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Networking Protocols Quiz

Total questions: 161

Worksheet time: 1hrs 21mins

Name
Class
Date
1.

Which layer of the OSI model provides services directly to user applications?

a)

Session Layer

b)

Transport Layer

c)

Application Layer

d)

Network Layer

2.

Which of the following is NOT a function of the Application Layer?

a)

Email communication

b)

Routing data

c)

Domain name resolution

d)

Web browsing

3.

Which protocol is used for browsing websites?

a)

FTP

b)

HTTP

c)

SMTP

d)

DNS

4.

The Application Layer protocols communicate with which OSI layer below them?

a)

Session Layer

b)

Network Layer

c)

Transport Layer

d)

Data Link Layer

5.

Which of the following is an application layer protocol?

a)

IP

b)

ARP

c)

ICMP

d)

SMTP

6.

Which layer does DNS operate in?

a)

Network

b)

Application

c)

Transport

d)

Session

7.

The Application Layer in TCP/IP corresponds to which OSI layers?

a)

Application, Presentation, Session

b)

Transport

c)

Network

d)

Data Link

8.

Which of these is not an Application Layer protocol?

a)

HTTP

b)

TCP

c)

FTP

d)

DNS

9.

What kind of addressing does the Application Layer use?

a)

IP addresses

b)

Application-specific identifiers (e.g., domain names)

c)

MAC addresses

d)

Port numbers

10.

Which protocol is used for resolving domain names?

a)

SMTP

b)

FTP

c)

DNS

d)

HTTPS

11.

What port does HTTP use by default?

a)

443

b)

20

c)

80

d)

53

12.

Which method in HTTP is used to retrieve data from a server?

a)

GET

b)

POST

c)

PUT

d)

DELETE

13.

Which protocol ensures secure HTTP communication?

a)

FTP

b)

HTTPS

c)

DNS

d)

TLS

14.

HTTPS is HTTP over which protocol?

a)

SSH

b)

IPsec

c)

TLS

d)

SSLv2

15.

Which port does HTTPS operate on by default?

a)

25

b)

443

c)

21

d)

53

16.

Which HTTP method is used to submit data to a server?

a)

GET

b)

POST

c)

HEAD

d)

CONNECT

17.

HTTP is considered a ______ protocol.

a)

Stateful

b)

Stateless

c)

Secure

d)

Encrypted

18.

Which protocol handles the TLS handshake in HTTPS?

a)

HTTP

b)

TCP

c)

TLS

d)

FTP

19.

Which version introduced multiplexing in HTTP?

a)

HTTP/1.0

b)

HTTP/2

c)

HTTP/1.1

d)

HTTP/3

20.

What does the HTTP status code 404 mean?

a)

OK

b)

Unauthorized

c)

Not Found

d)

Bad Request

21.

Which component of HTTPS provides encryption and data integrity?

a)

HTTP

b)

TLS

c)

DNS

d)

FTP

22.

What is sent in the first step of TLS handshake?

a)

ServerHello

b)

ClientHello

c)

Certificate

d)

Cipher suite

23.

Which part of HTTPS verifies the identity of the server?

a)

Digital Certificate

b)

IP Address

c)

DNS

d)

Port Number

24.

What is the purpose of header compression in HTTP/2?

a)

Reduce latency

b)

Enable streaming

c)

Secure data

d)

Assign ports

25.

What protocol enables real-time communication over HTTP?

a)

FTP

b)

WebSockets

c)

DNS

d)

POP3

26.

Which port does DNS use?

a)

21

b)

53

c)

80

d)

443

27.

Which DNS record maps a domain to an IPv4 address?

a)

MX

b)

A

c)

AAAA

d)

NS

28.

Which record maps to an IPv6 address?

a)

A

b)

AAAA

c)

MX

d)

CNAME

29.

Which DNS record is used for mail server info?

a)

CNAME

b)

MX

c)

A

d)

TXT

30.

