This scenario describes a duplicate IP address. The ARP table shows two different MAC addresses (0c00.1134.0001 and 0c00.1298.d239) associated with the same IP address (192.168.1.10), which leads to ARP table conflicts and intermittent connectivity.

From Andrew Ramdayal’s guide:

“Duplicate IP addresses occur when two devices on the same network are assigned the same IP address, causing network conflicts. Common issues include manual configuration errors or DHCP lease issues. Resolution includes using IP management tools and avoiding overlaps in DHCP and static IP assignments.”

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.

A Power Distribution Unit (PDU) provides multiple power outlets in a data center or IDF (Intermediate Distribution Frame), while offering features like surge protection, load balancing, and sometimes remote monitoring, making it a cost-effective and reliable solution. The document confirms:

“PDUs (Power Distribution Units) are a cost-effective way to expand outlet capacity in a structured cabling environment like an IDF. They ensure safe power delivery to networking equipment and often include monitoring features.”

The correct answer is ACL (Access Control List). According to the CompTIA Network+ N10-009 objectives, ACLs are a fundamental and cost-effective method for controlling traffic flow at routers and firewalls. An ACL allows administrators to permit or deny traffic based on source IP address, destination IP address, protocol, or port number.

In this scenario, the suspicious traffic is identified as originating from a specific unknown foreign IP address. The most direct and economical mitigation strategy is to configure an ACL rule that denies traffic from that specific IP address (or subnet) at the network perimeter. This approach leverages existing network infrastructure without requiring additional hardware or licensing costs.

An IDS (Intrusion Detection System) monitors and alerts on malicious activity but does not actively block traffic unless paired with IPS functionality, and it may involve additional cost and complexity. NAT is used for address translation and does not provide traffic filtering based on threat intelligence. DoS prevention solutions are typically more advanced, specialized, and costly, often intended for large-scale distributed denial-of-service attacks rather than blocking traffic from a single suspicious IP.

The Network+ objectives emphasize implementing layered security controls, starting with simple and effective measures. In this case, applying an ACL at the firewall or router is the most cost-efficient and immediate method to mitigate the identified threat.

The correct answer is Power redundancy because the devices in the rack are equipped with dual power supplies, which are specifically designed to support redundant power sources. According to CompTIA Network+ (N10-009) objectives under high availability and physical infrastructure concepts, redundancy is a key strategy to eliminate single points of failure.

If only one PDU (Power Distribution Unit) is installed, both power supplies from each device may ultimately rely on the same power source. This creates a single point of failure—if the PDU fails or loses upstream power, all connected equipment will shut down despite having dual power supplies.

By installing a second PDU connected to a separate power circuit (and ideally a separate UPS or power feed), each power supply in the servers and switches can connect to different PDUs. If one PDU fails, the other continues delivering power, ensuring uninterrupted operation.

Option B (Failed PSU monitoring) is not the primary reason for adding another PDU. Option C (Surge protection) can be provided by a single PDU. Option D (Electricity conservation) is unrelated to redundancy design.

Therefore, adding a second PDU provides true power redundancy.

Comprehensive and Detailed Explanation (paraphrased, aligned to N10-009):

In a spine–leaf architecture, endpoints (including servers, firewalls, and WAN/edge routers) connect to leaf switches. Leaf switches then uplink to spine switches; spine switches do not have endpoints connected directly to them. Therefore, a WAN router (an external/edge device) should connect to the leaf layer—often specifically to a “border leaf” that handles external connectivity.

Why not B. Core or D. Spine? In spine–leaf, “core” isn’t a formal layer, and spines are designed only to interconnect leafs, not to terminate endpoints.

Why not A. Access? “Access” is a term from the traditional three-tier model (access–distribution–core). In modern spine–leaf language, the analogous layer for endpoint attachment is the leaf.

References (CompTIA Network+ N10-009):

Domain: Network Infrastructure — Data center and campus architectures (spine–leaf vs. three-tier), roles of leaf/spine, WAN/edge connectivity points.

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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 solution is to configure the connecting ports as trunk ports. When connecting switches, the uplink ports must be configured to carry traffic for multiple VLANs (trunking), not just a single access VLAN. Without trunking, VLAN tags may be dropped, and traffic from hosts will not reach the rest of the network or internet.

B. STP cables is a misnomer — STP refers to Spanning Tree Protocol or Shielded Twisted Pair cables, neither of which solves this logical configuration issue.

C. PoE budget is irrelevant because switches and hosts in this context don’t require PoE.

D. Link aggregation (LACP, EtherChannel) is for increasing bandwidth/redundancy across multiple links, not required with a single cable.

By enabling trunking on the uplink ports, the switches can pass VLAN-tagged traffic, ensuring hosts connected to the new switch have access to the same resources as those on the existing switch.

