Practice Free N10-009 Exam Online Questions
Ten new laptops are added to an existing network, and they can only communicate with one another.
An administrator reviews documentation and sees the following:
Subnet: 10.8.100.1/24
Scope: 10.8.100.50 C 10.8.100.150
Reservation: 10.8.100.151 C 10.8.100.175
A technician scans the network and receives the following results:
IP addresses used: 10.8.100.45 C 10.8.100.175
Which of the following should be done to ensure connectivity on all laptops?
- A . Increase the scope to 10.8.100.35 C 10.8.100.150
- B . Increase the scope to 10.8.100.40 C 10.8.100.150
- C . Increase the scope to 10.8.100.40 C 10.8.100.175
- D . Increase the scope to 10.8.100.50 C 10.8.100.175
D
Explanation:
The correct answer is D: Increase the scope to 10.8.100.50 C 10.8.100.175. According to the CompTIA Network+ N10-009 objectives, proper DHCP scope configuration is essential to ensure all hosts can obtain valid IP addresses and communicate beyond their local segment.
In this scenario, the DHCP scope is configured for 10.8.100.50 through 10.8.100.150, while a reservation range exists from 10.8.100.151 through 10.8.100.175. The network scan shows that IP addresses up to 10.8.100.175 are already in use. This indicates that some devices are either statically assigned addresses outside the active scope or are failing to receive valid DHCP leases, causing the new laptops to communicate only with each other―often a sign of APIPA or improper addressing.
To ensure full connectivity, the DHCP scope must be expanded to include the entire range of addresses that are actively in use, including the reserved addresses.
Option D correctly extends the scope to 10.8.100.175 without overlapping lower addresses that may be statically assigned or intentionally excluded.
The Network+ objectives emphasize avoiding address conflicts and ensuring DHCP scopes align with real-world network usage. Expanding the scope to include all valid addresses ensures that all laptops can obtain proper IP configuration, default gateway information, and full network connectivity.
Which of the following disaster recovery metrics is used to describe the amount of data that is lost since the last backup?
- A . MTTR
- B . RTO
- C . RPO
- D . MTBF
C
Explanation:
Definition of RPO:
Recovery Point Objective (RPO) is a disaster recovery metric that describes the maximum acceptable amount of data loss measured in time. It indicates the point in time to which data must be recovered to resume normal operations after a disaster.
For example, if the RPO is set to 24 hours, then the business could tolerate losing up to 24 hours’ worth of data in the event of a disruption.
Why RPO is Important:
RPO is critical for determining backup frequency and helps businesses decide how often they need to back up their data. A lower RPO means more frequent backups and less potential data loss.
Comparison with Other Metrics:
MTTR (Mean Time to Repair): Refers to the average time required to repair a system or component and return it to normal operation.
RTO (Recovery Time Objective): The maximum acceptable length of time that a computer, system, network, or application can be down after a failure or disaster occurs.
MTBF (Mean Time Between Failures): The predicted elapsed time between inherent failures of a system during operation.
How RPO is Used in Disaster Recovery:
Organizations establish RPOs to ensure that they can recover data within a timeframe that is acceptable to business operations. This involves creating a backup plan that meets the RPO requirements.
Reference: CompTIA Network+ study materials and certification guides.
After a security incident, a technician reveals that company data was stolen. During the investigation, it is discovered that a host disguised itself as a switch.
Which of the following best describes the attack that occurred?
- A . VLAN hopping
- B . Evil twin
- C . DNS poisoning
- D . ARP spoofing
A
Explanation:
VLAN hopping occurs when an attacker tricks a switch into believing the host is another switch by generating tagged frames or exploiting trunk negotiation (DTP). This allows the attacker to access traffic from multiple VLANs, potentially stealing sensitive data.
B. Evil twin is a rogue wireless AP attack, unrelated to switch impersonation.
C. DNS poisoning corrupts name resolution, not VLAN access.
D. ARP spoofing is a Layer 2 on-path attack, not masquerading as a switch.
Reference (CompTIA Network+ N10-009):
Domain: Network Security ― VLAN hopping attacks, switch spoofing techniques.
A network engineer is installing new PoE wireless APs. The first five APs deploy successfully, but the sixth one fails to start.
Which of the following should the engineer investigate first?
- A . Signal strength
- B . Duplex mismatch
- C . Power budget
- D . CRC
C
Explanation:
When deploying multiple Power over Ethernet (PoE) devices, the switch’s power budget can be exhausted. If the available wattage on the switch cannot supply the additional AP, it will fail to power on. This is the most likely cause when previous APs worked fine but a new one does not.
