CompTIA Network+ 2026 Prep practice questions and answers. Tap an option to test yourself — you'll see the correct answer and a plain-English explanation for every question. Free, no login.
Q21A small company is using a Linux-based server for authentication, but one of the users cannot log in due to authentication failures. What could be the most likely cause?
✓ Correct answer: D. Misconfigured time settings
Answer: Misconfigured time settings Authentication services often require system clocks to be closely synchronized for security tokens to be validated. A time discrepancy could prevent a user from logging in even if other network services appear to function normally. Incorrect permissions would prevent access to specific resources but would not necessarily block the user from logging in. An expired user account would typically give a clear message about account status. A duplicate hostname might cause network conflicts but would usually not prevent a user from authenticating.
Q22Which of the following is NOT a common practice for ensuring network security in an enterprise environment?
✓ Correct answer: C. Regular physical equipment replacement
Answer: Regular physical equipment replacement Securing a network typically involves practices like implementing firewall rules, enforcing strong password policies, and conducting regular security audits. Regular physical equipment replacement is not a standard security practice but rather a maintenance activity for hardware lifecycle management.
Q23Your organization is planning to enhance its disaster recovery plan by focusing on system availability. Which of the following metrics is MOST relevant for this?
✓ Correct answer: D. MTBF
Answer: MTBF Mean time between failures (MTBF) measures the average amount of time between failures of a particular component. This is relevant to system availability because it helps in understanding how frequently components are likely to fail, thus aiding in planning for redundancy and maintenance. The recovery point objective (RPO) measures how far back you have to go to fully recover from an outage. The recovery time objective (RTO) defines how long a component can be down without causing unacceptable consequences. Mean time to repair (MTTR) is the average amount of time between a component failing and the system being restored to normal operation; this should be minimized.
Q24When configuring a redundant power supply for a critical server, which option provides the most immediate failover but is the costliest?
✓ Correct answer: B. Online UPS
Answer: Online UPS Different types of UPS (Uninterruptible Power Supply) solutions offer varying levels of protection and failover capabilities: Standby UPS: The least expensive type, which only switches to battery power when mains supply fails, causing a brief interruption. Line-Interactive UPS: Offers better regulation against power fluctuations by using an autotransformer, but still has a brief switch-over time. Online UPS: Provides continuous power from its battery, eliminating switchover time entirely. This is the costliest option but offers the most immediate failover capability. Generator Backup: Provides long-term power but has the longest delay before becoming operational.
Q25Which of the following stages in the disaster recovery process involves restoring critical business functions and verifying the integrity of restored data?
✓ Correct answer: C. Recovery
Answer: Recovery Typical disaster recovery plans include the following stages: Stage Description Preparation **Prepare**: Organizations ensure that they have the resources and plans to handle a potential disaster. Detection **Detect**: Identification of a disaster event. Containment **Contain**: Steps to prevent the disaster from escalating. Mitigation **Mitigate**: Reducing the impact of the disaster through initial response actions. Recovery **Recovery**: Restoring affected systems and data to normal operations, including verification of data integrity. Review **Review**: Analyzing the response to improve future disaster recovery processes.
Q26In the context of wireless networks, which Wi-Fi security protocol observes and monitors for potential threats without allowing client access to the network?
✓ Correct answer: A. WIDS (Wireless Intrusion Detection System)
Answer: WIDS (Wireless Intrusion Detection System) WIDS monitors a wireless network for malicious activity or policy violations but does not allow client access. It observes network traffic and detects potential security issues. WEP is an outdated security protocol that provides minimal protection. WPA2 and WPA3 are current security protocols that offer strong protection by allowing client access while securing the network.
Q27In a wireless network, the frequency bands used for Wi-Fi communication are measured in which units?
✓ Correct answer: B. Gigahertz
Answer: Gigahertz. The frequency bands used in Wi-Fi communication are measured in gigahertz (GHz). Most common Wi-Fi standards use either 2.4 GHz or 5 GHz bands.
Q28Which protocol operates on Data Link Layer to automatically configure the switches in a local network?
✓ Correct answer: C. Spanning Tree Protocol
Answer: Spanning Tree Protocol The Spanning Tree Protocol (STP) is used at the Data Link Layer to prevent network loops and ensure efficient and reliable network communications by allowing switches to dynamically learn the network topology. The Address Resolution Protocol (ARP) is used in IPv4 networks to map IP addresses to MAC addresses. The Dynamic Host Configuration Protocol (DHCP) is used to automatically assign IP addresses to hosts. The Border Gateway Protocol (BGP) is used to exchange routing information between autonomous systems on the internet.
Q29In the context of wireless networking, which of the following devices always operates in multiple collision domains but a single broadcast domain?
✓ Correct answer: C. Wireless Access Point (WAP)
Answer: Wireless Access Point (WAP). WAPs create multiple collision domains, as each connected device communicates with the WAP independently. However, the WAP itself maintains a single broadcast domain for all connected devices. Repeaters operate within a single collision and broadcast domain because they simply amplify signals. Hubs also have a single collision and broadcast domain. Routers have multiple collision domains and can belong to multiple broadcast domains.
Q30Which of the following Wi-Fi technologies allows simultaneous dual-band operation, enabling devices to use 2.4 GHz and 5 GHz frequencies concurrently?
✓ Correct answer: A. 802.11ac
Answer: 802.11ac The 802.11ac Wi-Fi technology allows for simultaneous dual-band operation, which means devices can use both the 2.4 GHz and 5 GHz frequencies concurrently. This provides higher bandwidth and better performance. 802.11b only operates in the 2.4 GHz band and offers slower speeds. 802.11g also operates in the 2.4 GHz band but offers improved speeds compared to 802.11b. 802.11a operates in the 5 GHz band but does not support dual-band operation.
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Theory