References (CompTIA Network+ N10-009):

Domain: Network Troubleshooting — VLAN trunking, inter-switch connectivity.

Introduction to Administrative Distance

Administrative distance (AD) is a value used by routers to rank routes from different routing protocols. AD represents the trustworthiness of the source of the route. Lower AD values are more preferred. If a router has multiple routes to a destination from different sources, it will choose the route with the lowest AD.

Static Routes and Backup Routes

When a dynamic routing protocol is not used, static routes can be employed. Static routes are manually configured routes. To ensure a backup route, multiple static routes to the same destination can be configured with different AD values.

Configuring Static Routes with Administrative Distance

The primary route is configured with a lower AD value, making it the preferred route. The backup route is configured with a higher AD value. In the event of the primary route failure, the router will then use the backup route.

Example Configuration:

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ip route 192.168.1.0 255.255.255.0 10.0.0.1 1

ip route 192.168.1.0 255.255.255.0 10.0.0.2 10

In the above example, 192.168.1.0/24 is the destination network.

10.0.0.1 is the next-hop IP address for the primary route with an AD of 1.

10.0.0.2 is the next-hop IP address for the backup route with an AD of 10.

Verification:

After configuration, use the show ip route command to verify that the primary route is in use and the backup route is listed as a candidate for use if the primary route fails.

Role of an Access Point (AP):

Wireless to Wired Conversion: An access point (AP) is a device that allows wireless devices to connect to a wired network using Wi-Fi. It converts wireless signals (radio waves) into electronic signals that can be understood by wired network devices.

Functionality:

Signal Conversion: The AP receives wireless signals from devices such as laptops, smartphones, and tablets, converts them into electronic signals, and transmits them over the wired network.

Connectivity: APs provide a bridge between wireless and wired segments of the network, enabling seamless communication.

Comparison with Other Devices:

Router: Directs traffic between different networks and may include built-in AP functionality but is not primarily responsible for converting wireless to electronic signals.

Firewall: Protects the network by controlling incoming and outgoing traffic based on security rules, not involved in signal conversion.

Load Balancer: Distributes network or application traffic across multiple servers to ensure reliability and performance, not involved in signal conversion.

Deployment:

APs are commonly used in environments where wireless connectivity is needed, such as offices, homes, and public spaces. They enhance mobility and provide flexible network access.

A golden configuration is a baseline configuration file that contains approved, standardized settings for network devices. The purpose is to ensure configuration consistency across the environment. This prevents misconfigurations, supports compliance with organizational or regulatory standards, and accelerates recovery if a device needs reconfiguration.

B. Reducing file size is not the goal of golden configs.

C. Golden configs can include security settings, but they are not inherently encrypted — they are simply a baseline template.

D. While configs can be backed up, golden configs are more about standardization, not device-specific backups.

By maintaining a golden configuration, administrators can quickly detect unauthorized changes (by comparing running configs against the golden file) and enforce consistency across devices. This improves network stability, reduces troubleshooting complexity, and enhances security posture.

References (CompTIA Network+ N10-009):

Domain: Network Operations — Configuration management, golden images/configurations.

Devices in both buildings should be able to access the Internet.

Security insists that all Internet traffic be inspected before entering the network.

Desktops should not see traffic destined for other devices.

Here is the corrected layout with explanation:

Building A:

Switch: Correctly placed to connect all desktops.

Firewall: Correctly placed to inspect all incoming and outgoing traffic.

Building B:

Switch: Not needed. Instead, place a Wireless Access Point (WAP) to provide wireless connectivity for laptops and mobile devices.

Between Buildings:

Wireless Range Extender: Correctly placed to provide connectivity between the buildings wirelessly.

Connection to the Internet:

Router: Correctly placed to connect to the Internet and route traffic between the buildings and the Internet.

Firewall: The firewall should be placed between the router and the internal network to inspect all traffic before it enters the network.

Corrected Setup:

Top-left (Building A): Switch

Bottom-left (Building A): Firewall (inspect traffic before it enters the network)

Top-middle (Internet connection): Router

Bottom-middle (between buildings): Wireless Range Extender

Top-right (Building B): Wireless Access Point (WAP)

In this corrected setup, the WAP in Building B will connect wirelessly to the Wireless Range Extender, which is connected to the Router. The Router is connected to the Firewall to ensure all traffic is inspected before it enters the network.

Configuration for Wireless Range Extender:

SSID: CORP

Security Settings: WPA2 or WPA2 - Enterprise

Key or Passphrase: [Enter a strong passphrase]

Mode: [Set based on your network plan]

Channel: [Set based on your network plan]

Speed: Auto

Duplex: Auto

With these settings, both buildings will have secure access to the Internet, and all traffic will be inspected by the firewall before entering the network. Desktops and other devices will not see traffic intended for others, maintaining the required security and privacy.

