Practice Free N10-009 Exam Online Questions
Question #121
Which of the following IP transmission types encrypts all of the transmitted data?
- A . ESP
- B . AH
- C . GRE
- D . UDP
- E . TCP
Correct Answer: A
A
Explanation:
Definition of ESP (Encapsulating Security Payload):
ESP is a part of the IPsec protocol suite used to provide confidentiality, integrity, and authenticity of data. ESP encrypts the payload and optional ESP trailer, providing data confidentiality.
ESP Functionality:
ESP can encrypt the entire IP packet, ensuring that the data within the packet is secure from interception or eavesdropping. It also provides options for data integrity and authentication.
ESP operates in two modes: transport mode (encrypts only the payload of the IP packet) and tunnel mode (encrypts the entire IP packet).
Comparison with Other Protocols:
AH (Authentication Header): Provides data integrity and authentication but does not encrypt the payload.
GRE (Generic Routing Encapsulation): A tunneling protocol that does not provide encryption.
UDP (User Datagram Protocol) and TCP (Transmission Control Protocol): These are transport layer protocols that do not inherently provide encryption. Encryption must be provided by additional protocols like TLS/SSL.
Use Cases:
ESP is widely used in VPNs (Virtual Private Networks) to ensure secure communication over untrusted networks like the internet.
Reference: CompTIA Network+ study materials on IPsec and encryption.
A
Explanation:
Definition of ESP (Encapsulating Security Payload):
ESP is a part of the IPsec protocol suite used to provide confidentiality, integrity, and authenticity of data. ESP encrypts the payload and optional ESP trailer, providing data confidentiality.
ESP Functionality:
ESP can encrypt the entire IP packet, ensuring that the data within the packet is secure from interception or eavesdropping. It also provides options for data integrity and authentication.
ESP operates in two modes: transport mode (encrypts only the payload of the IP packet) and tunnel mode (encrypts the entire IP packet).
Comparison with Other Protocols:
AH (Authentication Header): Provides data integrity and authentication but does not encrypt the payload.
GRE (Generic Routing Encapsulation): A tunneling protocol that does not provide encryption.
UDP (User Datagram Protocol) and TCP (Transmission Control Protocol): These are transport layer protocols that do not inherently provide encryption. Encryption must be provided by additional protocols like TLS/SSL.
Use Cases:
ESP is widely used in VPNs (Virtual Private Networks) to ensure secure communication over untrusted networks like the internet.
Reference: CompTIA Network+ study materials on IPsec and encryption.
Question #122
A user cannot access an external server for a client after connecting to a VPN.
Which of the following commands would a support agent most likely use to examine the issue? (Select two).
- A . nslookup
- B . tcpdump
- C . arp
- D . dig
- E . tracert
- F . route print
Correct Answer: E,F
E,F
Explanation:
When a user connects to a VPN and experiences connectivity issues to an external server, the problem is often related to routing or network path issues.
E. tracert:
Traces the path packets take from the user’s device to the destination server.
Helps determine if the traffic is being blocked or misrouted.
F. route print:
Displays the device’s routing table.
Helps diagnose whether traffic is being sent to the VPN tunnel instead of the correct external server.
Incorrect Options:
E,F
Explanation:
When a user connects to a VPN and experiences connectivity issues to an external server, the problem is often related to routing or network path issues.
E. tracert:
Traces the path packets take from the user’s device to the destination server.
Helps determine if the traffic is being blocked or misrouted.
F. route print:
Displays the device’s routing table.
Helps diagnose whether traffic is being sent to the VPN tunnel instead of the correct external server.
Incorrect Options:
Question #123
An employee has a new laptop and reports slow performance when using the wireless network. Switch firmware was updated the previous night.
