CompTIA N10-009 Exam Dumps & Practice Test Questions

Question 1:

What is the main function of a subnet mask in an IP network?

A. To divide a network into smaller subnetworks
B. To encrypt data being transmitted over a network
C. To identify the type of device connected to the network
D. To translate domain names into IP addresses

Correct Answer: A

Explanation:

A subnet mask plays a fundamental role in IP networking by defining how an IP address is divided into its network and host portions. The primary purpose of a subnet mask is to segment a larger IP network into smaller, more manageable subnetworks or subnets. This segmentation helps network administrators efficiently allocate IP address space, improve routing performance, and enhance security within a network.

Subnetting is essential in large-scale environments such as corporate networks, where thousands of devices may be present. Instead of placing all devices within a single large broadcast domain, subnetting breaks the network into logical segments. This reduces the size of each broadcast domain, lowering the amount of broadcast traffic and thus improving overall network performance.

Technically, a subnet mask is a 32-bit binary pattern that, when applied to an IP address, distinguishes the network ID from the host ID. For example, a subnet mask of 255.255.255.0 (or /24 in CIDR notation) indicates that the first 24 bits of an IP address represent the network, and the remaining 8 bits can be used for host addresses within that subnet. This means you can have up to 254 usable host addresses in that subnet.

Let’s break down the incorrect options:

• B is incorrect because encryption is handled by security protocols such as SSL/TLS, IPsec, or HTTPS—not the subnet mask.

• C is incorrect since identifying the type of device on a network involves MAC addresses, ARP tables, or device management tools, not subnet masks.

• D is incorrect because translating domain names into IP addresses is the job of DNS (Domain Name System), not the subnet mask.

Therefore, A is the correct answer. Subnet masks are crucial for network planning and control, enabling administrators to structure networks logically and efficiently.

Question 2:

Which protocol ensures secure communication when accessing websites over the Internet?

A. HTTP
B. FTP
C. HTTPS
D. SMTP

Correct Answer: C

Explanation:

The protocol responsible for secure web browsing is HTTPS, which stands for Hypertext Transfer Protocol Secure. It is the secure version of HTTP and is widely used to protect data transferred between a user’s browser and a website’s server.

HTTPS works by incorporating encryption protocols, specifically SSL (Secure Sockets Layer) or its more modern successor TLS (Transport Layer Security). These protocols encrypt the data exchanged so that even if a third party intercepts the data, it remains unintelligible without the proper decryption keys. This protects sensitive information such as login credentials, credit card numbers, and personal data from being compromised.

When a user visits an HTTPS-enabled website, the browser and the server initiate a process known as the TLS handshake, which establishes a secure session. During this handshake, the server provides a digital certificate (often issued by a trusted Certificate Authority) that authenticates its identity. Once trust is established and encryption keys are exchanged, secure communication begins.

Let’s examine the incorrect options:

• A (HTTP) is the non-secure counterpart to HTTPS. Data sent over HTTP is in plaintext, meaning it can be intercepted and read by anyone with access to the network traffic.

• B (FTP) stands for File Transfer Protocol, which is used to transfer files over a network. While useful for file sharing, it does not provide encryption unless specifically configured with FTPS or SFTP.

• D (SMTP) stands for Simple Mail Transfer Protocol and is used for sending email—not for browsing websites. Like FTP, it can be configured with security extensions but is unrelated to secure web traffic.

In conclusion, C is the correct answer because HTTPS is the standard for secure website communication, safeguarding user data through encryption and authentication mechanisms that ensure confidentiality and integrity.

Question 3:

Which layer of the OSI model is responsible for establishing, managing, and terminating connections?

A) Application layer
B) Transport layer
C) Network layer
D) Session layer

Correct answer: D

Explanation:

The Session layer (Layer 5) of the OSI model is responsible for establishing, managing, and terminating sessions between applications on communicating devices. It controls dialogues (sessions) between computers by coordinating communication and ensuring sessions are maintained properly, including synchronization, checkpointing, and recovery.

