CompTIA N10-009 Online Practice Questions and Exam Preparation

CompTIA N10-009 Online Questions & Answers

• Question 11:

  Which of the following network traffic type is sent to all nodes on the network?

  A. Unicast
  B. Broadcast
  C. Multicast
  D. Anycast
  B. Broadcast

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  Explanation

  Broadcast traffic is sent to all nodes on the network. In a broadcast, a single packet is transmitted to all devices in the network segment. This is commonly used for tasks like ARP (Address Resolution Protocol) requests.

  Broadcast Domain: All devices within the same broadcast domain will receive broadcast traffic.

  Network Types: Ethernet networks commonly use broadcast traffic for certain functions, including network discovery and addressing.

  IPv4 Broadcast: An IPv4 broadcast address (e.g., 255.255.255.255) ensures the packet is sent to all devices on the network.

  References:

  CompTIA Network+ N10-007 Official Certification Guide: Explains network traffic types, including broadcast, unicast, and multicast. Cisco Networking Academy: Provides training on network communication methods and traffic types. Network

  + Certification All-in-One Exam Guide: Discusses different types of network traffic and their uses in various network scenarios. Broadcast traffic is essential for network operations that require communication with all nodes, such as ARP requests or DHCP discovery messages.

• Question 12:

  A network administrator needs to connect a department to a new network segment. They need to use a DHCP server located on another network.

  Which of the following can the administrator use to complete this task?

  A. IP Helper
  B. Reservation
  C. Exclusion
  D. Scope
  A. IP Helper

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  Explanation

  An IP Helper (IP Helper Address) allows DHCP requests to pass through routers and reach a DHCP server on another network.

  1. DHCP broadcasts are not forwarded across routers by default, so an IP Helper Address is needed to relay the request.

  2. This is crucial for large networks where a single DHCP server serves multiple subnets.

  3. Option B (Reservation): Ensures a specific IP address is assigned to a MAC address but does not relay DHCP across networks.

  4. Option C (Exclusion): Prevents specific IP addresses from being assigned, but does not help with DHCP relay.

  5. Option D (Scope): Defines the range of IP addresses available for DHCP clients but does not assist in cross-network communication.

  References:

  CompTIA Network+ (N10-009) Official Study Guide Section: DHCP and IP Addressing

• Question 13:

  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. ping

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  Explanation

  Ping sends ICMP Echo Request packets and waits for Echo Replies to verify host reachability and measure round-trip time.

  Option A: tcpdump captures packets but does not test reachability.

  Option B: netstat displays open ports and network sessions.

  Option C: nslookup queries DNS servers for name resolution.

  References:

  Domain: Networking Concepts -- ICMP operation, troubleshooting tools.

• Question 14:

  A network administrator is looking for a solution to extend Layer 2 capabilities and replicate backups between sites.

  Which of the following is the best solution?

  A. Security Service Edge
  B. Data center interconnect
  C. Infrastructure as code
  D. Zero Trust architecture
  B. Data center interconnect

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  Explanation

  The correct solution is a Data Center Interconnect (DCI). DCIs extend Layer 2 networks across geographically dispersed data centers, enabling seamless replication of services such as SAN storage, backup synchronization, or VM migrations. This ensures workloads and data can move between sites while maintaining the same VLANs and addressing.

  Option A. Security Service Edge (SSE) provides cloud-delivered security functions like secure web gateways and CASB, not Layer 2 extension.

  Option C. Infrastructure as code (IaC) automates deployment and management of network infrastructure but is unrelated to extending Layer 2 domains.

  Option D. Zero Trust architecture is a security framework ensuring strict access control but doesn't address network connectivity between sites.

  In scenarios where backups need replication between sites, Layer 2 extension is often required so systems can communicate as if they are in the same broadcast domain. DCI is specifically designed to provide this functionality reliably and securely.

  References:

  Domain: Network Infrastructure -- WAN technologies, data center interconnect, backup replication.

• Question 15:

  Which of the following types of attacks is most likely to occur after an attacker sets up an evil twin?

  A. On-path
  B. DDoS
  C. ARP spoofing
  D. Phishing
  A. On-path

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  Explanation

  An evil twin is a malicious wireless access point that impersonates a legitimate SSID. Once victims connect, the attacker can intercept and manipulate traffic, performing an on-path (man-in-the-middle) attack-- capturing credentials, injecting content, or downgrading encryption.

