Port Number

Question 1

TCP- port 20/21

Answer 1

File Transfer Protocol - Use for transferring files between a client and a server on a computer network.
Port 21 is used for pass control information. And the other port 20 is used to send the data files between the client and the server.

Question 2

TCP- Port 22

Answer 2

Secure Shell (SSH)
- Provides a secure connection over an unsecured network.
Can be used to securely monitor devices.
More secure than SNMP.

Question 3

TCP- port 23

Answer 3

Telnet - Short for Teletype Network, provides a command line interface for communication with a remote device or server

Question 4

TCP port 25

Answer 4

SMTP (Simple Mail Transfers Protocol) - Allow the transmission of emails among user accounts over an internet connection.

Question 5

UDP port 53

Answer 5

Domain Name System
(DNS) - A hierarchical decentralized naming system for computers, services, or other resources connected to the internet, translating domain names into IP addresses.

Question 6

UDP port 67/68

Answer 6

Dynamic Host
Configuration Protocol (DHCP) - Automatically assigns IP addresses and other network configuration settings to devices on a network

First port is used by servers to receive client requests, while the other is used by clients to send requests to servers.

Question 7

TCP port 80

Answer 7

Hypertext Transfer Protocol
(HTTP)
- Used for transmitting data over the internet insecurely.

Question 8

TCP port 110

Answer 8

Post Office Protocol 3
(POP3) - A standard email protocol used to retrieve emails from a remote mail server to a local email client. It allows users to access their emails stored on the server and download them to their computer or mobile device for offline viewing.

Question 9

TCP port 137/139

Answer 9

Network Basic Input/
Output System (NetBIOS) –
NetBIOS over NetBIOSTCP/IP (NetBT) - Allow applications on different computers to communicate with each other across a local area network (LAN).
NetBIOS over TCP/IP (NetBT) extends NetBIOS to TCP/IP networks.

Question 10

TCP port 143

Answer 10

Internet Mail Access
Protocol (IMAP) - Allow users to retrieve emails from a mail server and manage them on their local devices.
Port 993 is the secure port of IMAP

Question 11

UDP 161/162

Answer 11

Simple Network
Management Protocol (SNMP) - Used to monitor and manage network devices, such as routers, switches, servers, and printers, on an IP network.

Question 12

TCP port 389

Answer 12

Lightweight Directory
Access Protocol (LDAP) - An open protocol for accessing and managing directory information services, providing a lightweight method for querying and modifying directory data.

Question 13

TCP port 443

Answer 13

Hypertext Transfer
Protocol Secure (HTTPS) - this port is used with Socket Secure Layer (SSL) VPNs, which provide Secure remote access to a corporate network over the Internet.

Question 14

TCP port 445

Answer 14

Server Message Block
(SMB)/Common Internet File System (CIFS) - used for providing shared access to files, printers, and other resources on a network.
CIFS is a specific implementation of the SMB.

Question 15

TCP port 3389

Answer 15

Remote Desktop Protocol
(RDP) - Allows users to remotely access and control a computer over a network.