What is the first place checked during DNS resolution?

a)

Local DNS cache

b)

Root server

c)

TLD server

d)

Authoritative DNS server

31.

What type of DNS query expects the full answer from a resolver?

a)

Recursive

b)

Iterative

c)

Broadcast

d)

Forwarding

32.

What DNS technology encrypts queries over HTTPS?

a)

DNSSEC

b)

DoH

c)

DNS over TLS

d)

CDNs

33.

Which component maintains the domain's actual IP records?

a)

Recursive Resolver

b)

Root Server

c)

Authoritative DNS Server

d)

TLD Server

34.

What does a CNAME record do?

a)

Maps alias to canonical domain

b)

Stores IP address

c)

Resolves mail server

d)

Points to DNS server

35.

Which DNS record is queried to find the nameservers?

a)

A

b)

MX

c)

NS

d)

PTR

36.

Which port does FTP control connection use?

a)

20

b)

21

c)

25

d)

53

37.

Which mode in FTP initiates both connections from client side?

a)

Active

b)

Passive

c)

Binary

d)

ASCII

38.

Which command logs into an FTP session?

a)

USER

b)

QUIT

c)

LIST

d)

RETR

39.

Which command uploads a file to server in FTP?

a)

RETR

b)

STOR

c)

LIST

d)

QUIT

40.

Which command lists files in FTP?

a)

USER

b)

LIST

c)

STOR

d)

DATA

41.

Which variant of FTP uses SSH for secure transmission?

a)

SFTP

b)

FTPS

c)

FTP

d)

SCP

42.

Which port does FTP data connection use in active mode?

a)

20

b)

21

c)

22

d)

443

43.

Which FTP variant uses TLS for security?

a)

SFTP

b)

FTPS

c)

HTTP

d)

SSH

44.

What is the purpose of the QUIT command in FTP?

a)

Restart session

b)

Upload file

c)

Change directory

d)

Close connection

45.

What is the difference between active and passive FTP?

a)

Command syntax

b)

Who initiates the data connection

c)

Encryption method

d)

Ports used for control

46.

Which protocol is used for sending emails?

a)

IMAP

b)

POP3

c)

SMTP

d)

HTTP

47.

What is the default unencrypted SMTP port?

a)

587

b)

465

c)

25

d)

21

48.

Which command starts an SMTP session?

a)

HELO

b)

MAIL

c)

RCPT

d)

QUIT

49.

Which SMTP command specifies the sender?

a)

MAIL FROM

b)

RCPT TO

c)

DATA

d)

QUIT

50.

Which protocol is commonly used with SMTP for email retrieval?

a)

FTP

b)

HTTP

c)

IMAP

d)

DNS

51.

What is the purpose of RCPT TO command?

a)

Specifies recipient

b)

Starts message

c)

Terminates session

d)

Authenticates client

52.

What happens during the DATA command in SMTP?

a)

Terminates session

b)

Sends the email content

c)

Authenticates sender

d)

Lists folders

53.

Which port is typically used for SMTP with TLS?

a)

465

b)

587

c)

25

d)

443

54.

SMTP is a ______ protocol.

a)

Push

b)

Pull

c)

Secure

d)

Real-time

55.

Which email protocol retrieves emails from server and deletes them locally?

a)

SMTP

b)

POP3

c)

IMAP

d)

FTP

56.

What does TLS stand for?

a)

Transport Layer Security

b)

Transmission Link Standard

c)

Trusted Link Socket

d)

Transparent Layer Server

57.

What does TLS replace?

a)

FTP

b)

SSL

c)

SSH

d)

IPsec

58.

Which TLS version is deprecated?

a)

TLS 1.0

b)

TLS 1.2

c)

TLS 1.3

d)

TLS 1.1

59.

TLS provides which of the following?

a)

Encryption, Integrity, Authentication

b)

Routing

c)

Compression

d)

Caching

60.

Which of these is part of a TLS handshake?

a)

ClientHello

b)

Ping

c)

Post

d)

NS lookup

61.

