Common Ports And Protocols

Question 1

20 / 21

Answer 1

FTP
File Transfer Protocol

Port 20
Data transfer for file between client and server

Port 21 - Control
Manages control connection (commands for file servers)

Question 2

22

Answer 2

SHH
Secure Shell

Secure way to access and manage devices remotely over an encrypted connection

Question 3

23

Answer 3

Telnet

Unsecured way of accessing devices remotely, data isn’t encrypted

Question 4

25

Answer 4

SMTP
Simple Mail Transfer Protocol

Used for sending emails from a client to a mail server or between servers.

Question 5

53

Answer 5

DNS
Domain Name System

Resolves domain names (like www.example.com) into their corresponding IP addresses

Question 6

67 / 68

Answer 6

DHCP
Dynamic Host Configuration Protocol

Port 67
Used by the DHCP server to assign IP addresses to client devices.

Port 68
Used by the client to receive configuration information (IP, DNS, default gateway)

Question 7

80

Answer 7

HTTP
Hypertext Transfer Protocol

The standard protocol used for web communication, delivers unencrypted web pages to browsers.

Question 8

110

Answer 8

POP3
Post Office Protocol v3

Retrieves emails from the server to the local device, downloading and typically deleting them from the server

Question 9

143

Answer 9

IMAP
Internet Message Access Protocol

Allows email clients to retrieve and manage emails while keeping them stored on the server, enabling access from multiple devices.

Question 10

443

Answer 10

HTTPS
Hypertext Transfer Protocol Secure

Encrypted version of HTTP, used for secure communication over the web, uses SSL/TLS encryption to protect data.

Question 11

137 - 139

Answer 11

NetBIOS
Network Basic Input/Output System

Used for file and printer sharing over a local network, often with older systems.

Port 137
Provides name service for file and printer sharing

Port 138
Supports datagram service (connectionless communication)

Port 139
Facilitates session service for establishing and managing connections.

Question 12

445

Answer 12

SMB/CIFS
Server Message Block/Common Internet File System

Used for file sharing, network browsing, and printer sharing between devices on a network, especially in Windows environments.

Question 13

3389

Answer 13

RDP
Remote Desktop Protocol

Enables remote access and control of a desktop interface on a computer or server.

Question 14

389

Answer 14

LDAP
Lightweight Directory Access Protocol

Used to access and manage directory information services, such as user accounts and permissions in a network

Question 15

636

Answer 15

LDAPS
LDAP over SSL

Secure version of LDAP using SSL/TLS to encrypt communication between the client and the directory server

Question 16

161/162

Answer 16

SNMP
Simple Network Management Protocol

Allows for monitoring and managing network devices.

Port 161
Used by network devices (routers, switches) to send SNMP data to the server.

Port 162
Used by the management system to receive SNMP trap messages (alerts).

Question 17

123

Answer 17

NTP
Network Time Protocol

Used to synchronize the time across network devices.

Synchronizes the clocks of networked devices to a standard time source

Question 18

69

Answer 18

TFTP
Trivial File Transfer Protocol

A simplified version of FTP, used for transferring small files, like configuration files, without authentication or encryption.

Question 19

5060 / 5061

Answer 19

SIP
Session Initiation Protocol

Initiates, manages, and terminates multimedia communications (like VoIP)

Port 5060
Used for unencrypted voice communication in VoIP

Port 5061
Used for encrypted voice communication (SIP over TLS)

Question 20

1720

Answer 20

H.323

Used for VoIP (Voice over IP) and multimedia communication.

Question 21

5900

Answer 21

VNC
Virtual Network Computing

Remote desktop sharing protocol

Question 22

1433

Answer 22

Microsoft SQL Server

Used to connect to Microsoft SQL databases

Question 23

3306

Answer 23

MySQL Database

Used to connect to MySQL databases

Question 24

1521

Answer 24

Oracle Database

Used to connect to Oracle databases