200-901 Network Fundamentals Practice Test 6 — 15 Questions

Question 1

At which layer of the OSI model do switches operate when forwarding frames based on MAC addresses?

Accepted Answer

Layer 2 (Data Link). Switches operate at Layer 2 (Data Link layer) because they use MAC addresses to forward frames.

Answer

Layer 1 (Physical)

Answer

Layer 3 (Network)

Answer

Layer 4 (Transport)

Question 2

An application requires reliable, ordered delivery of data with error checking. Which transport protocol should be used, and what is a key characteristic of this protocol?

Accepted Answer

TCP, because it uses a 3-way handshake to establish a connection. TCP (Transmission Control Protocol) is the correct choice because it provides reliable, ordered delivery of data with error checking. Its key characteristic is the 3-way handshake (SYN, SYN-ACK, ACK) used to establish a connection before data transfer, ensuring both endpoints are synchronized and ready for reliable communication.

Answer

TCP, because it has lower overhead than UDP

Answer

UDP, because it is connectionless and low-overhead

Answer

UDP, because it provides flow control

Question 3

Which IP address is a valid host address in the 192.168.1.0/24 network?

Accepted Answer

192.168.1.128. /24 means subnet mask 255.255.255.0. Network address is 192.168.1.0, broadcast is 192.168.1.255. Usable hosts range from .1 to .254.

Answer

192.168.2.1

Answer

192.168.1.255

Answer

192.168.1.0

Question 4

A network engineer is designing a subnetting scheme for a company that requires 5 subnets from the 192.168.1.0/24 network. What subnet mask should be used, and how many usable hosts per subnet will be available?

Accepted Answer

255.255.255.224 with 30 usable hosts per subnet. To create 5 subnets, at least 3 bits are needed (2^3=8 subnets). /27 (255.255.255.224) gives 8 subnets with 30 usable hosts each (2^5-2=30).

Answer

255.255.255.192 with 62 usable hosts per subnet

Answer

255.255.255.240 with 14 usable hosts per subnet

Answer

255.255.255.248 with 6 usable hosts per subnet

Question 5

Which DNS record type is used to verify domain ownership for email security (SPF) and is stored as a text string?

Accepted Answer

TXT record. TXT records store arbitrary text, commonly used for SPF, DKIM, and domain verification.

Answer

CNAME record

Answer

A record

Answer

MX record

Question 6

Which wireless standard is commonly known as Wi-Fi 6 and operates in both 2.4 GHz and 5 GHz bands?

Accepted Answer

802.11ax. 802.11ax, marketed as Wi-Fi 6, is the correct answer because it is the only standard among the options that operates in both the 2.4 GHz and 5 GHz bands and introduces OFDMA, 1024-QAM, and improved MU-MIMO for higher efficiency and throughput. Wi-Fi 6 is backward compatible with previous standards but requires compatible clients to leverage its full capabilities.

Answer

802.11g

Answer

802.11n

Answer

802.11ac

Question 7

In an SDN architecture, which layer is responsible for making decisions about where traffic should be forwarded?

Accepted Answer

Control plane. In SDN architecture, the control plane is responsible for making forwarding decisions by maintaining the network topology and computing paths for traffic flows. It communicates these decisions to the data plane via southbound protocols like OpenFlow or NETCONF, ensuring that packets are forwarded according to the desired policies.

Answer

Data plane

Answer

Application plane

Answer

Management plane

Question 8

A network engineer configures an HTTP/2 server. Which feature of HTTP/2 reduces overhead by compressing headers using HPACK?

Accepted Answer

HPACK. HPACK is the header compression mechanism specified for HTTP/2 (RFC 7541). It reduces overhead by encoding HTTP headers into a compact binary format using static and dynamic tables, eliminating redundant header data across requests. This directly addresses the question's focus on reducing overhead through header compression.

Answer

Server push

Answer

Binary framing layer

Answer

Multiplexed streams

Question 9

Which non-overlapping channels are available in the 2.4 GHz band for Wi-Fi to minimize interference?

Accepted Answer

1, 6, 11. Channels 1, 6, and 11 are the only non-overlapping channels in 2.4 GHz.

Answer

1, 3, 5, 7, 9, 11

Answer

1, 5, 9, 13

Answer

2, 7, 12

Question 10

A developer is creating a REST API client that needs to authenticate using credentials passed in the HTTP header. Which header should be used?

Accepted Answer

Authorization. The Authorization header is the standard HTTP header used to transmit credentials (such as Basic, Bearer, or Digest tokens) to authenticate a REST API client. RFC 7235 defines this header as the mechanism for carrying authentication information from the client to the server, making it the correct choice for passing credentials in the HTTP header.

Answer

Host

Answer

Content-Type

Answer

Cookie

Question 11

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

Accepted Answer

10.0.0.0/8. (10.0.0.0/8) is correct because RFC 1918 reserves this range, along with 172.16.0.0/12 and 192.168.0.0/16, for private IPv4 addressing. These addresses are not routable on the public internet and are intended for use within private networks, such as corporate LANs or home networks.

Answer

169.254.0.0/16

Answer

192.167.0.0/16

Answer

172.32.0.0/16

Question 12

In the OSI model, which layer is responsible for session management, including establishing, maintaining, and terminating connections between applications?

Accepted Answer

Layer 5 (Session). The Session layer (Layer 5) manages sessions between applications. The Transport layer handles end-to-end communication.

Answer

Layer 4 (Transport)

Answer

Layer 7 (Application)

Answer

Layer 6 (Presentation)

Question 13

A network administrator is configuring a DNS server. Which TWO DNS record types are used for IPv6 address resolution?

Accepted Answer

PTR record. The AAAA record (option D) maps a hostname to a 128-bit IPv6 address, analogous to the A record for IPv4. The PTR record (option C) performs reverse DNS lookup, mapping an IPv6 address to a hostname, which is essential for IPv6 address resolution in scenarios like logging or mail server verification.

Answer

MX record

Answer

CNAME record

Answer

A record

Question 14

Which THREE of the following are characteristics of the UDP protocol?

Accepted Answer

Used by DNS and DHCP. UDP is a connectionless transport layer protocol that provides minimal overhead, making it ideal for applications like DNS and DHCP that require fast, lightweight communication. DNS uses UDP for queries (port 53) and DHCP uses UDP for client-server exchanges (ports 67/68) because they can tolerate occasional packet loss and benefit from the reduced latency.

Answer

Connection-oriented

Answer

Reliable delivery

Question 15

An engineer is troubleshooting a network issue where a client cannot reach a server. The client uses HTTPS. Which TWO factors are essential for a successful TLS handshake?

Accepted Answer

The server must have a valid digital certificate. The server must present a valid digital certificate during the TLS handshake to prove its identity to the client. This certificate contains the server's public key and is signed by a trusted Certificate Authority (CA), enabling the client to verify the server's authenticity before proceeding with encrypted communication.

Answer

The handshake uses UDP for faster negotiation

Answer

The client must present a certificate to the server

Answer

The client must have a public key to encrypt the session