N10-009 Networking Concepts Practice Test 5 — 15 Questions

Question 1

Which of the following best describes the primary function of a subnet mask in IPv4 networking?

Accepted Answer

It identifies which part of an IP address is the network address and which part is the host address. The subnet mask is a 32-bit value that separates the IP address into network and host portions through a bitwise AND operation. This allows routers and hosts to determine whether a destination IP is on the same local network or requires forwarding to a default gateway. Without the subnet mask, a device cannot distinguish the network prefix from the host identifier, making routing impossible.

Answer

It dynamically assigns IP addresses to devices on the network

Answer

It encrypts data packets to ensure secure communication

Answer

It specifies the IP address of the router that forwards traffic to other networks

Question 2

Which of the following IPv6 addresses is a link-local address?

Accepted Answer

fe80::1. (fe80::1) is correct because IPv6 link-local addresses always begin with the prefix fe80::/10, as defined in RFC 4291. These addresses are automatically assigned to every IPv6-enabled interface and are only valid on a single link (subnet), never routed. The address fe80::1 is a common example of a link-local address.

Answer

2001:db8::1

Answer

ff02::1

Answer

2000::/3

Question 3

A network technician is reviewing the OSI model to understand how data is encapsulated when a web request is sent from a client to a server. At which layer does the web browser's HTTP request data get encapsulated with a TCP segment header?

Accepted Answer

Transport layer. The Transport layer (Layer 4) is responsible for encapsulating application data with a TCP or UDP segment header. When a web browser sends an HTTP request, the HTTP data is passed down from the Application layer to the Transport layer, where the TCP segment header (including source/destination ports, sequence numbers, and checksum) is added. This encapsulation occurs at Layer 4, not at any higher layer.

Answer

Application layer

Answer

Presentation layer

Answer

Session layer

Question 4

A network technician is explaining the difference between TCP and UDP to a junior technician. Which of the following correctly identifies a characteristic of TCP but NOT of UDP?

Accepted Answer

It uses a three-way handshake to establish a connection before data transfer.. TCP is a connection-oriented protocol that uses a three-way handshake (SYN, SYN-ACK, ACK) to establish a reliable connection before any data is transmitted, ensuring ordered delivery and error recovery. UDP, in contrast, is connectionless and sends datagrams without any prior setup, making the three-way handshake a defining characteristic of TCP only.

Answer

It provides connectionless communication with minimal overhead.

Answer

It supports multicast and broadcast transmissions.

Answer

It is commonly used for real-time applications like VoIP and video streaming.

Question 5

A network technician is explaining network segmentation to a junior technician. Which of the following devices increases the number of collision domains but does not increase the number of broadcast domains?

Accepted Answer

Switch. A switch creates a separate collision domain for each port, so multiple devices can transmit simultaneously without collisions, but it does not segment broadcast domains; all ports remain in the same broadcast domain unless VLANs are configured. This directly matches the question's requirement: increasing collision domains without increasing broadcast domains.

Answer

Hub

Answer

Router

Answer

Repeater

Question 6

A network technician is explaining the process of resolving Layer 2 addresses to Layer 3 addresses on a local network. Which protocol is used by a host to determine the MAC address of another host given its IP address?

Accepted Answer

ARP. ARP (Address Resolution Protocol) is the correct answer because it is specifically designed to resolve a known Layer 3 (IP) address to an unknown Layer 2 (MAC) address on a local network. When a host needs to send a frame to another host, it first checks its ARP cache; if no entry exists, it broadcasts an ARP request containing the target IP, and the host with that IP responds with its MAC address. This process is defined in RFC 826 and operates at the data link layer, enabling direct communication within the same broadcast domain.

Answer

DNS

Answer

DHCP

Answer

ICMP

Question 7

A network engineer needs to create subnets for four departments, each requiring at least 50 host addresses. The available network is 192.168.1.0/24. Which subnet mask should be used to satisfy the requirements while minimizing wasted addresses?

Accepted Answer

/26 (255.255.255.192). A /26 subnet mask (255.255.255.192) provides 62 usable host addresses per subnet (2^(32-26) - 2 = 62), which meets the requirement of at least 50 hosts per department. With a /24 network, you can create exactly four /26 subnets (192.168.1.0/26, 192.168.1.64/26, 192.168.1.128/26, 192.168.1.192/26), perfectly matching the four departments while minimizing wasted addresses.