What is the purpose of a certificate in TLS?

a)

Assign ports

b)

Prove identity

c)

Encrypt data

d)

Resolve DNS

62.

What problem arises from HTTP pipelining that HTTP/2 solves with multiplexing?

a)

Redundant DNS lookups

b)

Head-of-line blocking

c)

Too many TCP connections

d)

Certificate reuse

63.

Which TLS component provides message integrity?

a)

RSA

b)

SHA256

c)

MAC (Message Authentication Code)

d)

IP header

64.

In a real-world scenario, if a browser can access an IP via ping but cannot load the domain in the browser, what is most likely the issue?

a)

HTTP server is down

b)

DNS resolution failure

c)

TLS handshake timeout

d)

FTP misconfiguration

65.

Which command in SMTP marks the beginning of email content transmission?

a)

HELO

b)

DATA

c)

QUIT

d)

RCPT TO

66.

What does the QUIC protocol (used in HTTP/3) eliminate compared to TCP-based HTTP/2?

a)

Head-of-line blocking due to packet loss

b)

Encryption overhead

c)

Need for TCP congestion control

d)

Need for certificates

67.

Which security feature ensures that a browser should only use HTTPS for a domain in future connections?

a)

TLS 1.3

b)

HTTP Strict Transport Security (HSTS)

c)

DNSSEC

d)

Zero-RTT

68.

What's the key benefit of DNS caching at the browser or OS level?

a)

Reduces encryption overhead

b)

Decreases lookup time

c)

Improves certificate validation

d)

Prevents IP spoofing

69.

What is the biggest drawback of traditional DNS from a security standpoint?

a)

Requires TCP

b)

Sends queries in plaintext

c)

Uses complex headers

d)

Cannot support MX records

70.

Which layer of the OSI model handles end-to-end communication between applications?

a)

Session

b)

Network

c)

Transport

d)

Presentation

71.

What is the purpose of port numbers in the transport layer?

a)

To identify sending and receiving applications

b)

To encrypt data

c)

To resolve domain names

d)

To assign MAC addresses

72.

Which transport layer protocol provides reliable, connection-oriented communication?

a)

UDP

b)

TCP

c)

IP

d)

ICMP

73.

Which of the following is NOT a function of the transport layer?

a)

Segmentation and reassembly

b)

Flow control

c)

Port addressing

d)

IP addressing

74.

Which field in the TCP header helps implement flow control?

a)

Sequence Number

b)

Window Size

c)

Flags

d)

Checksum

75.

In which layer are TCP and UDP found?

a)

Network

b)

Session

c)

Transport

d)

Application

76.

Which OSI layer ensures error-free delivery of data segments?

a)

Transport

b)

Data Link

c)

Session

d)

Physical

77.

Which protocol uses less overhead and is suitable for real-time transmission?

a)

UDP

b)

TCP

c)

SMTP

d)

ICMP

78.

Which function is specific to TCP but not UDP?

a)

Multiplexing

b)

Flow control

c)

Port addressing

d)

Header checksum

79.

What is the default size of a TCP header (without options)?

a)

10 bytes

b)

20 bytes

c)

8 bytes

d)

40 bytes

80.

Which of the following describes TCP?

a)

Reliable and connection-oriented

b)

Unreliable and connectionless

c)

Reliable and connectionless

d)

Ordered but unreliable

81.

What is the first step in the TCP 3-way handshake?

a)

ACK

b)

SYN

c)

FIN

d)

RST

82.

Which of the following flags are used in TCP connection establishment?

a)

FIN, ACK

b)

SYN, SYN-ACK, ACK

c)

PSH, URG

d)

FIN, RST, URG

83.

What is the purpose of the TCP 3-way handshake?

a)

To terminate the connection

b)

To establish a reliable connection

c)

To compress headers

d)

To avoid routing loops

84.

What causes retransmission in TCP?

a)

Timeout or duplicate ACKs

b)

Port mismatch

c)

UDP handshake failure

d)

Header checksum

85.

