- SMTP
SMTP typically uses TCP port 25
- HTTP
HTTP is typically implemented using TCP port 80.
- HTTPS
HTTPS is a lower level Application Layer protocol that typically uses TCP port 443 by default.
- FTP
File Transfer Protocol first establishes, then maintains a control connection throughout the session over TCP port 21. Then a second connection is opened over TCP port 20 for data transfer.
- TELNET
TELNET typically uses TCP port 23.
- IMAP
Internet Message Access Protocol - TCP/143
- RDP
Microsoft Terminal Server - 3389
- SSH
Secure Shell - 22
- DNS
Domain Name System - 53
- DHCP
Dynamic Host Configuration Protocol - UDP/67, UDP/68