Answer

/25 (255.255.255.128)

Answer

/27 (255.255.255.224)

Answer

/24 (255.255.255.0)

Question 8

Which of the following best describes the primary function of the transport layer in the OSI model?

Accepted Answer

Providing end-to-end communication and data flow control. The transport layer (Layer 4) is responsible for end-to-end communication between hosts, including segmentation, reassembly, and flow control. Protocols like TCP use windowing and acknowledgments to manage data flow, ensuring reliable delivery. This distinguishes it from lower layers that handle routing or physical signaling.

Answer

Routing packets across networks

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Encoding data into electrical signals

Answer

Determining the best path for data transmission

Question 9

A network engineer is designing a subnet to accommodate 50 devices in a single broadcast domain. The engineer uses a /26 subnet mask. How many usable host addresses are available?

Accepted Answer

62. A /26 subnet mask provides 2^(32-26) = 64 total addresses. Subtracting the network and broadcast addresses leaves 62 usable host addresses. This is sufficient for 50 devices in a single broadcast domain.

Answer

30

Answer

126

Answer

254

Question 10

A network technician is explaining the difference between connection-oriented and connectionless protocols to a junior technician. Which of the following protocols is connectionless at the transport layer?

Accepted Answer

UDP. UDP (User Datagram Protocol) is the correct answer because it is a connectionless transport-layer protocol. It does not establish a session or guarantee delivery, instead sending datagrams independently without handshaking or acknowledgments, which makes it suitable for real-time applications like VoIP and streaming.

Answer

TCP

Answer

ICMP

Answer

ARP

Question 11

A network engineer is designing a network for a large organization. The engineer needs to ensure that broadcast traffic from one VLAN does not propagate to other VLANs while still allowing inter-VLAN communication. Which of the following devices is required to route between VLANs?

Accepted Answer

Router. A router is required to route between VLANs because VLANs segment a Layer 2 broadcast domain, and inter-VLAN communication must occur at Layer 3. The router performs routing by receiving frames tagged with the source VLAN, stripping the tag, making a forwarding decision based on the destination IP, and then re-encapsulating the frame with the destination VLAN tag. This process is often implemented using a router-on-a-stick configuration with 802.1Q trunking.

Answer

Layer 2 switch

Answer

Bridge

Answer

Firewall

Question 12

Which of the following best describes the purpose of the TCP three-way handshake?

Accepted Answer

To establish a reliable connection between two hosts. The TCP three-way handshake is the process by which two hosts synchronize sequence numbers and establish a reliable connection before data transfer begins. It involves the exchange of SYN, SYN-ACK, and ACK segments, ensuring both sides are ready to communicate and agree on initial sequence numbers (ISNs) as defined in RFC 793.

Answer

To terminate a connection gracefully

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To resolve an IP address to a MAC address

Answer

To encrypt data between two devices

Question 13

Which of the following best describes the function of a default gateway on a host?

Accepted Answer

It forwards packets destined for networks other than the local subnet. The default gateway is the router interface on the local subnet that a host uses to send packets destined for IP addresses outside its own subnet. When a host determines that the destination IP is not reachable via ARP on the local link, it forwards the packet to the default gateway's MAC address, which then routes the packet toward the remote network. This is essential for inter-subnet communication in any IP network.

Answer

It resolves domain names to IP addresses

Answer

It assigns IP addresses to devices on the local network

Answer

It filters traffic based on MAC addresses

Question 14

Which of the following best describes the primary difference between a hub and a switch?

Accepted Answer

A hub broadcasts all frames to all ports; a switch forwards frames only to the destination port. A hub operates at Layer 1 (physical layer) and simply repeats electrical signals out all ports, causing all connected devices to receive every frame. A switch operates at Layer 2 (data link layer) and uses the MAC address table to forward frames only to the specific port where the destination device resides, reducing unnecessary traffic and improving network efficiency.

Answer

A switch is faster than a hub because it operates at Layer 3

Answer

A hub can segment collision domains; a switch cannot

Answer

Both hubs and switches operate at the same OSI layer but use different frame types

Question 15

At which layer of the OSI model does end-to-end communication and data segmentation occur?

Accepted Answer

Transport layer. The transport layer (Layer 4) is responsible for end-to-end communication between source and destination hosts, as well as data segmentation and reassembly. Protocols such as TCP and UDP operate at this layer, with TCP providing reliable, connection-oriented service by segmenting data into segments and managing flow control and error recovery.

Answer

Session layer

Answer

Network layer

Answer

Data link layer