In TCP, a window size of 0 indicates what?

a)

Receiver can't accept data now

b)

Transmission complete

c)

Packet lost

d)

Sender should close connection

86.

TCP sequence numbers are used to:

a)

Encrypt the packet

b)

Ensure ordered delivery

c)

Validate domain names

d)

Address processes

87.

How many steps are involved in TCP connection termination?

a)

2

b)

4

c)

3

d)

1

88.

What flag is set when closing a TCP connection?

a)

URG

b)

FIN

c)

SYN

d)

PSH

89.

TCP congestion control algorithm that starts slow and grows exponentially:

a)

Slow Start

b)

Additive Increase

c)

Fast Recovery

d)

Linear Scaling

90.

Which algorithm kicks in after triple duplicate ACKs in TCP?

a)

Slow Start

b)

Fast Retransmit

c)

Go-Back-N

d)

Checksum

91.

TCP congestion avoidance grows the window size how?

a)

Exponentially

b)

Linearly

c)

Logarithmically

d)

Statically

92.

When TCP detects loss through timeout, it:

a)

Reduces congestion window

b)

Increases window

c)

Sends duplicate ACKs

d)

Ignores

93.

Which value in TCP header helps implement congestion control?

a)

Port number

b)

Congestion Window (cwnd)

c)

Checksum

d)

TTL

94.

If cwnd = 4, and ACKs for all are received, what will cwnd be next in Slow Start?

a)

5

b)

8

c)

6

d)

3

95.

What TCP strategy prevents the sender from flooding the network?

a)

Port blocking

b)

Congestion control

c)

DNS caching

d)

Header compression

96.

TCP Fast Recovery is used after:

a)

FIN

b)

Timeout

c)

Fast Retransmit

d)

Window probe

97.

Flow control operates between:

a)

Sender and receiver

b)

Switch and router

c)

Application and transport

d)

DNS and HTTP

98.

Which congestion control phase occurs after loss detection?

a)

Recovery

b)

Transmission

c)

Initiation

d)

Discovery

99.

Which transport layer protocol does NOT guarantee delivery?

a)

TCP

b)

UDP

c)

ICMP

d)

HTTP

100.

What is the size of the UDP header?

a)

20 bytes

b)

8 bytes

c)

12 bytes

d)

16 bytes

101.

UDP is preferred over TCP in which scenario?

a)

Bank transaction

b)

Video streaming

c)

File upload

d)

Web login

102.

Which of these is NOT a field in the UDP header?

a)

Source Port

b)

Length

c)

Sequence Number

d)

Checksum

103.

Which application typically uses UDP?

a)

SSH

b)

DNS

c)

HTTPS

d)

SFTP

104.

UDP is called connectionless because:

a)

It requires more time to connect

b)

It does not establish handshakes

c)

It uses ICMP

d)

It maintains sessions

105.

Which of the following is true about UDP?

a)

Reliable, but unordered

b)

Secure

c)

Low overhead

d)

Uses congestion control

106.

VoIP applications prefer UDP because:

a)

Speed matters more than reliability

b)

It uses SSL

c)

TCP consumes less power

d)

DNS is not needed

107.

Which of the following uses UDP by default?

a)

TFTP

b)

Telnet

c)

SSH

d)

FTP

108.

UDP is best for applications that:

a)

Need error correction

b)

Send small amounts of reliable data

c)

Tolerate packet loss and require speed

d)

Require sequencing

109.

Which is better for sending a large image file?

a)

TCP

b)

UDP

c)

ICMP

d)

FTP over UDP

110.

YouTube streaming prefers:

a)

TCP

b)

UDP

c)

SMTP

d)

ICMP

111.

A multiplayer game would use:

a)

UDP

b)

TCP

c)

FTP

d)

HTTP

112.

Which protocol is suitable for sending secure login details?

a)

TCP

b)

UDP

c)

FTP

d)

SMTP

113.

