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

Border Gateway Protocol (BGP): BGP is the most commonly used routing protocol for interconnecting WANs, especially across the internet. It is used for exchanging routing information between autonomous systems (AS), making it the backbone protocol for large-scale WANs.

IGP (A): Interior Gateway Protocols like OSPF and EIGRP are typically used within a single AS, not between them.

EIGRP (B): While it is efficient, EIGRP is primarily used for intra-domain routing and not ideal for WAN interconnection.

OSPF (D): While OSPF can be used for WANs, it is not as common as BGP for inter-AS communication.

In a data center that uses hot aisle/cold aisle ventilation, equipment is typically installed so that cool air enters from the cold aisle (front) and hot air is exhausted to the hot aisle (rear). This configuration maximizes cooling efficiency.

BYOD (Bring Your Own Device) policies define rules for using personal devices on the company network. Since the new employee is using a personal laptop, this policy applies.

Breakdown of Options:

A. IAM (Identity and Access Management) – Governs user permissions, not device policies.

B. BYOD (Bring Your Own Device) – ✅ Correct answer. Covers using personal devices for work.

C. DLP (Data Loss Prevention) – Focuses on preventing sensitive data leaks, not device usage policies.

D. AUP (Acceptable Use Policy) – Covers internet and system usage, but not personal device rules.

Elasticity is the ability of a system (often in cloud environments) to automatically scale resources up or down in real time based on demand.

A. Scalability means the ability to grow over time but not necessarily dynamically.

B. SaaS is a service model, not a resource-allocation concept.

C. Hybrid cloud is a deployment model, not a performance behavior.

References (CompTIA Network+ N10-009):

Domain: Networking Concepts — Cloud computing, elasticity vs. scalability.

Console Access:

Purpose: Console access to a switch allows administrators to configure and manage the device directly. This is typically done using a terminal emulator program on a computer.

RJ45 Connector:

Common Use: The RJ45 connector is widely used for Ethernet cables and also for console connections to network devices like switches and routers.

Console Cables: Console cables often have an RJ45 connector on one end (for the switch) and a DB9 serial connector on the other end (for the computer).

Comparison with Other Connectors:

ST (Straight Tip): A fiber optic connector used for networking, not for console access.

BNC (Bayonet Neill-Concelman): A connector used for coaxial cable, typically in older network setups and not for console access.

SFP (Small Form-factor Pluggable): A modular transceiver used for network interfaces, not for console access.

Practical Application:

Connection Process: Connect the RJ45 end of the console cable to the console port of the switch. Connect the DB9 end (or USB via adapter) to the computer. Use a terminal emulator (e.g., PuTTY, Tera Term) to access the switch’s command-line interface (CLI).

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.

VLAN hopping occurs when an attacker tricks a switch into believing the host is another switch by generating tagged frames or exploiting trunk negotiation (DTP). This allows the attacker to access traffic from multiple VLANs, potentially stealing sensitive data.

B. Evil twin is a rogue wireless AP attack, unrelated to switch impersonation.

C. DNS poisoning corrupts name resolution, not VLAN access.

D. ARP spoofing is a Layer 2 on-path attack, not masquerading as a switch.

References (CompTIA Network+ N10-009):

Domain: Network Security — VLAN hopping attacks, switch spoofing techniques.

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.

The most common protocol for secure VPNs is IPsec (Internet Protocol Security). IPsec provides confidentiality, integrity, and authentication for VPN traffic, typically using ESP (Encapsulating Security Payload). It is used in both site-to-site and remote access VPNs.

B. GRE encapsulates traffic but does not provide encryption.

C. BGP is a routing protocol, not a VPN technology.

D. SSH can be used for secure tunneling but is not the standard for VPN deployment.

IPsec is the industry standard because it operates at Layer 3, securing IP traffic regardless of the application, making it highly versatile.

References (CompTIA Network+ N10-009):

Domain: Network Security — VPN protocols, IPsec, ESP.

Definition of MAC Flooding:

MAC flooding is an attack where a malicious actor sends numerous fake MAC addresses to a switch, overwhelming its CAM table. The CAM table stores MAC addresses and their associated ports for efficient traffic forwarding.

Impact of MAC Flooding:

CAM Table Overflow: When the CAM table is full, the switch cannot learn new MAC addresses and is forced to broadcast traffic to all ports, leading to a degraded network performance and potential data interception.

Switch Behavior: The switch operates in a fail-open mode, treating the network as a hub, which can be exploited for eavesdropping on traffic.

