N10-009 CompTIA Network+ Certification Exam Free Practice Exam Questions (2025 Updated)

A hybrid cloud deployment model is the best choice for the CTO's requirements. It allows the organization to run key services from the on-site data center while leveraging the cloud for enterprise services. This approach provides flexibility, scalability, and cost savings, while also minimizing disruptions to users by keeping critical services local. The hybrid model integrates both private and public cloud environments, offering the benefits of both.References: CompTIA Network+ study materials and cloud computing principles.

When working with fiber optic cables, one common issue is that the transmit (TX) and receive (RX) fibers might be reversed. The first step in troubleshooting should be to reverse the fibers at one end to ensure they are correctly aligned (TX to RX and RX to TX). This is a simple and quick step to rule out a common issue before moving on to more complex troubleshooting.References: CompTIA Network+ study materials.

Introduction to Subinterfaces:

Subinterfaces are logical interfaces created on a single physical interface. They are used to enable a router to support multiple networks on a single physical interface.

Use Case for Subinterfaces:

Subinterfaces are commonly used in scenarios where VLANs are implemented. A router with a single physical LAN port can be configured with multiple subinterfaces, each associated with a different VLAN.

This setup allows the router to route traffic between different VLANs.

Example Configuration:

Consider a router with a single physical interface GigabitEthernet0/0 and two VLANs, 10 and 20.

interface GigabitEthernet0/0.10

encapsulation dot1Q 10

ip address 192.168.10.1 255.255.255.0

!

interface GigabitEthernet0/0.20

encapsulation dot1Q 20

ip address 192.168.20.1 255.255.255.0

The encapsulation dot1Q command specifies the VLAN ID.

Explanation of the Options:

A. A router with only one available LAN port: This is correct. Subinterfaces allow a single physical interface to manage multiple networks, making it essential for routers with limited physical interfaces.

B. A firewall performing deep packet inspection: Firewalls can use subinterfaces, but it is not a requirement for deep packet inspection.

C. A hub utilizing jumbo frames: Hubs do not use subinterfaces as they operate at Layer 1 and do not manage IP addressing.

D. A switch using Spanning Tree Protocol: STP is a protocol for preventing loops in a network and does not require subinterfaces.

Conclusion:

Subinterfaces provide a practical solution for routing between multiple VLANs on a router with limited physical interfaces. They allow network administrators to optimize the use of available hardware resources efficiently.

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.

When a switch is improperly connected to a network, it can cause widespread connectivity issues, especially if there’s a misconfiguration in VLAN settings. A Native VLAN mismatch occurs when two switches connected via a trunk link have different native VLANs configured for untagged traffic. This can cause traffic to be sent to the wrong VLAN or dropped, resulting in connectivity loss for users.

Scenario Analysis: The intern likely connected the switch without ensuring that the trunk port’s native VLAN matched the existing network configuration. This is a common issue in Cisco-based networks when trunk links are misconfigured.

Why not VTP update? VLAN Trunking Protocol (VTP) updates propagate VLAN configurations across switches. While a VTP misconfiguration could cause issues, it’s less likely to immediately disrupt connectivity for many users unless the VTP server deleted critical VLANs, which is not implied here.

Why not Port security issue? Port security restricts access based on MAC addresses, typically affecting individual ports, not causing widespread outages.

Why not LLDP misconfiguration? Link Layer Discovery Protocol (LLDP) is used for device discovery, and misconfiguration is unlikely to cause a broad loss of connectivity.

A full-tunnel VPN routes all of a user's network traffic through the corporate network. This means that the organization can inspect all network traffic for security and compliance purposes, as all data is tunneled through the VPN, allowing for comprehensive monitoring and inspection.References: CompTIA Network+ study materials.

Spanning Tree Protocol (STP) uses bridge priority values to determine the root bridge in a switched network topology. Correctly configuring bridge priority helps in maintaining a loop-free and efficient network. The document explains:

“Spanning Tree Protocol (STP) uses bridge priority values to determine which switch will be the root bridge, ensuring loop prevention and efficient path selection within the network.”

Understanding 2.4GHz Interference:

The 2.4GHz frequency range is commonly used by many devices, including Wi-Fi, Bluetooth, and various industrial equipment. This can lead to interference and degraded performance.

Mitigation Strategies:

5GHz Frequency:

The 5GHz frequency band offers more channels and less interference compared to the 2.4GHz band. Devices operating on 5GHz are less likely to encounter interference from other devices, including industrial equipment.

Non-overlapping Channels:

In the 2.4GHz band, using non-overlapping channels (such as channels 1, 6, and 11) can help reduce interference. Non-overlapping channels do not interfere with each other, providing clearer communication paths for Wi-Fi signals.

Why Other Options are Less Effective:

Mesh Network: While useful for extending network coverage, a mesh network does not inherently address interference issues.

