Port 25
Simple Mail Transfer Protocol - send email over internet
Port 23
Telnet
What port number is POP3?
110
Port 22
Secure Shell, Secure Copy, Secure-FTP
Port 80
HTTP
Port 80
Hyper-Text Transfer Protocol
Port 53
DNS
What port number is HTTP?
80
Port 23
Telnet - to create terminal session
Port 3389
RDP
Port 20/21
20 - used to transfer data
21 - used for control messages of the FTP sessions
Port 22
SSH / SFTP
What port number is Telnet?
23
Port 110/143
110 - Post Office Protocol - Version 3: reading email over the internet
143- Another internet protocol for reading email
Port 25
SMTP
Port 53
Domain Name System - used to query DNS server for IP address of a remote system
Port 110
POP3
What port number is SSH?
22
used by Domain Host Configuration Protocol client and server to automatically configure client
Port 20
FTP - Data
Port 443
Secure Hyper Text Transfer Protocol - for encryption of web traffic
Port 143
IMAP4
What port number is FTP - Control
21
Port 3389
Remote Desktop Protocol - used to remotely connect to and administer a system
Port 443
HTTPS