Practice Free N10-009 Exam Online Questions
A network administrator is configuring access points for installation in a dense environment where coverage is often overlapping.
Which of the following channel widths should the administrator choose to help minimize interference in the 2.4GHz spectrum?
- A . 11MHz
- B . 20MHz
- C . 40MHz
- D . 80MHz
- E . 160MHz
B
Explanation:
Reference: CompTIA Network+ Certification Exam Objectives – Wireless Networks section.
A technician is troubleshooting wireless connectivity near a break room. Whenever a user turns on the microwave, connectivity to the user’s laptop is lost.
Which of the following frequency bands is the laptop most likely using?
- A . 2.4GHz
- B . 5GHz
- C . 6GHz
- D . 900MHz
A
Explanation:
The laptop is most likely using the 2.4GHz frequency band. According to the CompTIA Network+ N10-009 objectives, the 2.4GHz band is particularly susceptible to electromagnetic interference (EMI) from common household and office devices, including microwave ovens, cordless phones, Bluetooth devices, and baby monitors. Microwave ovens operate at approximately 2.45GHz, which overlaps directly with the 2.4GHz Wi-Fi spectrum. When the microwave is powered on, it emits interference that can significantly degrade or completely disrupt nearby wireless communications operating in this band.
The 5GHz and 6GHz bands operate at much higher frequencies and do not overlap with microwave emissions, making them far less prone to this type of interference. While higher-frequency bands have shorter range and lower wall penetration, they provide cleaner channels and improved performance in dense environments. The 900MHz band is not used by standard Wi-Fi networks defined in the Network+ objectives and is more commonly associated with legacy cordless phones and certain IoT or proprietary wireless technologies.
Network+ troubleshooting guidance emphasizes identifying environmental interference sources when diagnosing intermittent wireless connectivity. A common mitigation strategy is to migrate affected devices to the 5GHz or 6GHz bands or reposition access points away from interference sources like break room appliances.
After installing a new 6E wireless router in a small office, a technician notices that some wireless devices are not able to achieve the rated speeds.
Which of the following should the technician check to troubleshoot the issue? (Select two)
- A . Client device compatibility
- B . Back-end cabling
- C . Weather phenomena
- D . Voltage source requirements
- E . Interference levels
- F . Processing power
Which of the following protocols uses the Dijkstra’s Link State Algorithm to establish routes inside its routing table?
- A . OSPF
- B . EIGRP
- C . BGP
- D . RIP
A
Explanation:
OSPF (Open Shortest Path First) is a link-state routing protocol that uses the Dijkstra algorithm, also known as the shortest path first (SPF) algorithm, to determine the most efficient routes.
From Andrew Ramdayal’s guide:
“OSPF is a link-state routing protocol that provides fast, efficient path selection using the shortest path first (SPF) algorithm.”
A network engineer configures a NIC that has an IP address of 192.168.123.232.
Which of the following classes is this address an example of?
- A . Class A
- B . Class B
- C . Class C
- D . Class D
C
Explanation:
The IPv4 address 192.168.123.232 falls within the Class C range under classful addressing. In classful terms, Class C addresses have a first octet from 192 to 223, which makes any address starting with 192.x.x.x a Class C address. Network+ (N10-009) networking concepts cover IPv4 addressing fundamentals and commonly reference class ranges as foundational knowledge, even though modern networks primarily use CIDR (classless) subnetting rather than strict classful boundaries.
This address is also within a well-known private IPv4 block: 192.168.0.0/16 (RFC1918 private addressing), which is frequently used for internal networks and NIC configurations where addresses are not routable on the public internet.
To eliminate the distractors: Class A uses first octet 1C126, Class B uses 128C191, and Class D (224C 239) is reserved for multicast. Since the first octet here is 192, it maps to Class C, making option C correct.
Which of the following is the MOST appropriate solution to extend the network to a building located across the street from the main facility?
- A . Multimode fiber
- B . 802.11ac wireless bridge
- C . Cat 6 copper
- D . Loopback adapter
B
Explanation:
An 802.11ac wireless bridge is the most practical solution to connect two nearby buildings without trenching or laying physical cable. It provides high-speed, point-to-point connectivity using directional antennas.
A small business is deploying new phones, and some of the phones have full HD videoconferencing features. The Chief Information Officer (CIO) is concerned that the network might not be able to handle the traffic if it reaches a certain threshold.
Which of the following can the network engineer configure to help ease these concerns?
- A . A VLAN with 100Mbps speed limits
- B . An IP helper to direct VoIP traffic
- C . A smaller subnet mask
- D . Full duplex on all user ports
D
Explanation:
Full duplex mode allows devices to send and receive data simultaneously, improving network performance and reducing congestion, which is critical for VoIP and video conferencing.
Breakdown of Options:
A company receives a cease-and-desist order from its ISP regarding prohibited torrent activity.
Which of the following should be implemented to comply with the cease-and-desist order?
- A . MAC security
- B . Content filtering
- C . Screened subnet
- D . Perimeter network
B
Explanation:
Content filtering can be used to block or restrict access to websites and services that facilitate torrenting and other prohibited activities. By implementing content filtering, the company can comply with the ISP’s cease-and-desist order and prevent users from accessing torrent sites and engaging in prohibited activities.
Reference: CompTIA Network+ study materials.
Which of the following protocols has a default administrative distance value of 90?
- A . RIP
- B . EIGRP
- C . OSPF
- D . BGP
B
Explanation:
EIGRP (Enhanced Interior Gateway Routing Protocol) has a default administrative distance (AD) value of 90 for internal routes. The administrative distance is used to rate the trustworthiness of routing information received from different routing protocols. EIGRP, developed by Cisco, has an AD of 90, which is lower than that of RIP (120) and OSPF (110), making it more preferred if multiple protocols provide a route to the same destination.
Reference: CompTIA Network+ study materials.
Which of the following physical installation factors is the most important when a network switch is installed in a sealed enclosure?
- A . Fire suppression
- B . Power budget
- C . Temperature
- D . Humidity
C
Explanation:
Switches in sealed enclosures are at risk of overheating because airflow is restricted. The temperature factor is critical since heat buildup can damage components, shorten device lifespan, and cause outages. Proper cooling or ventilation must be ensured.