Omnidirectional Antenna: This type of antenna broadcasts signals in all directions but does not mitigate interference.

Captive Portal: A web page that users must view and interact with before accessing a network, unrelated to frequency interference.

Ad Hoc Network: A decentralized wireless network that does not address interference issues directly.

Implementation:

Switch Wi-Fi devices to the 5GHz band if supported by the network infrastructure and client devices.

Configure Wi-Fi access points to use non-overlapping channels within the 2.4GHz band to minimize interference.

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.

When a network interface's indicator lights are not blinking on either the computer or the switch, it suggests a physical layer issue. Here is the detailed reasoning:

Ethernet Properly Connected: The Ethernet cable is correctly connected, eliminating issues related to a loose or faulty cable.

No Indicator Lights: The absence of blinking indicator lights on both the computer and the switch typically points to the port being administratively shut down.

Switch Port Shut Down: In networking, a switch port can be administratively shut down, disabling it from passing any traffic. This state is configured by network administrators and can be verified and changed using the command-line interface (CLI) of the switch.

Command to Check and Enable Port:

bash

Copy code

Switch> enable

Switch# configure terminal

Switch(config)# interface [interface id]

Switch(config-if)# no shutdown

The command no shutdown re-enables the interface if it was previously disabled. This will restore the link and the indicator lights should start blinking, showing activity.

Basic Configuration Commands PDF, sections on interface configuration (e.g., shutdown, no shutdown)​​.

The customer can access local resources (a database server), which means local networking is working. However, the inability to reach the internet suggests an issue with the default gateway. If the default gateway is unreachable, packets will not be routed outside the local network.

Breakdown of Options:

A. Incorrect DNS – DNS issues would cause problems resolving domain names, but the user should still be able to access external resources via IP addresses.

B. Unreachable gateway – ✅ Correct answer. If the default gateway is incorrect or unreachable, the device cannot route traffic to the internet.

C. Failed root bridge – STP (Spanning Tree Protocol) failures cause switching issues, but the user can still access local devices, meaning STP is not the problem.

D. Poor upstream routing – Would affect the entire network, not just one user.

To support VoIP on a network with limited switchports, the engineer should configure voice VLANs and enable 802.1Q tagging. Voice VLANs allow VoIP traffic to be prioritized and isolated from data traffic even when sharing the same physical port. 802.1Q is used for VLAN tagging, enabling multiple VLANs over a single physical link.

From Andrew Ramdayal’s guide:

“Voice VLANs allow IP phones and computers to share the same physical switch port while keeping their traffic separate. 802.1Q is used to tag VLAN traffic so that it can be appropriately routed and prioritized.”

An SVI (Switched Virtual Interface) is a logical interface on a Layer 3-capable switch used to route traffic between VLANs. This is particularly useful in environments where voice and data traffic need to be separated, as each type of traffic can be assigned to different VLANs and routed accordingly.

SVI (Switched Virtual Interface): A virtual interface created on a switch for inter-VLAN routing.

VLAN Routing: Enables the routing of traffic between VLANs on a Layer 3 switch, allowing for logical separation of different types of traffic, such as voice and data.

Use Case: Commonly used in scenarios where efficient and segmented traffic management is required, such as in VoIP implementations.

Network References:

CompTIA Network+ N10-007 Official Certification Guide: Discusses VLANs, SVIs, and their applications in network segmentation and routing.

Cisco Networking Academy: Provides training on VLAN configuration and inter-VLAN routing using SVIs.

Network+ Certification All-in-One Exam Guide: Covers network segmentation techniques, including the use of SVIs for VLAN routing.

DNS filtering blocks access to known malicious websites by comparing domain requests against a list of allowed or blocked URLs. It is an effective defense against phishing and other web-based attacks.

From Andrew Ramdayal’s guide:

“URL filtering restricts access to specific websites or web content by comparing URLs against a predefined list of allowed or blocked sites…commonly used to prevent users from accessing malicious sites.”

Understanding the Requirements

Network Address: 192.168.1.0/24

The /24 notation means a subnet mask of 255.255.255.0, providing 256 total addresses (192.168.1.0–192.168.1.255).

Usable hosts: 256 – 2 (network and broadcast) = 254.

Goal: Create 3 subnets, each with 30 hosts.

Each subnet needs enough addresses to accommodate 30 hosts, plus 2 reserved addresses (network and broadcast) per subnet.

Total addresses per subnet = 30 (hosts) + 2 (network/broadcast) = 32 addresses.

Subnetting Basics (Networking Fundamentals)

Subnet Mask: Determines how many bits are borrowed from the host portion to create subnets.

Original Mask: /24 (255.255.255.0) = 24 network bits, 8 host bits.

Formulae:

Number of subnets = 2^(number of borrowed bits).

