CompTIA N10-008 Online Practice Questions and Exam Preparation

CompTIA N10-008 Online Questions & Answers

• Question 601:

  A network engineer installed a new fiber uplink for an office and wants to make sure that the link meets throughput requirements. Which of the following tools should the engineer use to verify that the new link is sufficient?

  A. tcpdump
  B. ping
  C. iperf
  D. netstat
  C. iperf

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  Explanation/Reference:

  iperf is a tool that can measure the bandwidth and quality of a network link by generating and transferring TCP or UDP data streams. iperf can report the maximum achievable throughput, packet loss, jitter, and other statistics for a given link. iperf can be used to test both the uplink and downlink performance of a network link by running it on two endpoints and specifying the direction and duration of the test. iperf can help the engineer verify that the new fiber uplink meets the throughput requirements for the office network. tcpdump is a tool that can capture and analyze network traffic by filtering and displaying packets based on various criteria. tcpdump can help the engineer troubleshoot network problems, monitor network activity, and inspect packet contents, but it cannot measure the throughput or quality of a network link. ping is a tool that can test the reachability and latency of a network host by sending and receiving ICMP echo packets. ping can help the engineer check if the new fiber uplink is connected and responsive, and how long it takes for packets to travel between the endpoints, but it cannot measure the throughput or quality of a network link. netstat is a tool that can display information about the network connections, routing tables, interfaces, and protocols on a network host. netstat can help the engineer view the status and details of the network connections using the new fiber uplink, but it cannot measure the throughput or quality of a network link.

• Question 602:

  At which of the following OSI model layers would a technician find an IP header?

  A. Layer 1
  B. Layer 2
  C. Layer 3
  D. Layer 4
  C. Layer 3

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  Explanation/Reference:

  The seven layers of the OSI model are:

  Physical layer: responsible for transmitting raw data bits over a physical medium such as a cable.

  Data Link layer: provides error-free transmission of data frames over the physical layer.

  Network layer: responsible for routing and addressing of data packets.

  Transport layer: provides reliable end-to-end communication between applications.

  Session layer: establishes, manages, and terminates communication sessions between applications.

  Presentation layer: formats and encrypts data for network transmission.

  Application layer: provides the interface between the application and the network for communication.

• Question 603:

  A network technician needs to ensure the company's external mail server can pass reverse lookup checks.

  Which of the following records would the technician MOST likely configure? (Choose Correct option and give explanation directly from CompTIA Network+ Study guide or documents)

  A. PTR
  B. AAAA
  C. SPF
  D. CNAME
  A. PTR

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  Explanation/Reference:

  A PTR (Pointer) record is used to map an IP address to a domain name, which is necessary for reverse lookup checks. Reverse lookup checks are performed by external mail servers to verify the identity of the sender of the email. By configuring a PTR record, the network technician can ensure that the company's external mail server can pass these checks. According to the CompTIA Network+ Study Guide, "A PTR record is used to map an IP address to a domain name, and it is often used for email authentication."

• Question 604:

  A security engineer is trying to connect cameras to a 12-port PoE switch, but only eight cameras turn on. Which of the following should the engineer check first?

  A. Ethernet cable type
  B. Voltage
  C. Transceiver compatibility
  D. DHCP addressing
  B. Voltage

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  Explanation/Reference:

  The most likely reason why only eight cameras turn on is that the PoE switch does not have enough power budget to supply all 12 cameras. The engineer should check the voltage and wattage ratings of the PoE switch and the cameras, and make sure they are compatible and sufficient. The Ethernet cable type, transceiver compatibility, and DHCP addressing are less likely to cause this problem, as they would affect the data transmission rather than the power delivery.

• Question 605:

  Users are connected to a switch on an Ethernet interface of a campus router. The service provider is connected to the serial 1 interface on the router. The output of the interfaces is: E1/0: 192.168.8.1/24 S1: 192.168.7.252/30

  After router and device configurations are applied, internet access is not possible. Which of the following is the most likely cause?

  A. The Ethernet interface was configured with an incorrect IP address.
  B. The router was configured with an incorrect loopback address.
  C. The router was configured with an incorrect default gateway.
  D. The serial interface was configured with the incorrect subnet mask.
  D. The serial interface was configured with the incorrect subnet mask.

• Question 606:

  A technician is troubleshooting servers with high CPU usage. While trying to connect, the technician needs to open a port for remote access. Which of the following ports should the technician open?