A network administrator logs in to the switch and sees the following statistics on the switch interface for that employee:
98469 packets input, 1681937 bytes, 0 no buffer
Received 1548 broadcasts (25285 multicasts)
65335 runts, 0 giants, 0 throttles
11546 input errors, 5 CRC, 0 frame, 0 overrun, 0 ignored
0 input packets with dribble condition detected
22781 packets output, 858040 bytes, 0 underruns
0 output errors, 89920 collisions, 0 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier
0 output buffer failures, 0 output buffers swapped out
Which of the following is most likely the cause of the issue?
- A . The patch cord from the wall jack is faulty.
- B . The switchport bandwidth needs to be increased.
- C . Multicast is not configured correctly on the switch.
- D . The NIC is set to half duplex.
Correct Answer: D
D
Explanation:
A large number of collisions and input errors typically indicates a duplex mismatch, such as when one device is set to full duplex and the other to half duplex. This leads to communication issues and poor performance.
The document explains:
“Collisions and input errors are clear signs of duplex mismatches… typically caused when one device operates in half duplex while the other is in full duplex, causing performance and connectivity issues.”
D
Explanation:
A large number of collisions and input errors typically indicates a duplex mismatch, such as when one device is set to full duplex and the other to half duplex. This leads to communication issues and poor performance.
The document explains:
“Collisions and input errors are clear signs of duplex mismatches… typically caused when one device operates in half duplex while the other is in full duplex, causing performance and connectivity issues.”
Question #124
A network engineer performed a migration to a new mail server. The engineer changed the MX record, verified the change was accurate, and confirmed the new mail server was reachable via the IP address in the A record. However, users are not receiving email.
Which of the following should the engineer have done to prevent the issue from occurring?
- A . Change the email client configuration to match the MX record.
- B . Reduce the TTL record prior to the MX record change.
- C . Perform a DNS zone transfer prior to the MX record change.
- D . Update the NS record to reflect the IP address change.
Correct Answer: B
B
Explanation:
Understanding TTL (Time to Live):
TTL is a value in a DNS record that tells how long that record should be cached by DNS servers and clients. A higher TTL value means that the record will be cached longer, reducing the load on the DNS server but delaying the propagation of changes.
Impact of TTL on DNS Changes:
When an MX record change is made, it may take time for the change to propagate across all DNS servers due to the TTL setting. If the TTL is high, old DNS information might still be cached, leading to email being directed to the old server.
Best Practice Before Making DNS Changes:
To ensure that changes to DNS records propagate quickly, it is recommended to reduce the TTL value to a lower value (such as 300 seconds or 5 minutes) well in advance of making the changes. This ensures that any cached records will expire quickly, and the new records will be used sooner.
Verification of DNS Changes:
After reducing the TTL and making the change to the MX record, it is important to verify the propagation using tools like dig or nslookup.
Comparison with Other Options:
Change the email client configuration to match the MX record: Email clients generally do not need to match the MX record directly; they usually connect to a specific mail server specified in their settings.
Perform a DNS zone transfer prior to the MX record change: DNS zone transfers are used to replicate DNS records between DNS servers, but they are not related to the propagation of individual record changes.
Update the NS record to reflect the IP address change: NS records specify the DNS servers for a domain and are not related to MX record changes.
Reference: CompTIA Network+ study materials and DNS best practices.
B
Explanation:
Understanding TTL (Time to Live):
TTL is a value in a DNS record that tells how long that record should be cached by DNS servers and clients. A higher TTL value means that the record will be cached longer, reducing the load on the DNS server but delaying the propagation of changes.
Impact of TTL on DNS Changes:
When an MX record change is made, it may take time for the change to propagate across all DNS servers due to the TTL setting. If the TTL is high, old DNS information might still be cached, leading to email being directed to the old server.
Best Practice Before Making DNS Changes:
To ensure that changes to DNS records propagate quickly, it is recommended to reduce the TTL value to a lower value (such as 300 seconds or 5 minutes) well in advance of making the changes. This ensures that any cached records will expire quickly, and the new records will be used sooner.