To configure the wireless range extender for security, follow these steps:

SSID (Service Set Identifier):

Ensure the SSID is set to " CORP " as shown in the exhibit.

Security Settings:

WPA2 or WPA2 - Enterprise: Choose one of these options for stronger security. WPA2-Enterprise provides more robust security with centralized authentication, which is ideal for a corporate environment.

Key or Passphrase:

If you select WPA2, enter a strong passphrase in the " Key or Passphrase " field.

If you select WPA2 - Enterprise, you will need to configure additional settings for authentication servers, such as RADIUS, which is not shown in the exhibit.

Wireless Mode and Channel:

Set the appropriate mode and channel based on your network design and the environment to avoid interference. These settings are not specified in the exhibit, so set them according to your network plan.

Wired Speed and Duplex:

Set the speed to " Auto " unless you have specific requirements for 100 or 1000 Mbps.

Set the duplex to " Auto " unless you need to specify half or full duplex based on your network equipment.

Save Configuration:

After making the necessary changes, click the " Save " button to apply the settings.

Here is how the configuration should look after adjustments:

SSID: CORP

Security Settings: WPA2 or WPA2 - Enterprise

Key or Passphrase: [Enter a strong passphrase]

Mode: [Set based on your network plan]

Channel: [Set based on your network plan]

Speed: Auto

Duplex: Auto

Once these settings are configured, your wireless range extender will provide secure connectivity for devices in both buildings.

Firewall setting to to ensure complete compliance with the requirements and best security practices, consider the following adjustments and additions:

DNS Rule: This rule allows DNS traffic from the internal network to any destination, which is fine.

HTTPS Outbound: This rule allows HTTPS traffic from the internal network (assuming 192.169.0.1/24 is a typo and should be 192.168.0.1/24) to any destination, which is also good for secure web browsing.

Management: This rule allows SSH access to the firewall for management purposes, which is necessary for administrative tasks.

HTTPS Inbound: This rule denies inbound HTTPS traffic to the internal network, which is good unless you have a web server that needs to be accessible from the internet.

HTTP Inbound: This rule denies inbound HTTP traffic to the internal network, which is correct for security purposes.

Suggested Additional Settings:

Permit General Outbound Traffic: Allow general outbound traffic for web access, email, etc.

Block All Other Traffic: Ensure that all other traffic is blocked to prevent unauthorized access.

Firewall Configuration Adjustments:

Correct the Network Typo:

Ensure that the subnet 192.169.0.1/24 is corrected to 192.168.0.1/24.

Permit General Outbound Traffic:

Rule Name: General Outbound

Source: 192.168.0.1/24

Destination: ANY

Service: ANY

Action: PERMIT

Deny All Other Traffic:

Rule Name: Block All

Source: ANY

Destination: ANY

Service: ANY

Action: DENY

Here is how your updated firewall settings should look:

Rule Name

Source

Destination

Service

Action

DNS Rule

192.168.0.1/24

ANY

DNS

PERMIT

HTTPS Outbound

192.168.0.1/24

ANY

HTTPS

PERMIT

Management

ANY

192.168.0.1/24

SSH

PERMIT

HTTPS Inbound

ANY

192.168.0.1/24

HTTPS

DENY

HTTP Inbound

ANY

192.168.0.1/24

HTTP

DENY

General Outbound

192.168.0.1/24

ANY

ANY

PERMIT

Block All

ANY

ANY

ANY

DENY

These settings ensure that:

Internal devices can access DNS and HTTPS services externally.

Management access via SSH is permitted.

Inbound HTTP and HTTPS traffic is denied unless otherwise specified.

General outbound traffic is allowed.

All other traffic is blocked by default, ensuring a secure environment.

Make sure to save the settings after making these adjustments.

A jump box is a hardened system that provides secure access to isolated or sensitive devices on a separate network.

Breakdown of Options:

A. Jump box – ✅ Correct answer. Acts as a middle point for secure remote access.

B. API gateway – Used for managing API calls, not remote access to isolated devices.

C. Secure Shell (SSH) – Requires direct connectivity, which may not be available for an isolated device.

D. Clientless VPN – Allows web-based VPN access, but does not guarantee access to isolated devices.

When configuring a firewall, the first step is identifying which ports, protocols, and services are required for normal business operations. This ensures only legitimate traffic is allowed. After establishing the required rules, a default deny rule is added for security.

B. Deny all rule is important, but it should come after defining required rules.

C. VPN access is a service to configure, but only after determining baseline needs.

D. Outbound traffic policies are part of refinement, not the first consideration.

References (CompTIA Network+ N10-009):

Domain: Network Security — Firewall configuration, rule order, least privilege.

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.