Number of addresses per subnet = 2^(remaining host bits).

Usable hosts per subnet = 2^(remaining host bits) – 2.

We need:

At least 3 subnets.

At least 32 addresses per subnet (to fit 30 hosts + 2 reserved).

Step-by-Step Analysis

Determine Addresses Needed per Subnet:

32 addresses is a power of 2 (2^5 = 32).

This means each subnet requires 5 host bits (since 2^5 = 32 total addresses, and 32 – 2 = 30 usable hosts).

Calculate Remaining Bits:

Original network has 8 host bits (/24).

If 5 bits are left for hosts, we borrow: 8 – 5 = 3 bits for subnetting.

New Subnet Mask:

Original mask: /24 (24 network bits).

Borrow 3 bits: 24 + 3 = /27.

/27 = 255.255.255.224 (binary: 11111111.11111111.11111111.11100000).

Verify Requirements:

Number of Subnets: 2^3 = 8 subnets (meets the requirement of at least 3).

Addresses per Subnet: 2^5 = 32 addresses.

Usable Hosts per Subnet: 32 – 2 = 30 hosts (exactly meets the requirement).

Subnet Breakdown:

Increment: 256 – 224 = 32 (each subnet increments by 32 in the fourth octet).

Subnets:

192.168.1.0–192.168.1.31 (Network: .0, Broadcast: .31, Hosts: .1–.30)

192.168.1.32–192.168.1.63 (Network: .32, Broadcast: .63, Hosts: .33–.62)

192.168.1.64–192.168.1.95 (Network: .64, Broadcast: .95, Hosts: .65–.94)

(And 5 more subnets up to 192.168.1.255.)

Three subnets fit perfectly with 30 hosts each.

Evaluating the Options

A. 255.255.255.128 (/25):

Borrow 1 bit: 24 + 1 = /25.

Subnets: 2^1 = 2 (not enough, need 3).

Host bits: 7 (2^7 = 128 addresses, 126 hosts).

Why Not: Only 2 subnets, fails the requirement.

B. 255.255.255.192 (/26):

Borrow 2 bits: 24 + 2 = /26.

Subnets: 2^2 = 4 (meets 3).

Host bits: 6 (2^6 = 64 addresses, 62 hosts).

Why Not: 62 hosts exceeds 30, but it’s overkill; /27 is more efficient and still valid.

C. 255.255.255.224 (/27):

Borrow 3 bits: 24 + 3 = /27.

Subnets: 2^3 = 8 (meets 3).

Host bits: 5 (2^5 = 32 addresses, 30 hosts).

Why Yes: Perfectly fits 3 subnets with exactly 30 hosts each.

D. 255.255.255.240 (/28):

Borrow 4 bits: 24 + 4 = /28.

Subnets: 2^4 = 16 (meets 3).

Host bits: 4 (2^4 = 16 addresses, 14 hosts).

Why Not: Only 14 hosts per subnet, fails the 30-host requirement.

Why /27 (255.255.255.224) is Best

It provides exactly 30 usable hosts per subnet, avoiding waste while meeting the minimum requirement.

It allows 8 subnets, exceeding the need for 3, ensuring flexibility.

The study guide emphasizes efficient subnet design, and /27 balances host count and subnet availability.

CompTIA Network+ Context

Networking Fundamentals: Subnetting is a core skill, requiring understanding of CIDR, binary conversion, and address allocation.

Example from Study Guide: Similar problems calculate subnet masks for specific host counts, reinforcing /27 as a common solution for ~30 hosts.

SFTP (Secure File Transfer Protocol) operates over port 22, using SSH (Secure Shell) encryption for secure file transfers.

Breakdown of Options:

A. 22 – Correct answer. SFTP runs over SSH (port 22) for secure file transfers.

B. 80 – Used for HTTP, not SFTP.

C. 443 – Used for HTTPS (secure web traffic).

D. 3389 – Used for RDP (Remote Desktop Protocol).

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.

VLANs (Virtual Local Area Networks) segment network traffic by department, allowing ACLs (Access Control Lists) to be applied based on VLAN membership, improving security and resource isolation.

Breakdown of Options:

A. VLAN – Correct answer. VLANs enable logical network segmentation, allowing ACLs per department.

B. DHCP – Assigns IP addresses but does not control access.

C. VPN – Provides remote access, not segmentation within a network.

D. STP – Prevents switching loops, not related to ACL implementation.

A toner and probe tool, also known as a tone generator and probe, is used to trace and identify individual cables within a bundle or to locate the termination points of cables in wiring closets and patch panels. It generates a tone that can be picked up by the probe, helping technicians quickly and accurately identify and label wall plates and wiring. This is the best tool for identifying proper wiring in the Intermediate Distribution Frame (IDF). References: CompTIA Network+ Exam Objectives and official study guides.