  A. 443
  B. 3321
  C. 8080
  D. 5900
  D. 5900

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  Explanation/Reference:

  Port 5900 is the default port used by Virtual Network Computing (VNC), a graphical desktop-sharing system that allows remote access to another computer's screen, keyboard and mouse1. VNC is one of the tools that can be used for remote troubleshooting of servers with high CPU usage, as it enables the technician to see the server's desktop and perform actions on it. Port 5900 is also one of the ports listed in the CompTIA Network+ N10-008 exam objectives under the section "1.4 Given a scenario, use appropriate software tools to troubleshoot connectivity issues"2. The other ports are not commonly used for remote access. Port 443 is used for Hypertext Transfer Protocol Secure (HTTPS), a secure version of HTTP that encrypts the communication between a web browser and a web server3. Port 3321 is used for Telepathy Broker Service, a service that provides communication between applications and telephony devices4. Port 8080 is used for HTTP Alternate, an alternative port for HTTP that is often used by web servers for testing or proxy purposes5. References

  1: Port 5900: What Is It Used for and How to Open It for RDP

  2: Network+ (Plus) Certification | CompTIA IT Certifications

  3: [What is HTTPS? - Definition from WhatIs.com]

  4: [Telepathy Broker Service - Port 3321 - TCP/UDP]

  5: [What is Port 8080? Why do some processes use this port?]

• Question 607:

  A company is opening a new building on the other side of its campus. The distance from the closest building to the new building is 1,804ft (550m). The company needs to connect the networking equipment in the new building to the other buildings on the campus without using a repeater. Which of the following transceivers should the company use?

  A. 10GBASE-SW
  B. 10GBASE-LR
  C. 10GBASE-LX4 over multimode fiber
  D. 10GBASE-SR
  B. 10GBASE-LR

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  Explanation/Reference:

  10GBASE-SW (MMF 984ft)

  10GBASE-LR (SMF 6 Miles)

  10GBASE-LX4 over multimode fiber (MMF 984ft)

  10GBASE-SR (MMF 1000 ft)

• Question 608:

  Which of the following fields are negotiated during the three-way-handshake process? (Select three).

  A. Sequence number
  B. MTU
  C. Window size
  D. MSS
  E. TTL
  F. Flags
  G. Acknowledgment number
  H. CRC
  A. Sequence number
  C. Window size
  G. Acknowledgment number

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  Explanation/Reference:

  During the TCP three-way handshake process, the following fields are negotiated:

  A. Sequence number: Initial sequence numbers are established during the handshake to keep track of the segments in the communication. C. Window size: This determines the amount of data that can be sent before receiving an acknowledgment.

  G. Acknowledgment number: This confirms receipt of the data and also indicates the next expected byte. The other options are not negotiated during the three-way handshake:

  B. MTU (Maximum Transmission Unit): This is determined at the network layer and is not negotiated during the handshake.

  D. MSS (Maximum Segment Size): This is communicated during the handshake but not negotiated; it's declared by the sender to inform the receiver of the maximum segment size it can handle.

  E. TTL (Time To Live): This is set in each IP packet to limit its lifespan and is not negotiated during the handshake.

  F. Flags: Specific flags are used during the handshake (SYN and ACK), but they are not "negotiated" per se.

  H. CRC (Cyclic Redundancy Check): This is used for error-checking in frames at the data link layer and is not part of the three-way handshake.

• Question 609:

  A customer called the help desk to report a network issue. The customer recently added a hub between the switch and the router in order to duplicate the traffic flow to a logging device. After adding the hub, all the other network components that were connected to the switch slowed more than expected. Which of the following is the MOST likely cause of the issue?

  A. Duplex mismatch
  B. Flow control failure
  C. STP malfunction
  D. 802.1Q disabled
  A. Duplex mismatch

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  Explanation/Reference:

  A duplex mismatch is a situation where two devices on a network have different duplex settings, such as full-duplex or half-duplex. Full-duplex means that a device can send and receive data simultaneously, while half-duplex means that a device can only send or receive data at a time. A duplex mismatch can cause performance issues, such as collisions, errors, or slow throughput. In this scenario, the customer added a hub between the switch and the router. A hub is a device that operates at half-duplex and broadcasts all traffic to all ports. A switch and a router are devices that operate at full-duplex and forward traffic to specific ports. Therefore, adding a hub between the switch and the router can cause a duplex mismatch and slow down all the other network components that were connected to the switch. References: https://www.comparitech.com/net-admin/hub-vs-switch-vs-router/ https://www.cisco.com/c/en/us/support/docs/lan-switching/ethernet/10561-3.html

• Question 610:

  Staff members notify a network technician that the wireless network is not working as expected and connectivity to wireless devices is intermittent. Some devices connect but then disconnect. The technician reviews the logs on the WAP controller and identifies thousands of connection attempts from unrecognized devices within a short amount of time. Which of the following is the most likely reason for the wireless network connectivity issue?

  A. Wrong SSID
  B. Denial of service
  C. Interference
  D. Poor coverage
  B. Denial of service