2.1 Compare & contrast Transmission Control Protocol (TCP) & User Datagram Protocol (UDP) ports, protocols, & their purpose

Question 1

What protocols in the TCP/IP suite handle port assignment?

Answer 1

TCP & UDP

Question 2

Meaning of UDP?

Answer 2

User Datagram Protocol

Question 3

How many port numbers do hosts assign?

Answer 3

2

Question 4

Explain the port assignment process

Answer 4

Each host assigns a destination & source port

Question 5

In the port assignment process, what does the destination port map to?

Answer 5

The requested service

i.e. HTTP on port 80

Question 6

What is the source port in the port assignment process?

Answer 6

Random port number chosen by the client

i.e. 47747

The server replies using the client’s source port as its destination port & its own app port as the source port

Question 7

How does TCP differ from UDP?

Answer 7

Providing reliable data delivery

Question 8

What is TCP known as?

Answer 8

Connection-oriented protocol

Question 9

How does TCP establish a connection between sender & recipient?

Answer 9

via Handshake sequence

Question 10

List TCP’s handshake sequence packets

Answer 10

• SYN packet
• SYN/ACK packet
• ACK packet

Question 11

What does TCP assign to each packet?

Answer 11

A sequence number

Question 12

Why does TCP assign sequence numbers to packets?

Answer 12

So they can be tracked

Question 13

In TCP, why do clients send ACK packets?

Answer 13

To acknowledge that a packet has been received

Question 14

In TCP, why do clients send NACK packets?

Answer 14

For retransmission of a missing or damaged packet

NACK basically means Negative Acknowledgement

Question 15

Main drawback of TCP?

Answer 15

Connection info increases packet size due to multiple header fields

Question 16

When is TCP used?

Answer 16

When application protocols can’t tolerate missing or damaged info.

Question 17

2 application protocols that must use TCP?

Answer 17

• HTTPS
• SSH

Question 18

What is UDP known as?

Answer 18

Connectionless protocol

Question 19

How does UDP differ from TCP?

Answer 19

Faster & not guaranteeing packet delivery or packet sequence order

Question 20

When is UDP used?

Answer 20

When application protocols can tolerate missing/out-of-order packets

It’s often used for time-sensitive data like voice or video, where missing data causes glitches, not errors or connection failures.

Question 21

Why is UDP faster than TCP?

Answer 21

UDP has reduced overhead

Overhead is the extra data or processing needed for communication, beyond the essential payload.

Question 22

What can be used to control delivery reliability when using UDP?

Answer 22

Application layer

Question 23

2 protocols that use UDP?

Answer 23

• DHCP
• TFTP

Question 24

Why must DHCP use UDP?

Answer 24

DHCP uses broacast transmissions, which TCP doesn’t support

Broadcast sends data to all network devices at once.

If a response packet isn’t received, the client just restarts the provess & tries again repeatedly, until timing out

Question 25

Meaning of TFTP?

Answer 25

Trivial File Transfer Protocol

Question 26

Purpose of TFTP?

Answer 26

For network devices to obtain a configuration file

Question 27

Why doesnt TFTP require TCP?

Answer 27

It has it's own built-in mechanism for acknowledging messages

Question 28

Meaning of FTP?

Answer 28

File Transfer Protocol

Question 29

FTP--Data connection port? | This port handles actual file transfers

Answer 29

TCP/20

Question 30

FTP--Control connection port? | This port manages commands & responses

Answer 30

TCP/21

Question 31

# Identify port TCP/20

Answer 31

FTP-Data connection

Question 32

# Identify port TCP/21

Answer 32

FTP-Control connection

Question 33

Purpose of FTP?

Answer 33

Transfer files across a network

Question 34

Meaning of SSH?

Answer 34

Secure Shell

Question 35

Purpose of SSH protocol?

Answer 35

Make a secure connection to the command-line interface of a server

Question 36

SSH protocol port?

Answer 36

TCP/22

Question 37

# Identify port TCP/22

Answer 37

SSH

Question 38

Purpose of Telnet protocol?

Answer 38

Make an unsecure connection to the command-line interface of a server

Question 39

Telnet protocol port?

Answer 39

TCP/23

Question 40

# Identify port TCP/23

Answer 40

Telnet

Question 41

Meaning of SMTP?

Answer 41

Simple Mail Transfer Protocol

Question 42

Purpose of SMTP?

Answer 42

Transfer emails across a network

Question 43

SMTP port?

Answer 43

TCP/25

Question 44

# Identify port TCP/25

Answer 44

SMTP

Question 45

Meaning of DNS?

Answer 45

Domain Name System

Question 46

Purpose of DNS protocol?

