Practice Free N10-009 Exam Online Questions
Which of the following tools uses ICMP to help determine whether a network host is reachable?
- A . tcpdump
- B . netstat
- C . nslookup
- D . ping
D
Explanation:
Ping sends ICMP Echo Request packets and waits for Echo Replies to verify host reachability and measure round-trip time.
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.
Which of the following disaster recovery concepts is calculated by dividing the total hours of operation by the total number of units?
- A . MTTR
- B . MTBF
- C . RPO
- D . RTO
B
Explanation:
Introduction to Disaster Recovery Concepts:
Disaster recovery involves strategies and measures to ensure business continuity and data recovery in the event of a disaster.
Mean Time Between Failures (MTBF):
MTBF is a reliability metric used to predict the time between failures of a system during operation. It is calculated by dividing the total operational time by the number of failures.
Formula: MTBF=Total Operational TimeNumber of Failurestext{MTBF} = frac{text{Total Operational Time}}{text{Number of Failures}}MTBF=Number of FailuresTotal Operational Time This metric helps in understanding the reliability and expected lifespan of systems and components.
Example Calculation:
If a server operates for 1000 hours and experiences 2 failures, the MTBF is:
MTBF=1000 hours2=500 hourstext{MTBF} = frac{1000 text{ hours}}{2} = 500 text{
hours}MTBF=21000 hours =500 hours
Explanation of the Options:
Which of the following disaster recovery concepts is calculated by dividing the total hours of operation by the total number of units?
- A . MTTR
- B . MTBF
- C . RPO
- D . RTO
B
Explanation:
Introduction to Disaster Recovery Concepts:
Disaster recovery involves strategies and measures to ensure business continuity and data recovery in the event of a disaster.
Mean Time Between Failures (MTBF):
MTBF is a reliability metric used to predict the time between failures of a system during operation. It is calculated by dividing the total operational time by the number of failures.
Formula: MTBF=Total Operational TimeNumber of Failurestext{MTBF} = frac{text{Total Operational Time}}{text{Number of Failures}}MTBF=Number of FailuresTotal Operational Time This metric helps in understanding the reliability and expected lifespan of systems and components.
Example Calculation:
If a server operates for 1000 hours and experiences 2 failures, the MTBF is:
MTBF=1000 hours2=500 hourstext{MTBF} = frac{1000 text{ hours}}{2} = 500 text{
hours}MTBF=21000 hours =500 hours
Explanation of the Options:
Which of the following devices can operate in multiple layers of the OSI model?
- A . Hub
- B . Switch
- C . Transceiver
- D . Modem
B
Explanation:
Understanding Switches:
Layer 2 (Data Link Layer): Traditional switches operate primarily at Layer 2, where they use MAC addresses to forward frames within a local network.
Layer 3 (Network Layer): Layer 3 switches, also known as multilayer switches, can perform routing functions using IP addresses to forward packets between different networks. Capabilities of Multilayer Switches:
VLANs and Inter-VLAN Routing: Multilayer switches can handle VLAN (Virtual Local Area Network)
configurations and perform inter-VLAN routing, enabling communication between different VLANs. Routing Protocols: They can run routing protocols like OSPF (Open Shortest Path First) and EIGRP (Enhanced Interior Gateway Routing Protocol) to manage traffic between networks. Comparison with Other Devices:
Hub: Operates only at Layer 1 (Physical Layer) and simply repeats incoming signals to all ports.
Transceiver: Also operates at Layer 1, converting electrical signals to optical signals and vice versa.
Modem: Primarily operates at Layer 1 and Layer 2, modulating and demodulating signals for
transmission over different types of media.
Practical Application:
Multilayer switches are commonly used in enterprise networks to optimize performance and manage complex routing and switching requirements within a single device.
Reference: CompTIA Network+ study materials on network devices and the OSI model.
A network analyst is installing a wireless network in a corporate environment. Employees are required to use their domain identities and credentials to authenticate and connect to the WLAN.
Which of the following actions should the analyst perform on the AP to fulfill the requirements?
- A . Enable MAC security.
- B . Generate a PSK for each user.
- C . Implement WPS.
- D . Set up WPA3 protocol.
D
Explanation:
WPA3-Enterprise provides strong security and supports authentication using domain identities through a RADIUS server and 802.1X authentication. This is the best choice for a corporate environment requiring user-based authentication.
WPA3-Enterprise Benefits:
Uses 802.1X with EAP (Extensible Authentication Protocol) to authenticate users via a directory service (e.g., Active Directory).
Eliminates shared passwords (PSK) for authentication.
Provides strong encryption and resistance to brute-force attacks.
Incorrect Options:
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
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.
Which of the following is the best networking appliance for interconnecting multiple logical networks and forwarding data packets between them while minimizing latency?
- A . Firewall
- B . Router
- C . Layer 2 switch
- D . Load balancer
B
Explanation:
The correct appliance is a router, which is specifically designed to interconnect multiple networks and forward packets based on IP addresses. Routers operate at Layer 3 (Network layer) of the OSI model and make intelligent forwarding decisions to ensure data reaches the correct destination network.
A technician is troubleshooting a computer issue for a user who works in a new annex of an office building. The user is reporting slow speeds and intermittent connectivity. The computer is connected via a Cat 6 cable to a distribution switch that is 492ft (150m) away.
Which of the following should the technician implement to correct the issue?
- A . Increase the bandwidth allocation to the computer.
- B . Install an access switch in the annex and run fiber to the distribution switch.
- C . Run a Cat 7 cable from the computer to the distribution switch.
- D . Enable the computer to support jumbo frames.
B
Explanation:
The maximum recommended length for Ethernet cable runs is 100 meters (328 feet). At 150 meters, the Cat 6 cable is too long, causing signal degradation and connectivity issues. Running fiber from the distribution switch to an access switch in the annex will allow for reliable connectivity over longer distances, as fiber can cover greater distances without signal loss. (Reference: CompTIA Network+ Study Guide, Chapter on Network Cable Standards)
A network engineer configures the network settings in a new server as follows:
IP address = 192.163.1.15
Subnet mask = 255.255.255.0
Gateway = 192.163.1.255
The server can reach other hosts on the same subnet successfully, but it cannot reach hosts on different subnets.
Which of the following is most likely configured incorrectly?
- A . Subnet mask
- B . Gateway
- C . Default route
- D . IP address
B
Explanation:
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