In TCP, what does the SYN flag indicate during connection setup?

a)

Data Ready

b)

Start Connection

c)

Disconnect Request

d)

Retransmission

114.

Which TCP congestion control phase increases the congestion window size exponentially?

a)

Fast Recovery

b)

Congestion Avoidance

c)

Slow Start

d)

Retransmit Timeout

115.

A video calling app uses UDP. What drawback might users face compared to TCP-based streaming?

a)

Slower data rate

b)

Higher connection latency

c)

Potential data loss

d)

Enforced encryption

116.

You are asked to design a secure file transfer system for enterprise clients. Which stack would you choose?

a)

UDP + Custom Encryption

b)

FTP over TCP

c)

SFTP (SSH-based)

d)

TFTP

117.

In a system transferring sensor data over a network, data loss is acceptable, but speed is critical. Choose protocol:

a)

TCP

b)

SMTP

c)

UDP

d)

SFTP

118.

A system has to handle burst traffic like software updates to millions of users. Which congestion control strategy is best?

a)

Disable Nagle's Algorithm

b)

Use TCP Slow Start with adaptive threshold

c)

Use constant cwnd

d)

UDP with retry logic

119.

A client sends data with TCP and waits for ACKs. But due to high latency, ACKs are delayed. What happens?

a)

TCP slows down sending rate

b)

TCP retransmits all data

c)

TCP switches to UDP

d)

TCP ignores ACK delay

120.

How does TCP ensure the correctness of received data?

a)

Time synchronization

b)

Port verification

c)

Checksum and sequence numbers

d)

Ping command

121.

What is the primary purpose of the congestion window (cwnd) in TCP?

a)

To limit the number of packets in the receiver's buffer

b)

To limit the sender's rate based on network capacity

c)

To detect corrupted packets

d)

To manage port multiplexing

122.

During TCP slow start, if cwnd starts at 1 MSS, what will it be after 3 successful ACKs (no loss)?

a)

2

b)

4

c)

8

d)

6

123.

Which TCP congestion control algorithm is triggered by 3 duplicate ACKs?

a)

Slow Start

b)

Congestion Avoidance

c)

Fast Retransmit

d)

Exponential Backoff

124.

You observe out-of-order packets and increased retransmissions. What might be a possible cause?

a)

UDP congestion

b)

Switch buffering

c)

Asymmetric routing

d)

Low window size

125.

In TCP, which header field is used for flow control?

a)

Sequence Number

b)

Acknowledgment Number

c)

Window Size

d)

Urgent Pointer

126.

Why is UDP preferred over TCP in real-time applications like VoIP?

a)

Because it is encrypted

b)

Because it supports retransmission

c)

Because delay is more tolerable than loss

d)

Because it has larger headers

127.

Which statement best explains the 'Silly Window Syndrome' in TCP?

a)

It's a type of SYN flooding attack

b)

It occurs when the sender waits too long before sending data

c)

It results from frequent small window updates causing poor throughput

d)

It arises due to misconfigured port numbers

128.

Which condition forces TCP into slow start again?

a)

Triple duplicate ACKs

b)

Zero window advertisement

c)

RTO (Retransmission Timeout)

d)

FIN flag received

129.

In a high-latency, high-bandwidth network, what TCP tuning parameter is most critical?

a)

MTU

b)

Maximum segment size

c)

Window scaling factor

d)

Port number

130.

How does TCP prevent infinite retransmission of the same segment?

a)

Sequence number check

b)

Exponential backoff with timeout

c)

Acknowledgment delay

d)

Port reset

131.

Your application uses TCP and stalls under heavy load. What might be a fix?

a)

Use smaller packet sizes

b)

Switch to UDP

c)

Enable window scaling

d)

Reduce MSS

132.

In a server load test, you observe high RTTs and retransmissions. Which congestion control algorithm may perform better than Reno?

a)

Tahoe

b)

NewReno

c)

CUBIC

d)

AIMD

133.