Comparison with Other Attacks:

ARP Spoofing: Involves sending false ARP (Address Resolution Protocol) messages to associate the attacker's MAC address with the IP address of another device.

Evil Twin: Involves creating a rogue wireless access point that mimics a legitimate one to intercept data.

DNS Poisoning: Involves corrupting the DNS cache with false information to redirect traffic to malicious sites.

Preventive Measures:

Port Security: Configure port security on switches to limit the number of MAC addresses per port, preventing CAM table overflow.

Network Segmentation: Use VLANs to segment network traffic and limit the impact of such attacks.

A jump box is a hardened system that provides secure access to isolated or sensitive devices on a separate network.

Breakdown of Options:

A. Jump box – ✅ Correct answer. Acts as a middle point for secure remote access.

B. API gateway – Used for managing API calls, not remote access to isolated devices.

C. Secure Shell (SSH) – Requires direct connectivity, which may not be available for an isolated device.

D. Clientless VPN – Allows web-based VPN access, but does not guarantee access to isolated devices.

After implementing a solution and putting preventive measures in place, the next step is to verify that the system is functioning correctly. This ensures that the issue has been fully resolved.

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A split-tunnel VPN allows some traffic to be routed through the VPN while other traffic goes directly to the internet. This setup offers several advantages, with a primary one being cost-effectiveness due to cloud-based traffic not consuming company bandwidth.

Bandwidth Utilization: Split-tunnel VPNs reduce the amount of traffic passing through the company's network, freeing up bandwidth for other uses.

Performance: By allowing internet-bound traffic to bypass the VPN, it can reduce latency and improve the performance for users accessing cloud services directly.

Cost Savings: Reduced load on the company's VPN infrastructure can lead to lower costs in terms of both hardware and bandwidth.

Network References:

CompTIA Network+ N10-007 Official Certification Guide: Covers VPN types, including split-tunnel configurations and their advantages.

Cisco Networking Academy: Discusses VPN technologies and the benefits of split-tunneling.

Network+ Certification All-in-One Exam Guide: Provides detailed information on VPN setups, including the cost-effectiveness of split-tunnel VPNs.

By allowing cloud-based traffic to flow outside the company’s network, a split-tunnel VPN optimizes resource usage and enhances the overall network performance without incurring extra costs for bandwidth.

An IP Helper (IP Helper Address) allows DHCP requests to pass through routers and reach a DHCP server on another network.

DHCP broadcasts are not forwarded across routers by default, so an IP Helper Address is needed to relay the request.

This is crucial for large networks where a single DHCP server serves multiple subnets.

Option B (Reservation): Ensures a specific IP address is assigned to a MAC address but does not relay DHCP across networks.

Option C (Exclusion): Prevents specific IP addresses from being assigned, but does not help with DHCP relay.

Option D (Scope): Defines the range of IP addresses available for DHCP clients but does not assist in cross-network communication.

? Reference: CompTIA Network+ (N10-009) Official Study Guide – Section: DHCP and IP Addressing

The correct answer is public cloud. In public cloud models, a provider (such as AWS, Azure, or Google Cloud) hosts infrastructure and services that are shared across multiple customers, known as multitenancy. Each tenant is logically isolated, but physical infrastructure is shared, allowing providers to achieve economies of scale.

A. Private cloud is dedicated to one organization, not multitenant.

B. Community cloud is shared among organizations with common interests, but it’s less common than public multitenancy.

D. Hybrid cloud combines private and public but does not define tenancy alone.

Public cloud services are the most cost-effective and scalable because they spread costs across many customers, but they require strong security and isolation to protect tenants.

References (CompTIA Network+ N10-009):

Domain: Networking Concepts — Cloud models, multitenancy, public vs private.

Cross talk can often be caused by improper termination of cables. The first step in troubleshooting should be to inspect the connectors for any wires that might be touching or exposed. Ensuring that all wires are correctly seated and that no conductors are exposed can help reduce or eliminate cross talk. This step should be taken before attempting to re-terminate the connections or check for other sources of interference.References: CompTIA Network+ study materials.

The loopback address 127.0.0.1 is used to test the TCP/IP stack of the local machine. Pinging this address confirms whether the local system's networking stack is functioning correctly.

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Link aggregation(also known as port channeling or EtherChannel) allows multiple physical connections to act as one logical connection. This avoids loops that would typically be prevented by STP and provides redundancy and increased bandwidth. It's ideal when STP is not available or desirable.