Unlike the Application layer (Layer 7), which is more user-facing and focuses on enabling services like HTTP or FTP, or the Transport layer (Layer 4), which manages data flow control, segmentation, and error recovery, the Session layer ensures that sessions are properly coordinated. It establishes logical connections for communication and manages how long a session should persist, and when and how it should be closed or reestablished after interruptions.

The Network layer (Layer 3) is primarily involved in routing data across networks using IP addressing and does not deal with session state or management.

Therefore, when the primary concern is the control of logical dialogues between systems—including starting, maintaining, and closing those sessions—the Session layer is the correct and relevant OSI layer.

Question 4:

Which of the following devices operates at the data link layer of the OSI model?

A) Router
B) Switch
C) Hub
D) Modem

Correct answer: B

Explanation:

The Switch operates at the Data Link layer (Layer 2) of the OSI model. Its primary function is to use MAC addresses to forward frames to the correct destination device within the same local area network (LAN). This selective forwarding enhances efficiency and reduces unnecessary broadcast traffic compared to a hub.

Switches intelligently maintain a MAC address table, which allows them to make forwarding decisions per frame. This capability enables better network performance, supports full-duplex communication, and enables the implementation of advanced features like VLANs, traffic segmentation, and sometimes Layer 3 routing if the switch supports it.

Let’s compare with the other devices:

• A) Router: Operates at Layer 3 (Network layer). It uses IP addresses for routing packets between different networks.

• C) Hub: Operates at Layer 1 (Physical layer). It blindly broadcasts all incoming signals to every port, leading to network inefficiencies.

• D) Modem: Functions primarily at Layer 1, and sometimes Layer 2, depending on whether it handles framing and error detection. It modulates and demodulates signals between digital and analog forms.

Thus, only the Switch consistently operates at the Data Link layer, making B the correct answer.

Question 5:

Which networking device is responsible for operating at the second layer (Data Link layer) of the OSI model and uses MAC addresses to forward data within a local network?

A) Router
B) Switch
C) Hub
D) Modem

Correct answer: B

Explanation:

The switch is a device that operates at the Data Link layer (Layer 2) of the OSI model. Its main function is to manage traffic within a Local Area Network (LAN) by using MAC addresses to determine how to forward data frames to their correct destinations. Each port on a switch has a MAC address table, allowing it to intelligently direct data only to the port associated with the intended recipient device, rather than broadcasting to all devices like a hub would.

This capability improves network efficiency, reduces congestion, and minimizes collisions on the network. Switches also support features like VLANs (Virtual Local Area Networks), which can segment network traffic and isolate broadcast domains for added performance and security.

Here’s why the other options are incorrect:

• A) Router – Routers operate at Layer 3 (Network layer) and forward packets based on IP addresses, not MAC addresses. Their role is to route traffic between different networks or subnets.

• C) Hub – A hub operates at Layer 1 (Physical layer). It is a very basic networking device that simply repeats incoming signals to all connected ports, regardless of the destination. Hubs do not understand MAC addresses or perform any traffic management.

• D) Modem – A modem primarily functions at Layer 1, converting digital signals to analog for transmission over telephone or cable lines and vice versa. In some configurations, it can interact with Layer 2, but it is not responsible for MAC-based switching or traffic segmentation.

Therefore, the correct answer is B, as a switch operates at the Data Link layer and uses MAC addresses to forward data within a LAN.

Question 6:

Among the following wireless encryption standards, which one provides the strongest and most secure protection for Wi-Fi networks?

A) WEP
B) WPA
C) WPA2
D) TKIP

Correct answer: C

Explanation:

WPA2 (Wi-Fi Protected Access 2) is the most secure and widely recommended wireless encryption standard available for Wi-Fi networks. It uses the Advanced Encryption Standard (AES) for encryption, which is considered extremely strong and secure. AES is a symmetric encryption algorithm that has been adopted globally by governments, financial institutions, and security organizations for its resistance to brute-force and cryptographic attacks.