You are designing a custom file transfer protocol over UDP. What must you implement yourself?

a)

Packet headers

b)

Encryption

c)

Flow and error control

d)

Port numbers

134.

What TCP header field ensures reliable and ordered data delivery?

a)

Sequence Number

b)

Checksum

c)

Window Size

d)

Urgent Flag

135.

Which of the following is true for QUIC compared to TCP?

a)

It works only over port 80

b)

It provides reliable but unordered delivery

c)

It multiplexes streams to reduce head-of-line blocking

d)

It cannot use TLS encryption

136.

What is a computer network?

a)

A group of independent computers connected by wireless media only

b)

A group of computers that operate as standalone systems

c)

A collection of interconnected computing devices sharing resources

d)

A collection of software running in isolation

137.

The main purpose of networking is:

a)

Editing videos

b)

Data transfer and resource sharing

c)

Programming

d)

Installing operating systems

138.

Which of the following is an example of a network application?

a)

Microsoft Word

b)

Adobe Photoshop

c)

File sharing over LAN

d)

Calculator

139.

What is one major advantage of computer networks?

a)

Less power consumption

b)

Increased software usage

c)

Faster individual computation

d)

Resource sharing

140.

Which of the following is NOT a benefit of computer networking?

a)

Resource sharing

b)

High data redundancy

c)

Centralized data management

d)

Backup and recovery

141.

Which protocol is used for email communication?

a)

HTTP

b)

SMTP

c)

FTP

d)

SNMP

142.

Which of these is an application layer protocol?

a)

IP

b)

TCP

c)

DNS

d)

Ethernet

143.

Which of the following is an example of client-server architecture?

a)

Peer-to-peer file sharing

b)

Email server and client

c)

Direct cable connection

d)

USB to serial connection

144.

Which networking device forwards packets based on IP addresses?

a)

Switch

b)

Router

c)

Hub

d)

Modem

145.

Which of these is not typically shared over a network?

a)

Printer

b)

Files

c)

CPU registers

d)

Internet connection

146.

In which configuration does each device have a dedicated point-to-point link to every other device?

a)

Mesh

b)

Star

c)

Ring

d)

Bus

147.

Which line configuration requires the most cabling?

a)

Bus

b)

Ring

c)

Mesh

d)

Star

148.

Which line configuration has a single communication line shared by all devices?

a)

Star

b)

Mesh

c)

Ring

d)

Bus

149.

In star topology, failure of the central hub results in:

a)

Failure of only one node

b)

Full network failure

c)

Continued operation

d)

Failure of outer ring only

150.

Which topology has a token-passing mechanism?

a)

Bus

b)

Star

c)

Ring

d)

Mesh

151.

Which configuration is best for fault tolerance?

a)

Mesh

b)

Bus

c)

Ring

d)

Star

152.

Which configuration is least expensive?

a)

Mesh

b)

Ring

c)

Bus

d)

Star

153.

Line configuration where one device is directly connected to another:

a)

Multipoint

b)

Point-to-point

c)

Ring

d)

Mesh

154.

A multipoint connection allows:

a)

Only two devices

b)

Dedicated channel per device

c)

Multiple devices sharing a link

d)

One-way communication

155.

Which configuration makes troubleshooting easier?

a)

Mesh

b)

Star

c)

Ring

d)

Bus

156.

Which topology connects all devices in a closed loop?

a)

Ring

b)

Star

c)

Mesh

d)

Bus

157.

What topology uses a central hub?

a)

Bus

b)

Star

c)

Ring

d)

Tree

158.

Which topology is most redundant?

a)

Star

b)

Mesh

c)

Bus

d)

Ring

159.

Which topology is easiest to install and cost-effective for small networks?

a)

Bus

b)

Star

c)

Mesh

d)

Ring

160.

Which topology is a hybrid of star and bus topologies?

a)

Tree

b)

Mesh

c)

Ring

d)

Star

161.

Failure of a single cable affects entire network in:

a)

Bus topology

b)

Mesh topology

c)

Tree topology

d)

Star topology