Answer 46

Allow hosts to be identified by name & IP addresses

Question 47

DNS protocol port?

Answer 47

(TCP or UDP)/53

Question 48

# Identify port (TCP or UDP)/53

Answer 48

DNS

Question 49

Meaning of DHCP?

Answer 49

Dynamic Host Configuration Protocol

Question 50

Purpose of DHCP Server?

Answer 50

Provision an IP address configuration to clients

Question 51

DHCP Server port?

Answer 51

UDP/67

Question 52

# Identify port UDP/67

Answer 52

DHCP Server

Question 53

Purpose of DHCP Client?

Answer 53

Request a dynamic IP address configuration from a server

Question 54

DHCP Client port?

Answer 54

UDP/68

Question 55

# Identify port UDP/68

Answer 55

DHCP Client

Question 56

Meaning of HTTP?

Answer 56

HyperText Transfer Protocol

Question 57

Purpose of HTTP?

Answer 57

Provision unsecure websites & web services

Question 58

HTTP port?

Answer 58

TCP/80

Question 59

# Identify port TCP/80

Answer 59

HTTP

Question 60

Meaning of POP?

Answer 60

Post Office Protocol

Question 61

Purpose of POP? | Examples of POP clients are Microsoft Outlook & Mozilla Thunderbird

Answer 61

Retrieve emails from a server mailbox

Question 62

POP port?

Answer 62

TCP/110

Question 63

# Identify port TCP/110

Answer 63

POP

Question 64

Purpose of NetBIOS over TCP/IP?

Answer 64

Support networking features of legacy Windows versions

Question 65

NetBIOS over TCP/IP port?

Answer 65

(UDP or TCP)/137-139

Question 66

# Identify port (UDP or TCP)/137-139

Answer 66

NetBIOS over TCP/IP

Question 67

Meaning of IMAP?

Answer 67

Internet Mail Access Protocol

Question 68

Purpose of IMAP?

Answer 68

Read & manage emails on a server mailbox

Question 69

IMAP port?

Answer 69

TCP/143

Question 70

# Identify port TCP/143

Answer 70

IMAP

Question 71

SNMP meaning?

Answer 71

Simple Network Management Protocol

Question 72

Purpose of SNMP?

Answer 72

Query status information from network devices ## Footnote SNMP enables remote monitoring and management of network devices, retrieving data for proactive troubleshooting and optimization.

Question 73

SNMP port?

Answer 73

UDP/161

Question 74

# Identify port UDP/161

Answer 74

SNMP

Question 75

Purpose of SNMP trap operation?

Answer 75

Report status info. to a management server

Question 76

SNMP trap operation port?

Answer 76

UDP/162

Question 77

# Identify port UDP/162

Answer 77

SNMP trap operation

Question 78

Meaning of LDAP?

Answer 78

Lightweight Directory Access Protocol

Question 79

Purpose of LDAP?

Answer 79

Query info about network users & resources ## Footnote it allows systems to retrieve and search for data stored in a directory service, such as user accounts, groups, and network resources. This enables authentication, authorization, and information lookup across a network infrastructure.

Question 80

LDAP port?

Answer 80

TCP/389

Question 81

# Identify port TCP/389

Answer 81

LDAP

Question 82

Meaning of HTTPS?

Answer 82

HTTP Secure

Question 83

Purpose of HTTPS?

Answer 83

Provision secure websites & services

Question 84

HTTPS port?

Answer 84

TCP/443

Question 85

# Identify port TCP/443

Answer 85

HTTPS

Question 86

Meaning of SMB?

Answer 86

Server Message Block

Question 87

Purpose of SMB protocol?

Answer 87

Implement Windows-compatible file & printer sharing on a LAN ## Footnote SMB differs from FTP by being primarily used in Windows environments

Question 88

What is the SMB protocol also referred to?

Answer 88

CIFS

Question 89

Meaning of CIFS?

Answer 89

Common Internet File System

Question 90

SMB port?

Answer 90

TCP/445

Question 91

# Identify port TCP/445

Answer 91

SMB

Question 92

Meaning of RDP?

Answer 92

Remote Desktop Protocol

Question 93

Purpose of RDP?

Answer 93

Make a secure connection to the graphical desktop of a computer

Question 94

RDP port?

Answer 94

TCP/3389

Question 95

# Identify port TCP/3389

Answer 95

RDP

Question 96

What are application protocols?

Answer 96

Rules & conventions used by software to communicate over a network ## Footnote i.e. HTTP for web browsing, SMTP for email, FTP for file transfer, etc.

Question 97

Meaning of TCP?

Answer 97

Transmission Control Protocol