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

The right answer is C. BNC . A BNC connector is associated with coaxial cabling , which has been used for certain networking, video, and radio frequency applications. In networking history, coax with BNC connectors was common in older Ethernet implementations such as 10BASE2.

The other choices point to different media types. SC is a fiber optic connector. MPO is also a fiber connector, usually for high-density fiber connections. RJ11 is commonly used for telephone wiring rather than coaxial network cabling. Since the question specifically asks about transmission through a coaxial cable , BNC is the only match.

This is one of those basic media and connector recognition questions that CompTIA likes to include. The goal is to connect the connector type to the cabling standard it belongs with. When you see coax, the classic connector to remember is BNC . When you see fiber, think of connectors such as SC, LC, ST, or MPO. When you see telephone pairs, RJ11 is the common answer.

So the clean way to solve this one is by matching cable type to connector type. Coaxial cable goes with BNC .

The correct answer is /25, which is the appropriate subnet mask for dividing an existing Class C network into two equal subnets. According to the CompTIA Network+ N10-009 objectives, subnetting is a core networking concept used to improve network segmentation, performance, and security.

A Class C network uses a default subnet mask of /24 (255.255.255.0), which provides 256 total addresses (254 usable). To split this network into two sections, the administrator must borrow one host bit from the last octet. Borrowing one bit results in a /25 subnet mask (255.255.255.128). This creates two subnets, each with 128 total addresses (126 usable)—an ideal solution for separating two departments such as finance and marketing.

A /24 would not create any segmentation, as it represents the original single network. A /26 would create four subnets, and a /27 would create eight subnets, both of which exceed the requirement of only two sections and unnecessarily reduce the number of available host addresses per subnet.

The Network+ objectives emphasize selecting subnet masks based on organizational requirements, balancing the number of subnets with sufficient host capacity. In this scenario, /25 is the most efficient and correct choice.

A /21 subnet mask means 21 bits are network bits:

8 + 8 + 5 = 21 → leaves 11 bits for hosts.

Subnet mask in binary: 11111111.11111111.11111000.00000000

Converted to decimal: 255.255.248.0

Therefore:

A. /19 = 255.255.224.0

B. /20 = 255.255.240.0

✅ C. /21 = 255.255.248.0 ← correct

D. /22 = 255.255.252.0

Answer correction: The correct option is C. 255.255.248.0, not B.

References (CompTIA Network+ N10-009):

Domain: Networking Concepts — Subnetting, CIDR notation, dotted decimal masks.

This is an example of Multi-Factor Authentication (MFA) because it requires:

Something you know (username/password)

Something you have (a phone-generated passcode)

Breakdown of Options:

A. SSO (Single Sign-On) – Allows one login for multiple services, but does not add a second authentication factor.

B. LDAP (Lightweight Directory Access Protocol) – Used for directory authentication, not MFA.

C. MFA (Multi-Factor Authentication) – ✅ Correct answer. Uses multiple authentication factors for better security.

D. SAML (Security Assertion Markup Language) – Used for federated identity management, not multi-factor authentication.

Introduction to Security Zones:

Security zones are logical segments within a network designed to enforce security policies and control access. They help in segregating and securing different parts of the network.

Types of Security Zones:

Trusted Zone: This is the most secure zone, typically used for internal corporate networks where only trusted users have access.

Extranet: This zone allows controlled access to external partners, vendors, or customers.

VPN (Virtual Private Network): While VPNs are used to create secure connections over the internet, they are not a security zone themselves.

Public Zone: This zone is the least secure and is typically used for public-facing services accessible by anyone.

Trusted Zone Implementation:

The trusted zone is configured to include internal corporate users and resources. Access controls, firewalls, and other security measures ensure that only authorized personnel can access this zone.

Internal network segments, such as the finance department, HR, and other critical functions, are usually placed in the trusted zone.

Example Configuration:

Firewall Rules: Set up rules to allow traffic only from internal IP addresses.

Access Control Lists (ACLs): Implement ACLs on routers and switches to restrict access based on IP addresses and other criteria.

Segmentation: Use VLANs and subnetting to segment and isolate the trusted zone from other zones.

Explanation of the Options:

A. Extranet: Suitable for external partners, not for internal-only access.

B. Trusted: The correct answer, as it provides controlled access to internal corporate users.

C. VPN: A method for secure remote access, not a security zone itself.

D. Public: Suitable for public access, not for internal corporate users.

Conclusion:

Implementing a trusted zone is the best solution for controlling access within a corporate network. It ensures that only trusted internal users can access sensitive resources, enhancing network security.

Once the theory has been tested and confirmed, the next step is to implement the solution based on the CompTIA troubleshooting model.

CompTIA Troubleshooting Model:

Identify the problem.

