations in both upload and download speeds, but upload speeds remain unaffected.