TCP port number and its application
| The port number | protocol | Explanation |
|---|---|---|
| 21 | FTP | File Transfer Protocol |
| 23 | Telnet | For remote login, you can control the target computer |
| 25 | SMPT | SMPT server is an open port for sending mail |
| 80 | HTTP | Hypertext Transfer Protocol |
| 110 | POP3 | Receive mail |
| 443 | HTTPS | Encrypted Hypertext Transfer Protocol |
| 1521 | Oracle database service |
UDP port number used some
| The port number | protocol | Explanation |
|---|---|---|
| 53 | DNS | Domain Name Resolution Protocol |
| 69 | TFTP | Simple file transfer protocol |
| 123 | NTP | Network Time Protocol |