Common Network Ports

Question 1

What is the purpose of port 20/21 and what protocol is associated with it?

Answer 1

Port 20/21 is used for FTP (File Transfer Protocol) which is used for sending files over the internet. P20 is for sending commands to the server, P21 is for sending data.

Question 2

Which protocol uses port 22 and what is its purpose?

Answer 2

SSH (Secure Shell) uses port 22 and is used for secure remote access to a server or computer. Establishes secure connection and exchanges data between client and server. [used to access command line interface (CLI) of computer/server]

Question 3

Which protocol uses port 23 and what is its purpose?

Answer 3

Telnet uses port 23 and is used for remote access to a server or computer (unencrypted). Establishes a connection and exchanges data between client and server. [used to access command line interface (CLI) of computer/server]

Question 4

Which protocol uses port 25 and what is its purpose?

Answer 4

SMTP (Simple Mail Transfer Protocol) uses port 25 and is used for sending email messages between mail servers.

Question 5

Which protocol uses port 53 and what is its purpose?

Answer 5

DNS (Domain Name System) uses port 53 and is used for converting domain names into IP addresses.

Question 6

Which protocol uses port 80 and what is its purpose?

Answer 6

HTTP (Hypertext Transfer Protocol) uses port 80 and is used for sending and receiving data between web servers and web clients.

Question 7

Which protocol uses port 110 and what is its purpose?

Answer 7

POP3 (Post Office Protocol version 3) uses port 110 and is used for retrieving email messages from a mail server. Establishes simple connection and retrieves email messages (unsynchronized).

Question 8

Which protocol uses port 143 and what is its purpose?

Answer 8

IMAP (Internet Message Access Protocol) uses port 143 and is used to retrieve email messages from a mail server. Establishes connection and retrieves email messages (synchronized).

Question 9

Which protocol uses port 443 and what is its purpose?

Answer 9

HTTPS (Hypertext Transfer Protocol Secure) uses port 443 and is used for sending and receiving encrypted and secure data between web servers and web clients.

Question 10

Which protocol uses port 3389 and what is its purpose?

Answer 10

RDP (Remote Desktop Protocol) uses port 3389 and is used for remote access to a computer. Establishes a connection and exchange data between client and server. [used to access graphical user interface (GUI) of a computer]