A network administrator recently upgraded a wireless infrastructure with new APs. Users report that when stationary, the wireless connection drops and reconnects every 20 to 30 seconds. While reviewing logs, the administrator notices the APs are changing channels.
Which of the following is the most likely reason for the service interruptions?
- A . Channel interference
- B . Roaming misconfiguration
- C . Network congestion
- D . Insufficient wireless coverage
A
Explanation:
If APs are changing channels frequently, it indicates automatic channel selection due to interference.
This can cause temporary disconnections as the APs switch frequencies.
Breakdown of Options:
A network administrator recently upgraded a wireless infrastructure with new APs. Users report that when stationary, the wireless connection drops and reconnects every 20 to 30 seconds. While reviewing logs, the administrator notices the APs are changing channels.
Which of the following is the most likely reason for the service interruptions?
- A . Channel interference
- B . Roaming misconfiguration
- C . Network congestion
- D . Insufficient wireless coverage
A
Explanation:
If APs are changing channels frequently, it indicates automatic channel selection due to interference.
This can cause temporary disconnections as the APs switch frequencies.
Breakdown of Options:
Which of the following is most closely associated with having a leased line to a public cloud provider?
- A . VPN
- B . Direct Connect
- C . Internet gateway
- D . Private cloud
B
Explanation:
Direct Connect is the option most closely associated with having a leased line to a public cloud provider, as defined in the CompTIA Network+ N10-009 objectives under cloud connectivity and WAN technologies. Direct Connect (or equivalent services such as Azure ExpressRoute or Google Cloud Interconnect) provides a dedicated, private physical connection between an organization’s on-premises network and a public cloud provider’s infrastructure. This connection bypasses the public internet, offering consistent bandwidth, lower latency, improved performance, and enhanced security.
A VPN uses encrypted tunnels over the public internet, which does not qualify as a leased line and is subject to internet congestion and variable performance. An internet gateway simply allows cloud resources to communicate with the public internet and does not imply a private or dedicated connection. A private cloud refers to a deployment model where cloud resources are dedicated to a
single organization; it does not describe the connectivity method or the use of a leased circuit.
According to Network+ objectives, leased-line connectivity to cloud providers is commonly used by enterprises that require high availability, predictable throughput, regulatory compliance, or secure hybrid cloud architectures. Direct Connect is a foundational component of hybrid networking strategies, linking on-premises environments directly to public cloud services using provider-managed circuits.
A network administrator is connecting two Layer 2 switches in a network. These switches must transfer data in multiple networks.
Which of the following would fulfill this requirement?
- A . Jumbo frames
- B . 802.1Q tagging
- C . Native VLAN
- D . Link aggregation
B
Explanation:
A network technician is working on a PC with a faulty NIC. The host is connected to a switch with secured ports. After testing the connection cables and using a known-good NIC, the host is still unable to connect to the network.
Which of the following is causing the connection issue?
- A . MAC address of the new card
- B . BPDU guard settings
- C . Link aggregation settings
- D . PoE power budget
A
Explanation:
If a switch has port security enabled (such as sticky MAC or a configured allowed MAC), the port will only allow the original NIC’s MAC address. When a new NIC with a different MAC address is installed, the port rejects traffic, preventing network connectivity.
B. BPDU guard protects against rogue switches, not end hosts.
C. Link aggregation applies when bundling multiple uplinks, not a single PC connection.
D. PoE budget applies to powered devices like APs, not PCs.
Reference (CompTIA Network+ N10-009):
Domain: Network Troubleshooting ― Port security, MAC address filtering, switch security features.
A network technician is working on a PC with a faulty NIC. The host is connected to a switch with secured ports. After testing the connection cables and using a known-good NIC, the host is still unable to connect to the network.
Which of the following is causing the connection issue?
- A . MAC address of the new card
- B . BPDU guard settings
- C . Link aggregation settings
- D . PoE power budget
A
Explanation:
If a switch has port security enabled (such as sticky MAC or a configured allowed MAC), the port will only allow the original NIC’s MAC address. When a new NIC with a different MAC address is installed, the port rejects traffic, preventing network connectivity.
B. BPDU guard protects against rogue switches, not end hosts.
C. Link aggregation applies when bundling multiple uplinks, not a single PC connection.
D. PoE budget applies to powered devices like APs, not PCs.
Reference (CompTIA Network+ N10-009):
Domain: Network Troubleshooting ― Port security, MAC address filtering, switch security features.