| Port | Description | status |
| 0/TCP,UDP | Reserved; do not use (but is a permissible source port value if the sending process does not expect messages in response) | Official |
| 1/TCP,UDP | TCPMUX (TCP port service multiplexer) | Official |
| 5/TCP,UDP | RJE (Remote Job Entry) | Official |
| 7/TCP,UDP | Official | |
| 9/TCP,UDP | DISCARD protocol | Official |
| 11/TCP,UDP | SYSTAT protocol | Official |
| 13/TCP,UDP | DAYTIME protocol | Official |
| 17/TCP,UDP | QOTD (Quote of the Day) protocol | Official |
| 18/TCP,UDP | Message Send Protocol | Official |
| 19/TCP,UDP | CHARGEN (Character Generator) protocol | Official |
| 20/TCP | FTP - data port | Official |
| 21/TCP | FTP - control (command) port | Official |
| 22/TCP,UDP | SSH (Secure Shell) - used for secure logins, file transfers (scp, sftp) and port forwarding | Official |
| 23/TCP,UDP | Telnet protocol - unencrypted text communications | Official |
| 25/TCP,UDP | Official | |
| 26/TCP,UDP | RSFTP - A simple FTP-like protocol | Unofficial |
| 35/TCP,UDP | QMS Magicolor 2 printer | Unofficial |
| 37/TCP,UDP | Official | |
| 39/TCP,UDP | Resource Location Protocol | Official |
| 41/TCP,UDP | Graphics | Official |
| 42/TCP,UDP | Host Name Server | Official |
| 42/TCP,UDP | Unofficial | |
| 43/TCP | WHOIS protocol | Official |
| 49/TCP,UDP | TACACS Login Host protocol | Official |
| 53/TCP,UDP | DNS (Domain Name System) | Official |
| 56/TCP,UDP | Route Access Protocol | Official |
| 57/TCP | MTP, Mail Transfer Protocol |
|
| 67/UDP | BOOTP (BootStrap Protocol) server; also used by DHCP (Dynamic Host Configuration Protocol) | Official |
| 68/UDP | Official | |
| 69/UDP | TFTP (Trivial File Transfer Protocol) | Official |
| 70/TCP | Gopher protocol | Official |
| 79/TCP | Official | |
| 80/TCP | HTTP (HyperText Transfer Protocol) - used for transferring web pages | Official |
| 81/TCP | HTTP Alternate (HyperText Transfer Protocol) | Official |
| 81/TCP | Torpark - Onion routing ORport | Unofficial |
| 82/UDP | Torpark - Control Port | Unofficial |
| 88/TCP | Kerberos - authenticating agent | Official |