WPA2 was introduced as the successor to WPA (Wi-Fi Protected Access), which in turn was an improvement over WEP (Wired Equivalent Privacy). WPA originally used TKIP (Temporal Key Integrity Protocol) for encryption, which was a stopgap solution to WEP’s known flaws. While TKIP was more secure than WEP, it still had vulnerabilities and is no longer considered secure by modern standards.

Let’s look at the other options:

• A) WEP – This is the oldest and least secure encryption method. It uses the RC4 encryption algorithm with weak key management and is vulnerable to multiple known attacks. It can be cracked within minutes with commonly available tools.

• B) WPA – While better than WEP, WPA with TKIP still has significant security limitations. It was intended as a temporary fix and has since been superseded by WPA2.

• D) TKIP – TKIP is not a standalone encryption standard but part of WPA. It is weaker than AES and no longer considered secure due to vulnerabilities that allow attackers to compromise encrypted data.

In modern network environments, WPA2 with AES encryption is the minimum recommended standard for securing wireless networks. For even greater protection, WPA3, which improves upon WPA2, is now being rolled out. However, as of today, WPA2 remains the most secure widely supported option.

Thus, the correct answer is C, WPA2.

Question 7:

Which protocol is used to automatically assign IP addresses to devices on a network?

A. DNS
B. DHCP
C. FTP
D. SNMP

Correct Answer: B

Explanation:

DHCP (Dynamic Host Configuration Protocol) is a network management protocol used to automatically assign IP addresses and other network configuration settings to devices on a network. When a device joins a network, it broadcasts a DHCP Discover message. A DHCP server on the network replies with an available IP address and additional configuration details, such as the subnet mask, default gateway, and DNS servers.

This automatic process eliminates the need for manual IP address configuration, reducing administrative workload and minimizing configuration errors like duplicate IP assignments. DHCP also supports lease-based address allocation, meaning IPs can be reassigned after expiration, which improves IP address usage efficiency in dynamic environments like office networks, schools, or public Wi-Fi.

Let’s break down the incorrect options:

• A (DNS): The Domain Name System resolves human-friendly domain names into IP addresses. It doesn’t assign IPs to devices—it helps devices find the IP addresses of servers and services (e.g., turning example.com into 192.0.2.1).

• C (FTP): The File Transfer Protocol is used for transferring files between systems over a network. It has no role in IP address assignment.

• D (SNMP): The Simple Network Management Protocol is used for monitoring, managing, and gathering information from network devices like routers and switches. It is used for performance monitoring and fault management, not for assigning IP addresses.

Thus, DHCP is the correct answer, as it automates IP address allocation and is a foundational protocol in virtually every IP-based network.

Question 8:

Which of the following is a characteristic of a VPN?

A. It allows users to access a network over a secure, encrypted connection
B. It provides a direct physical connection between remote offices
C. It requires all traffic to be unencrypted for efficiency
D. It relies on an Internet Service Provider's backbone for connectivity

Correct Answer: A

Explanation:

A VPN (Virtual Private Network) provides a way for users to securely access a private network—like a corporate intranet—over a public network such as the internet. It does this by creating a tunnel that uses encryption to protect the data being transmitted. VPNs are essential for maintaining privacy, confidentiality, and data integrity, especially when users are working remotely or accessing sensitive company data from untrusted networks.

VPNs typically employ encryption protocols such as IPsec, SSL/TLS, or WireGuard, which ensure that even if the data is intercepted, it cannot be read or altered. This makes VPNs invaluable tools for remote workers, mobile employees, or anyone who needs to establish a secure connection over the internet.

Reviewing the incorrect options:

• B (Direct physical connection): VPNs are virtual solutions, not physical ones. While direct physical lines like leased lines offer private communication, VPNs achieve similar secure communication without dedicated physical links.

• C (Unencrypted traffic): This is false. VPNs are specifically used because they encrypt traffic. Encryption is central to their design, ensuring confidentiality and security.

