N10-009 Exam Dumps - CompTIA Network+ Certification Exam

The default gateway for a network should be an IP address within the subnet, but not the broadcast address. In this case:

IP: 192.163.1.15

Subnet Mask: 255.255.255.0

This means the network range is: 192.163.1.0 - 192.163.1.255

192.163.1.255 is the broadcast address for this subnet, so it cannot be used as a gateway.

Hence, the device fails to communicate outside its subnet because it ' s trying to use a broadcast address as its gateway.

✅ The issue is clearly with the gateway configuration.

The correct answer is The port ' s VLAN assignment on the switch because the symptoms indicate a Layer 2 segmentation issue. According to CompTIA Network+ (N10-009) troubleshooting methodology and VLAN concepts, if the IP configuration is correct and the TCP/IP stack is functioning, but the default gateway is unreachable, the issue often involves improper VLAN configuration.

In a switched environment, devices must be assigned to the correct VLAN to communicate with the appropriate default gateway interface (often configured on a router or Layer 3 switch). If the user’s switch port is assigned to the wrong VLAN, the workstation may have a valid IP address but will not be able to reach the gateway because it is logically separated into a different broadcast domain.

Option A is unlikely since the IP configuration is already confirmed correct. Option C is not relevant because the issue is localized to a specific user, not a widespread DHCP failure. Option D refers to switch management configuration, which does not affect user traffic routing to the gateway.

Therefore, verifying the switch port’s VLAN assignment is the most appropriate next troubleshooting step.

Spanning Tree Protocol (STP) is designed to detect and prevent Layer 2 loops by blocking redundant paths. If loops are possible in the design, enabling STP ensures network stability.

B. Port security controls endpoint MAC addresses, not loops.

C. Speed limits address bandwidth, not loop prevention.

D. 802.1Q tagging allows VLAN separation but does not resolve loops.

References (CompTIA Network+ N10-009):

Domain: Network Operations — Loop prevention, spanning tree, switch design.

The correct answer is A. Channel overlap . The signal strength numbers given, -50 to -65 dBm , are generally strong enough for normal client connectivity, so this does not point to weak coverage. The bigger clue is that the environment is a multitenant office building and the wireless network is using 2.4 GHz . That band is well known for congestion and overlapping channels, especially where many nearby businesses or tenants have their own access points.

In the 2.4 GHz range, there are only a few non-overlapping channels commonly used. When many APs operate close together on overlapping channels, clients can experience interference, retransmissions, poor throughput, buffering, and connection instability. Those symptoms fit the scenario very well.

The other options are less convincing. Insufficient wireless coverage does not line up with the reported signal levels. AP antenna type could matter in some designs, but there is nothing in the question pointing to a directional or placement issue. WPA2 is not the cause of the performance symptoms here; while it is older than WPA3, it does not normally create repeated buffering and disconnections in this way.

This is really a wireless interference question, and in a crowded 2.4 GHz building, channel overlap is the most likely reason.

The MPO (Multi-fiber Push On) connector is designed to handle multiple fiber strands in a single connector, and it is commonly used with high-density transceivers like QSFP (Quad Small Form-factor Pluggable).

QSFP can support up to four channels (hence " quad " ), and MPO connectors can interface multiple fibers (e.g., 8, 12, 24), making them ideal for 40Gbps or 100Gbps deployments.

RJ45 (A) is used for Ethernet over copper.

ST (B) and LC (C) are single-fiber connectors — they don ' t support the multi-fiber needs of QSFP setups.

✅ Therefore, MPO is the correct connector type for this use case.