  Option B: DDoS overwhelms services with traffic; it's not the typical follow-on from clients joining a rogue AP.

  Option C: ARP spoofing is another way to become on-path on wired segments, but with an evil twin, the wireless association itself enables the on-path position.

  Option D: Phishing is social engineering; while an evil twin could be used to present fake portals, the primary technical posture after connection is on-path.

  References:

  Domain: Network Security -- Wireless threats (rogue APs/evil twins), traffic interception, on-path attacks.

• Question 16:

  Which of the following is used to translate private IP addresses to a public IP address?

  A. DNS
  B. NAT
  C. SNMP
  D. NTP
  B. NAT

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  Explanation

  Network Address Translation (NAT) is used to map private IP addresses to a public IP address, allowing multiple devices within a private network to share a single public IP for internet access. NAT conserves public IP address space and adds a layer of security by hiding internal addressing schemes. DNS resolves domain names, SNMP is used for monitoring, and NTP synchronizes time. NAT is essential for communication between private networks and external networks.

• Question 17:

  A network administrator is deploying a new switch and wants to make sure that the default priority value was set for a spanning tree.

  Which of the following values would the network administrator expect to see?

  A. 4096
  B. 8192
  C. 32768
  D. 36684
  C. 32768

• Question 18:

  A user reports slow network performance. The administrator discovers excessive broadcast traffic.

  Which of the following would reduce this issue?

  A. Implement VLANs
  B. Increase bandwidth
  C. Use a hub
  D. Disable DNS
  A. Implement VLANs

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  Explanation

  Broadcast traffic is limited to a broadcast domain, and excessive broadcasts can degrade network performance. VLANs segment a network into smaller logical broadcast domains, reducing the scope of broadcast traffic. By dividing a large network into multiple VLANs, broadcasts are contained within each VLAN rather than flooding the entire network. Increasing bandwidth does not address broadcast storms, hubs increase broadcast domains, and DNS is unrelated. VLAN implementation is the correct method for controlling broadcast traffic.

• Question 19:

  A network engineer configures a NIC that has an IP address of 192.168.123.232.

  Which of the following classes is this address an example of?

  A. Class A
  B. Class B
  C. Class C
  D. Class D
  C. Class C

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  Explanation

  The IPv4 address 192.168.123.232 falls within the Class C range under classful addressing. In classful terms, Class C addresses have a first octet from 192 to 223, which makes any address starting with 192.x.x.x a Class C address. Network

  + (N10-009) networking concepts cover IPv4 addressing fundamentals and commonly reference class ranges as foundational knowledge, even though modern networks primarily use CIDR (classless) subnetting rather than strict classful boundaries.

  This address is also within a well-known private IPv4 block: 192.168.0.0/16 (RFC1918 private addressing), which is frequently used for internal networks and NIC configurations where addresses are not routable on the public internet.

  To eliminate the distractors: Class A uses first octet 1-126, Class B uses 128-191, and Class D (224-239) is reserved for multicast. Since the first octet here is 192, it maps to Class C, making option C correct.

• Question 20:

  Which of the following routing technologies allows all users to access the internet using only two public IPs?

  A. EIGRP
  B. PAT
  C. BGP
  D. VIP
  B. PAT

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  Explanation

  The correct answer is B. PAT. Port Address Translation allows many internal devices that use private IP addresses to share a small number of public IP addresses when accessing the internet. In this case, the question says all users can access the internet using only two public IPs, which is exactly the kind of situation PAT is designed for. The device performing PAT keeps track of each connection by using source port numbers, so multiple internal sessions can be translated and maintained at the same time without requiring a unique public IP for every user.

  The other options do not match this function. EIGRP and BGP are routing protocols used to exchange routing information, not to translate addresses for outbound internet traffic. VIP refers to a virtual IP address, commonly used in high availability or load-balancing scenarios, but it does not provide the many-to-one address translation behavior described in the question.

  For Network+ exam purposes, when the scenario talks about conserving public IPv4 addresses and allowing many users to reach external networks through a very small number of public IPs, the expected answer is PAT. This is one of the most common real-world uses of NAT technology at the network edge.