Establish a theory of probable cause.

Test the theory.

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

Verify full system functionality.

Document findings, actions, and outcomes.

Breakdown of Options:

A. Develop a theory – The theory has already been developed and tested.

B. Establish a plan of action – This happens before implementation, but since the issue is confirmed, it ' s time to act.

C. Implement the solution – Correct answer. The problem is confirmed, so the fix should be applied.

D. Document the findings – Documentation is the final step, not the next one.

The key difference is that an Intrusion Prevention System (IPS) is installed in line with network traffic, allowing it to actively block threats. In contrast, an Intrusion Detection System (IDS) only monitors and alerts without actively blocking traffic.

Breakdown of Options:

A. An IPS needs to be installed in line with traffic and an IDS does not. ✅ Correct answer. IPS actively prevents threats, while IDS only detects them.

B. An IPS is signature-based and an IDS is not. – False, both can use signature-based detection.

C. An IPS is less susceptible to false positives than an IDS. – False, both can produce false positives, depending on configurations.

D. An IPS requires less administrative overhead than an IDS. – False, IPS requires more administrative effort due to real-time blocking decisions.

Routers determine the best route to a destination using longest prefix match. This means the router chooses the route entry with the most specific matching network prefix for the destination IP address. For example, if a routing table contains 10.1.0.0/16 and 10.1.2.0/24, a packet destined to 10.1.2.50 matches both entries, but the router prefers /24 because it is more specific (longer mask). Network+ (N10-009) routing fundamentals emphasize that route selection begins with prefix length specificity before considering other factors within the same prefix length (such as administrative distance and metric, depending on the platform).

“Shortest prefix match” is the opposite of correct behavior. “Routes learned from EIGRP” and “routes learned from OSPF” describe sources of routes, not the general selection rule routers use when multiple matching routes exist. Even if routes come from different protocols, the router still applies selection logic; the universal rule for matching destination networks is longest prefix match. Hence, option C is correct.

MIB (Management Information Base): A MIB is a database used for managing the entities in a communication network. The MIB is used by Simple Network Management Protocol (SNMP) to translate events into a readable format, enabling network administrators to manage and monitor network devices effectively.

Function of MIB: MIBs contain definitions and information about all objects that can be managed on a network using SNMP. These objects are defined using a hierarchical namespace containing object identifiers (OIDs).

CompTIA Network+ materials discussing SNMP and MIB functionality​​.

Port 443 is used by HTTPS (Hypertext Transfer Protocol Secure), a secure version of HTTP that uses SSL/TLS to encrypt the communication between a client and server. This ensures confidentiality and integrity of data in transit. The document states:

“Port 443 is the default port for HTTPS, which secures HTTP traffic using SSL/TLS, providing encryption and secure identification of web servers.”

•The issue described is a network bottleneck due to increased traffic after a merger.

•A collapsed core architecture consolidates the core and distribution layers into a single layer to improve efficiency and reduce latency.

•Until the 40GB switch is acquired, Link Aggregation (LAG) (IEEE 802.3ad / LACP) can be used to combine multiple physical links into a single logical link, increasing bandwidth and reducing bottlenecks.

•FHRP (First Hop Redundancy Protocol) (A) is used for gateway redundancy, not link aggregation.

•Route selection metric changes (B) help with routing decisions but don’t address physical link congestion.

•Load balancers (C) distribute traffic for applications, not network links.

???? Reference: CompTIA Network+ N10-009 Official Documentation – Network Architecture and Performance Optimization.

SIEM (Security Information and Event Management) systems are used to aggregate and analyze log data from various sources, including firewalls, to detect potential security incidents and assist in regulatory compliance. The document explains:

“SIEM solutions aggregate and analyze log and event data from multiple devices, including firewalls, across different locations. They help in real-time monitoring, incident response, and ensuring compliance with security policies.”

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.

The correct answer is Integrity because a hashing algorithm ensures that data has not been altered. According to CompTIA Network+ (N10-009) security objectives, hashing is a cryptographic process that takes input data of any size and produces a fixed-length output known as a hash value or digest. If even a single bit of the original data changes, the resulting hash value will be significantly different.

Hashing is commonly used to verify file integrity, validate message authenticity, and securely store passwords. For example, when downloading software, the vendor may publish a hash value so users can calculate the hash of the downloaded file and confirm it matches, ensuring the file was not tampered with.

Non-repudiation (Option A) typically requires digital signatures that combine hashing with asymmetric encryption to verify the sender’s identity. Confidentiality (Option C) is achieved through encryption, which protects data from unauthorized access. Availability (Option D) refers to ensuring systems and data are accessible when needed and is not related to hashing functions.

Therefore, hashing primarily provides data integrity verification.