CompTIA Updated N10-009 Exam Questions and Answers by natan

Quality of Service (QoS): This is a feature used in networking to prioritize certain types of traffic. By configuring QoS, network administrators can allocate higher bandwidth to time-sensitive applications like VoIP, video conferencing, or critical business applications during peak usage times. This helps to reduce latency and packet loss, which are often caused by congestion.

Load Balancing (A): While load balancing is useful in distributing traffic across multiple servers or paths, it does not address congestion on a single switch.

Port Mirroring (B): This is used for monitoring network traffic for troubleshooting and diagnostics but does not alleviate congestion.

Spanning Tree Protocol (D): STP prevents switching loops in redundant network topologies, but it is not designed to handle traffic prioritization or congestion issues.

WPA2/WPA3 mixed mode provides compatibility for older devices (that only support WPA2) while allowing newer devices to take advantage of stronger WPA3 encryption. This ensures maximum compatibility and security in a mixed-device environment.

A. WPA3 only is most secure but not compatible with legacy devices.

B. WPA2 only is secure but does not future-proof against WPA3-capable devices.

D. WPA/WPA2 mixed mode is weaker due to WPA (deprecated, insecure).

References (CompTIA Network+ N10-009):

Domain: Network Security — Wi-Fi encryption standards, WPA2 vs WPA3, mixed-mode compatibility.

In the router route selection process, the first priority is the longest prefix match, also known as prefix length. According to CompTIA Network+ (N10-009) routing concepts, routers examine the destination IP address in the packet and compare it to entries in the routing table. When multiple routes exist, the router selects the route with the most specific match, meaning the route with the longest subnet mask (largest number of matching bits). For example, a /30 route is preferred over a /24, and a /24 is preferred over a /16 if all match the destination.

Only after the longest prefix match is determined do other factors come into play. Administrative distance (AD) is used to determine which routing source is more trustworthy when the same network is learned from different routing protocols (e.g., OSPF vs. RIP). Metric is then used within the same routing protocol to determine the best path (e.g., hop count, cost, bandwidth). A default route (0.0.0.0/0) is used only when no more specific match exists.

Therefore, prefix length is always evaluated first in route selection.

The errors described — dropped packets and CRC (Cyclic Redundancy Check) errors — often indicate electromagnetic interference (EMI) on unshielded twisted pair (UTP) cabling. The correct replacement is STP (Shielded Twisted Pair), which has shielding that protects signals from external interference, ensuring better reliability in noisy environments such as data centers or near heavy electrical equipment.

A. Coaxial is not used for modern Ethernet server-switch links.

B. Shorter UTP cable does not solve EMI issues.

C. Plenum cable refers to cable jacket type for fire safety, not electrical shielding.

STP cabling reduces interference and ensures reliable gigabit+ Ethernet connections between servers and switches.

References (CompTIA Network+ N10-009):

Domain: Network Troubleshooting — Cabling issues, UTP vs. STP, EMI.