| Port | Description |
| 20 | File Transfer Protocol (FTP) Data Transfer |
| 21 | File Transfer Protocol (FTP) Command Control |
| 22 | SSH (Secure Shell) |
| 23 | Telnet |
| 25 | Simple Mail Transfer Protocol (SMTP) E-mail Routing |
| 53 | Domain Name System (DNS) service |
| 80 | Hypertext Transfer Protocol (HTTP) |
| 110 | Post Office Protocol (POP3)Â |
| 119 | Network News Transfer Protocol (NNTP) |
| 123 | Network Time Protocol (NTP) |
| 143 | Internet Message Access Protocol (IMAP) |
| 194 | Internet Relay Chat (IRC) |
| 443 | HTTP Secure (HTTPS) HTTP over TLS/SSL |
| 25565 | Minecraft server default port |
| 27015 | Source Games servers default port (Counter-strike) |
These are the most used and known ports. You have to open them for some applications to work.
For example, Minecraft uses port 25565
Counter-Strike servers are using 27015
Keep in mind that you can change ports if you want.