• D (ISP backbone reliance): While VPN traffic may traverse an ISP’s infrastructure, that’s not a unique characteristic. All internet traffic does. What defines a VPN is how it secures the data, not the infrastructure it uses.

In summary, Option A correctly highlights the essential feature of a VPN: secure, encrypted access to a network over the internet.

Question 9:

What is the main role of a subnet mask in networking?

A) To design and establish the overall network layout
B) To break a large network into multiple smaller subnetworks
C) To direct traffic across various networks
D) To translate website names into IP addresses

Correct Answer: B

Explanation:

A subnet mask plays a vital role in IP networking by dividing a larger network into smaller, manageable segments known as subnets. This process, called subnetting, allows network administrators to optimize the allocation of IP addresses and enhance network efficiency, performance, and security. The subnet mask achieves this by distinguishing which portion of an IP address belongs to the network and which part identifies individual hosts within that network.

For example, consider the subnet mask 255.255.255.0. The “255” values indicate the bits reserved for the network portion, while the “0” denotes bits that can be used for host addresses. In this case, 8 bits are left for host assignment, meaning up to 254 devices (2⁸ - 2, excluding network and broadcast addresses) can exist within that subnet. This segmentation limits broadcast traffic to the local subnet and prevents unnecessary congestion across the entire network.

Subnetting also enhances security by isolating groups of devices. For instance, administrative systems can be placed on one subnet, while public-facing systems are placed on another. This separation reduces the risk of internal threats spreading across the network and enables more fine-grained control over access policies.

Let’s evaluate the incorrect options:

• A) While subnet masks help define how an IP address is interpreted within a network, they do not design or create the network's physical or logical architecture.

• C) Routing is performed by routers and other Layer 3 devices, which use the network portion of IP addresses (defined by subnet masks) to determine the best path for data. However, subnet masks themselves do not route traffic.

• D) The Domain Name System (DNS) is responsible for converting human-friendly domain names (e.g., example.com) into IP addresses. This process is unrelated to subnetting.

In conclusion, the subnet mask's primary function is to divide a single large network into smaller subnetworks, improving traffic flow, optimizing address allocation, and strengthening security. This makes B the correct answer.

Question 10:

Which protocol is specifically designed to enable secure data transmission over the internet?

A) HTTP
B) FTP
C) HTTPS
D) SMTP

Correct Answer: C

Explanation:

HTTPS (Hypertext Transfer Protocol Secure) is the secure version of HTTP and is used for protected communication over the internet. It ensures that the data transmitted between a user’s web browser and a website’s server is encrypted and secure from interception or tampering. This is achieved by using either SSL (Secure Sockets Layer) or, more commonly today, TLS (Transport Layer Security) protocols.

When you access a website using HTTPS, the browser initiates a handshake process with the server to establish an encrypted connection. Once completed, all communication—including logins, payments, and personal data—is securely transferred. This safeguards users from man-in-the-middle (MITM) attacks, where an attacker could intercept and alter traffic between the browser and the server.

Websites that use HTTPS are typically marked with a padlock icon in the browser’s address bar and have URLs beginning with https://. This visual cue signals to users that their interaction with the website is protected by encryption.

Let’s break down the other options:

• A) HTTP (Hypertext Transfer Protocol) is the basic protocol for loading web pages. However, it does not encrypt data, making it vulnerable to eavesdropping and interception.

• B) FTP (File Transfer Protocol) is used for transferring files over a network. Although secure variants like FTPS and SFTP exist, standard FTP lacks encryption and is not used for secure web browsing.

• D) SMTP (Simple Mail Transfer Protocol) is designed for sending emails, not web communication. While secure extensions like SMTPS exist, SMTP is not related to securing web traffic.

In today’s digital landscape, where cybersecurity threats are rampant, HTTPS is the standard for any website that handles user information. It ensures confidentiality, integrity, and authenticity during data exchange. Consequently, the correct choice is C, as HTTPS is the protocol that secures web communication through encryption.