CompTIA N10-009 - CompTIA Network+ Certification Exam

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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Servers shut down due to overheating, not loss of electrical power. Although UPS units had battery life, without cooling systems (HVAC/air conditioning) running on backup power, server rooms overheated. Backup power for air-conditioning is essential in data center design.

B. Door locks are unrelated to server shutdown.

C. Increasing UPS capacity won’t help cooling.

D. IoT thermostats may monitor temperature but won’t prevent overheating.

References (CompTIA Network+ N10-009):

Domain: Network Infrastructure — Environmental controls, power redundancy, HVAC systems.

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.”

Installing server equipment in a rack increases compute density by allowing multiple servers to be organized efficiently in a vertical configuration, saving space while housing more devices in a smaller footprint. This is critical for data centers and businesses with high hardware demands.

Simplified troubleshooting process (A): While racks can aid in organizing equipment, this is a secondary benefit, not the primary purpose.

Decreased power consumption (B): Rack installation does not directly reduce power usage; equipment power consumption remains the same.

Improved network performance (C): Racking servers does not inherently improve network performance; that depends on network configurations.

Multitenancy is a cloud computing architecture where a single instance of software serves multiple customers or tenants. Each tenant's data is isolated and remains invisible to other tenants. Hosting a company application in the cloud to be available for both internal and third-party users fits this concept, as it allows shared resources and infrastructure while maintaining data separation and security. References: CompTIA Network+ Exam Objectives and official study guides.

APIPA (Automatic Private IP Addressing) assigns an IP address in the range 169.254.x.x when a DHCP server cannot be contacted, and it sets the default gateway to 0.0.0.0 because APIPA is designed only for local communication within the same subnet. The document states:

“APIPA allows for automatic, ad hoc network communication within a single subnet when a DHCP server is not available. In this state, the default gateway is typically set to 0.0.0.0 because APIPA does not provide routing to other networks.”

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.

Enterprise authentication (such as WPA2-Enterprise) utilizes unique credentials for each user, typically integrating with an authentication server like RADIUS. This allows for tracking and logging user activity, ensuring that all connections can be traced back to individual users. PSKs (Pre-Shared Keys) are shared among users and do not provide individual accountability. Captive portals can identify users but are less secure than enterprise authentication, and Wired Equivalent Privacy (WEP) is outdated and not recommended for security purposes.

When traffic moves laterally between VMs within the same network or subnet, it is known as east-west traffic. This contrasts with north-south traffic, which refers to communication between internal and external networks.

Breakdown of Options:

A. East-west – Correct answer. This refers to traffic between internal servers or VMs, which is a common security concern.

B. Point-to-point – Point-to-point describes a direct connection between two devices, but does not specifically define lateral movement.

C. Horizontal-scaling – This refers to adding more instances or nodes in cloud computing, unrelated to traffic flow.

D. Hub-and-spoke – This network topology describes a centralized design, not lateral traffic.

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.