CompTIA Updated N10-009 Exam Questions and Answers by cory

A /25 subnet mask means 25 bits are reserved for the network portion, leaving 7 bits for host addresses. In dotted decimal, that is:

11111111.11111111.11111111.10000000

Decimal equivalent: 255.255.255.128

A. 255.255.254.0 corresponds to /23.

B. 255.255.255.1 is invalid as a subnet mask.

D. 255.255.255.192 corresponds to /26.

Thus, the correct subnet mask for a /25 network is 255.255.255.128.

References (CompTIA Network+ N10-009):

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

The correct answer is SNMP (Simple Network Management Protocol) because it is specifically designed to collect and transmit network management and status information between managed devices and management systems. According to CompTIA Network+ (N10-009) objectives, SNMP is used for monitoring and managing network devices such as routers, switches, servers, and printers.

SNMP operates using a manager-agent model. The SNMP manager (such as a network monitoring server) communicates with SNMP agents installed on network devices. Agents send traps and inform messages, which are unsolicited status alerts indicating events such as device failures, high CPU usage, or link outages. The manager can also poll agents to retrieve performance metrics and configuration details stored in the Management Information Base (MIB).

SSH (Option A) is used for secure remote administration. DHCP (Option B) dynamically assigns IP addresses. NTP (Option C) synchronizes time between devices. None of these protocols are designed for network status monitoring and alert messaging.

Therefore, SNMP is the correct protocol for sending networking status messages between devices and management systems.

Bottom of Form

UESTION NO: 21 [Network Infrastructure]

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

Answer: C

The correct answer is Temperature because a sealed enclosure restricts airflow, which can cause heat to accumulate rapidly. According to CompTIA Network+ (N10-009) objectives under physical installations and environmental factors, maintaining proper temperature control is critical for network equipment reliability and longevity.

Network switches generate heat during operation, particularly models with high port density or Power over Ethernet (PoE) capabilities. In a sealed enclosure without proper ventilation or cooling mechanisms, excessive heat buildup can lead to thermal throttling, unexpected shutdowns, hardware degradation, or permanent equipment failure. Manufacturers specify operating temperature ranges, and exceeding these limits significantly reduces device lifespan and performance.

While humidity (Option D) is important to prevent condensation and corrosion, temperature fluctuations pose a more immediate risk in a sealed environment. Power budget (Option B) is relevant when calculating PoE load capacity but does not directly address environmental installation conditions. Fire suppression (Option A) is important in data centers but is not the primary concern specific to a sealed enclosure scenario.

Therefore, ensuring proper temperature management is the most critical installation factor.

PAT (Port Address Translation) allows multiple devices on a local network to share a single public IP address when accessing the internet. It translates the private IP addresses to a single public IP with different port numbers for each session. The document states:

“PAT (Port Address Translation) allows multiple devices on a LAN to share a single public IP address by assigning unique port numbers to each session, enabling internet connectivity for all devices.”

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. A VLAN with 100Mbps speed limits – VLANs segment traffic but limiting speeds to 100Mbps would worsen video performance.

B. An IP helper to direct VoIP traffic – IP helper is used for DHCP relay, not for VoIP optimization.

C. A smaller subnet mask – A smaller subnet reduces IP address availability but does not improve network performance.

D. Full duplex on all user ports – Correct answer. Full duplex eliminates collisions, allowing better VoIP and video performance.