N10-009 Networking Concepts Practice Test 4 — 15 Questions

Question 1

At which layer of the OSI model does a device provide flow control, error detection, and recovery for end-to-end communication?

Accepted Answer

A: Transport layer. The Transport layer (Layer 4) is responsible for end-to-end communication between source and destination hosts. It provides flow control (e.g., TCP's sliding window mechanism), error detection (via checksums in TCP and UDP headers), and recovery (through TCP retransmission of lost segments). These functions ensure reliable data delivery across the network, distinguishing it from lower layers that handle hop-by-hop or link-local tasks.

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B: Network layer

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C: Data Link layer

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D: Session layer

Question 2

Which of the following network protocols operates at the Transport layer of the OSI model and provides connection-oriented, reliable data delivery?

Accepted Answer

TCP. TCP (Transmission Control Protocol) operates at the Transport layer (Layer 4) of the OSI model and provides connection-oriented, reliable data delivery through mechanisms such as three-way handshake, sequence numbers, acknowledgments, and retransmission of lost segments. This ensures that data is delivered in order and without errors, making TCP the correct choice for the question.

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UDP

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IP

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ARP

Question 3

An IPv6 address has the prefix 2001:db8::/32. Which of the following IP addresses belongs to the same prefix?

Accepted Answer

2001:db8:1::1. The prefix 2001:db8::/32 means the first 32 bits of the address must be 2001:0db8. Option A (2001:db8:1::1) expands to 2001:0db8:0001:0000:0000:0000:0000:0001, which matches the first 32 bits exactly, so it belongs to the same /32 prefix.

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2001:db9::1

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2001:db7::1

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fe80::1

Question 4

Which of the following describes a unicast transmission?

Accepted Answer

One-to-one communication. Unicast transmission is defined as one-to-one communication where a single source sends data to a single destination. In IPv4 networking, this is the standard method for most client-server interactions, such as a host sending an HTTP request to a web server. The destination MAC address in the Ethernet frame is the unique address of the target device, ensuring only that device processes the frame.

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One-to-many communication

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One-to-all communication

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Many-to-many communication

Question 5

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

Accepted Answer

fe80::1. Link-local addresses in IPv6 always start with the prefix fe80::/10, and fe80::1 is a valid example. These addresses are automatically configured on interfaces for local link communication and are not routable beyond the local network segment.

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2001:db8::1

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ff02::1

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10.0.0.1

Question 6

Which of the following describes the purpose of a default gateway on a host in a TCP/IP network?

Accepted Answer

It forwards traffic from the local network to other networks. 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 network. When a host determines that the destination IP is not in its local subnet (via its subnet mask), it forwards the frame to the default gateway's MAC address, which then routes the packet toward the remote network. Without a default gateway, a host can only communicate with devices on the same local broadcast domain.

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It translates domain names to IP addresses

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It assigns IP addresses to devices on the network

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It filters traffic to prevent unauthorized access

Question 7

A network technician is explaining the function of a default gateway to a junior technician. Which of the following best describes the purpose of a default gateway?

Accepted Answer

It routes traffic from the local network to external networks.. The default gateway is a router or Layer 3 device that serves as the next-hop destination for packets destined to IP addresses outside the local subnet. When a host determines that the destination IP is not on the same network, it forwards the frame to the default gateway's MAC address, which then routes the packet toward the external network. This is defined in RFC 1122 and is essential for any host that needs to communicate beyond its directly connected segment.

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It connects two different VLANs.

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It provides DHCP services to the local network.

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It translates private IP addresses to public IP addresses.

Question 8

In the OSI model, which layer is responsible for establishing, managing, and terminating sessions between applications, as well as providing checkpoints and recovery?

Accepted Answer

Session layer. The Session layer (Layer 5) of the OSI model is explicitly responsible for establishing, managing, and terminating sessions between applications, as well as providing checkpointing and recovery mechanisms. This layer uses protocols like NetBIOS, RPC, and PPTP to coordinate dialog control, synchronization points, and session restoration after failures, ensuring that long-lived transactions can resume from a checkpoint rather than restarting entirely.

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Transport layer

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Network layer

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Data link layer

Question 9

A network administrator is configuring IP addresses for a new subnet. The network address is 192.168.1.0 with a subnet mask of 255.255.255.240. How many usable host addresses are available on this subnet?

Accepted Answer

14. The subnet mask 255.255.255.240 (or /28) provides 16 total addresses per subnet. The network address (192.168.1.0) and the broadcast address (192.168.1.15) are reserved, leaving 16 - 2 = 14 usable host addresses. This is calculated as 2^(32-28) - 2 = 2^4 - 2 = 16 - 2 = 14.

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16

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30

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62

Question 10

A network technician is explaining the role of a network switch to a new employee. Which of the following best describes the primary function of a switch in a local area network?

Accepted Answer

It forwards data based on MAC addresses.. A network switch operates at Layer 2 of the OSI model and uses MAC addresses to make forwarding decisions. When a frame arrives, the switch examines the destination MAC address, looks it up in its MAC address table, and forwards the frame only to the port associated with that address, reducing collision domains and improving network efficiency.

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It forwards data based on IP addresses.

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It connects different networks and performs routing.

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It amplifies and repeats the signal to all ports.

Question 11

A network engineer is reviewing RFC 1918 address ranges to plan a private IP addressing scheme. Which of the following IP addresses falls within the private address space for Class A?

Accepted Answer

10.10.10.1. RFC 1918 defines the Class A private address range as 10.0.0.0/8, which includes all addresses from 10.0.0.0 to 10.255.255.255. 10.10.10.1 falls within this range, making it a valid private IP address for internal network use.

Answer

172.16.0.1

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192.168.1.1

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172.32.0.1

Question 12

An engineer is configuring a network and needs to understand the default behavior of an IPv6 node. When an IPv6 interface is initialized, which type of address is automatically assigned without any configuration server?

Accepted Answer

Link-local address. When an IPv6 interface is initialized, it automatically generates a link-local address (fe80::/10) using Stateless Address Autoconfiguration (SLAAC) without requiring any external server (e.g., DHCPv6). This address is mandatory for neighbor discovery and other link-local communication, allowing the node to operate on the local network segment immediately.

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Global unicast address

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Unique local address

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Multicast address

Question 13

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

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ff02::1

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2000::/3

Question 14

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.

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Application layer

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Presentation layer

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Session layer

Question 15

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.

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It provides connectionless communication with minimal overhead.

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It supports multicast and broadcast transmissions.

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