Verification of DNS Changes:
After reducing the TTL and making the change to the MX record, it is important to verify the propagation using tools like dig or nslookup.
Comparison with Other Options:
Change the email client configuration to match the MX record: Email clients generally do not need to match the MX record directly; they usually connect to a specific mail server specified in their settings.
Perform a DNS zone transfer prior to the MX record change: DNS zone transfers are used to replicate DNS records between DNS servers, but they are not related to the propagation of individual record changes.
Update the NS record to reflect the IP address change: NS records specify the DNS servers for a domain and are not related to MX record changes.
Reference: CompTIA Network+ study materials and DNS best practices.
Question #125
Which of the following is used to redistribute traffic between one source and multiple servers that run the same service?
- A . Router
- B . Switch
- C . Firewall
- D . Load balancer
Correct Answer: D
D
Explanation:
The correct answer is Load balancer because it is specifically designed to distribute incoming network traffic across multiple backend servers that provide the same application or service. According to CompTIA Network+ (N10-009) objectives under network infrastructure, load balancing improves performance, scalability, and high availability by preventing any single server from becoming overwhelmed.
A load balancer can operate at Layer 4 (transport layer, based on IP address and port) or Layer 7 (application layer, based on content such as HTTP headers or URLs). It uses various algorithms such as round-robin, least connections, or weighted distribution to efficiently allocate client requests among servers. If one server fails, the load balancer can redirect traffic to healthy servers, ensuring service continuity.
A router (Option A) forwards packets between different networks but does not distribute traffic among servers running the same application. A switch (Option B) forwards frames within a local network based on MAC addresses. A firewall (Option C) filters traffic based on security rules but does not perform traffic distribution for load-sharing purposes.
Therefore, a load balancer is the correct solution for redistributing traffic among multiple servers.
D
Explanation:
The correct answer is Load balancer because it is specifically designed to distribute incoming network traffic across multiple backend servers that provide the same application or service. According to CompTIA Network+ (N10-009) objectives under network infrastructure, load balancing improves performance, scalability, and high availability by preventing any single server from becoming overwhelmed.
A load balancer can operate at Layer 4 (transport layer, based on IP address and port) or Layer 7 (application layer, based on content such as HTTP headers or URLs). It uses various algorithms such as round-robin, least connections, or weighted distribution to efficiently allocate client requests among servers. If one server fails, the load balancer can redirect traffic to healthy servers, ensuring service continuity.
A router (Option A) forwards packets between different networks but does not distribute traffic among servers running the same application. A switch (Option B) forwards frames within a local network based on MAC addresses. A firewall (Option C) filters traffic based on security rules but does not perform traffic distribution for load-sharing purposes.
Therefore, a load balancer is the correct solution for redistributing traffic among multiple servers.
Question #126
Which of the following typically uses compromised systems that become part of a bot network?
- A . Evil twin attack
- B . DDoS attack
- C . XML injection
- D . Brute-force password attack
Correct Answer: B
B
Explanation:
A DDoS (Distributed Denial of Service) attack is often launched from botnets ― networks of compromised systems (bots or zombies) under the control of an attacker. These devices flood the target with traffic to disrupt services.
B
Explanation:
A DDoS (Distributed Denial of Service) attack is often launched from botnets ― networks of compromised systems (bots or zombies) under the control of an attacker. These devices flood the target with traffic to disrupt services.
Question #127
Users report latency with a SaaS application.
Which of the following should a technician adjust to fix the issue?
- A . Server hardware specifications
- B . Data-at-rest encryption settings
- C . Network bandwidth and utilization
- D . Virtual machine configurations
Correct Answer: C
C
Explanation:
The correct answer is Network bandwidth and utilization because latency issues with a SaaS (Software as a Service) application are most commonly related to network performance constraints, not local server hardware or virtualization settings. According to CompTIA Network+ (N10-009) troubleshooting objectives, technicians should evaluate bandwidth capacity, throughput, congestion, packet loss, and overall utilization when diagnosing performance issues affecting cloud-based applications.
