200-901 Network Fundamentals Practice Test 5 — 15 Questions

Question 1

At which layer of the OSI model do MAC addresses operate?

Accepted Answer

Layer 2 – Data Link. MAC addresses operate at Layer 2 (Data Link) of the OSI model because they are used for local network addressing and frame delivery between directly connected devices. The Data Link layer encapsulates packets into frames and uses MAC addresses to identify source and destination interfaces on the same network segment, as defined by IEEE 802 standards.

Answer

Layer 1 – Physical

Answer

Layer 4 – Transport

Answer

Layer 3 – Network

Question 2

Which transport layer protocol is used by HTTP and guarantees reliable delivery?

Accepted Answer

TCP. HTTP relies on TCP (Transmission Control Protocol) as its transport layer protocol because TCP provides reliable, connection-oriented data delivery. TCP ensures that all HTTP requests and responses are delivered in order, without loss or duplication, by using acknowledgments, retransmissions, and sequence numbers. This reliability is essential for HTTP, which expects complete and correct data transfer for web pages and resources.

Answer

ICMP

Answer

IP

Answer

UDP

Question 3

A network administrator is configuring a new subnet for a branch office that requires at least 50 usable host addresses. Which subnet mask would meet this requirement while minimizing address waste?

Accepted Answer

255.255.255.192 (/26). A /26 subnet provides 62 usable hosts (2^6 - 2 = 62), which is the smallest subnet meeting the requirement of 50 hosts.

Answer

255.255.255.0 (/24)

Answer

255.255.255.128 (/25)

Answer

255.255.255.224 (/27)

Question 4

In the TCP three-way handshake, which sequence of flags is exchanged to establish a connection?

Accepted Answer

SYN, SYN-ACK, ACK. The TCP three-way handshake consists of SYN, SYN-ACK, ACK.

Answer

SYN, ACK, SYN-ACK

Answer

ACK, SYN, SYN-ACK

Answer

SYN-ACK, SYN, ACK

Question 5

Which DNS record type is used to map a domain name to an IPv6 address?

Accepted Answer

AAAA. The AAAA record is used for IPv6 address mapping.

Answer

CNAME

Answer

MX

Answer

A

Question 6

An engineer is troubleshooting a VoIP call quality issue. The call uses UDP and experiences packet loss. Which characteristic of UDP most likely contributes to the problem?

Accepted Answer

No retransmission of lost packets. UDP is a connectionless transport protocol that does not provide retransmission of lost packets. In VoIP, packet loss directly degrades call quality because lost audio data is never resent, leading to gaps or distortion in the conversation.

Answer

Ordered delivery guarantee

Answer

Connection-oriented setup

Answer

Flow control mechanism

Question 7

Which of the following is a private IPv4 address range as defined by RFC 1918?

Accepted Answer

172.16.0.0/12. RFC 1918 defines the private IPv4 address range 172.16.0.0/12, which includes addresses from 172.16.0.0 to 172.31.255.255. These addresses are reserved for use within private networks and are not routable on the public internet.

Answer

192.167.0.0/16

Answer

11.0.0.0/8

Answer

172.32.0.0/12

Question 8

In an SDN architecture, which API is used by the controller to communicate with network devices to install forwarding rules?

Accepted Answer

Southbound API. In SDN, the southbound API is the interface between the controller and the network devices (switches, routers). It allows the controller to install forwarding rules, such as flow entries in OpenFlow switches, enabling centralized control of the data plane.

Answer

REST API

Answer

East-West API

Answer

Northbound API

Question 9

An HTTP/2 connection uses multiple concurrent streams over a single TCP connection. Which feature of HTTP/2 enables this?

Accepted Answer

Multiplexing. Multiplexing is the HTTP/2 feature that allows multiple concurrent streams to share a single TCP connection. This eliminates head-of-line blocking at the application layer by enabling the interleaving of frames from different streams, so a slow response on one stream does not block others.

Answer

Binary framing layer

Answer

Server push

Answer

Header compression (HPACK)

Question 10

In a wireless network using 802.11ac, which frequency band does the standard primarily operate in to achieve higher throughput?

Accepted Answer

5 GHz. 802.11ac (Wi-Fi 5) operates exclusively in the 5 GHz band, allowing wider channels and higher throughput.

Answer

2.4 GHz

Answer

6 GHz

Answer

Both 2.4 GHz and 5 GHz

Question 11

What is the primary function of a switch in a network?

Accepted Answer

Forward frames based on MAC addresses. Switches operate at Layer 2 and forward frames based on MAC addresses within a LAN.

Answer

Amplify wireless signals

Answer

Forward packets based on IP addresses

Answer

Convert data to electrical signals

Question 12

A developer is writing a script that uses a REST API to configure network devices via NETCONF. Which layer of the SDN architecture does NETCONF belong to?

Accepted Answer

Southbound interface. NETCONF is a network management protocol used to install, manipulate, and delete the configuration of network devices. In the SDN architecture, the southbound interface is the layer that connects the control plane to the data plane, and NETCONF operates as a southbound protocol by carrying configuration data from a controller or management system down to network devices.

Answer

Northbound interface

Answer

Application layer

Answer

Control layer

Question 13

Which wireless security standard provides the strongest encryption and is recommended for enterprise networks as of 2023?

Accepted Answer

WPA3. WPA3 is the latest standard with stronger encryption (SAE) and is recommended for modern networks.

Answer

WEP

Answer

TKIP

Answer

WPA2

Question 14

Which TWO of the following are benefits of using UDP over TCP for real-time applications?

Accepted Answer

Lower latency due to no connection setup. UDP does not require a three-way handshake (SYN, SYN-ACK, ACK) before data transmission, eliminating the connection setup latency inherent in TCP. This makes UDP ideal for real-time applications like VoIP or video streaming where low delay is critical.

Answer

Guaranteed delivery of all packets

Answer

In-order packet delivery

Answer

Congestion control to avoid network overload

Question 15

Which THREE of the following are characteristics of HTTP/2 compared to HTTP/1.1?

Accepted Answer

Header compression using HPACK. HPACK compression reduces header overhead by encoding header fields, which is a key improvement over HTTP/1.1's uncompressed headers. This minimizes latency and bandwidth usage, especially for repeated headers like cookies and user-agent.

Answer

Plaintext headers for debugging

Answer

Requires multiple TCP connections for parallel requests