Since SaaS applications are hosted externally by a service provider, the organization typically does not control the underlying server hardware or virtual machine configurations (Options A and D). Therefore, adjusting internal server specifications would not resolve user-side latency.
Option B, data-at-rest encryption, applies to stored data security and does not impact real-time application responsiveness.
High network utilization, insufficient bandwidth, QoS misconfiguration, or WAN congestion can significantly increase latency. Technicians should review network monitoring tools, check interface statistics, analyze traffic patterns, and verify Quality of Service (QoS) policies to ensure SaaS traffic is prioritized appropriately.
Thus, optimizing bandwidth and reducing network congestion is the most appropriate corrective action.
C
Explanation:
The correct answer is Network bandwidth and utilization because latency issues with a SaaS (Software as a Service) application are most commonly related to network performance constraints, not local server hardware or virtualization settings. According to CompTIA Network+ (N10-009) troubleshooting objectives, technicians should evaluate bandwidth capacity, throughput, congestion, packet loss, and overall utilization when diagnosing performance issues affecting cloud-based applications.
Since SaaS applications are hosted externally by a service provider, the organization typically does not control the underlying server hardware or virtual machine configurations (Options A and D). Therefore, adjusting internal server specifications would not resolve user-side latency.
Option B, data-at-rest encryption, applies to stored data security and does not impact real-time application responsiveness.
High network utilization, insufficient bandwidth, QoS misconfiguration, or WAN congestion can significantly increase latency. Technicians should review network monitoring tools, check interface statistics, analyze traffic patterns, and verify Quality of Service (QoS) policies to ensure SaaS traffic is prioritized appropriately.
Thus, optimizing bandwidth and reducing network congestion is the most appropriate corrective action.
Question #128
Which of the following devices can operate in multiple layers of the OSI model?
- A . Hub
- B . Switch
- C . Transceiver
- D . Modem
Correct Answer: B
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.
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.
Question #129
Which of the following connector types would most likely be used to connect to an external antenna?
- A . BNC
- B . ST
- C . LC
- D . MPO
Correct Answer: A
A
Explanation:
BNC connectors are commonly used for coaxial cables, including those connecting to external antennas in Wi-Fi, radio, and surveillance systems.
Breakdown of Options:
A
Explanation:
BNC connectors are commonly used for coaxial cables, including those connecting to external antennas in Wi-Fi, radio, and surveillance systems.
Breakdown of Options:
Question #130
A network administrator suspects users are being sent to malware sites that are posing as legitimate sites. The network administrator investigates and discovers that user workstations are configured with incorrect DNS IP addresses.
Which of the following should the network administrator implement to prevent this from happening again?
- A . Dynamic ARP inspection
- B . Access control lists
- C . DHCP snooping
- D . Port security
Correct Answer: C
C
Explanation:
DHCP snooping is a security feature on network switches that helps to prevent unauthorized (rogue) DHCP servers from assigning IP addresses to clients. By implementing DHCP snooping, the network administrator can restrict DHCP responses to authorized servers only, preventing unauthorized DHCP configurations, such as incorrect DNS IPs, from being assigned to clients. This helps prevent man-in-the-middle attacks where malicious actors misconfigure DNS to redirect users to fraudulent sites. (Reference: CompTIA Network+ Study Guide, Chapter on Network Security)
C
Explanation:
DHCP snooping is a security feature on network switches that helps to prevent unauthorized (rogue) DHCP servers from assigning IP addresses to clients. By implementing DHCP snooping, the network administrator can restrict DHCP responses to authorized servers only, preventing unauthorized DHCP configurations, such as incorrect DNS IPs, from being assigned to clients. This helps prevent man-in-the-middle attacks where malicious actors misconfigure DNS to redirect users to fraudulent sites. (Reference: CompTIA Network+ Study Guide, Chapter on Network Security)