| 协议 | 端口号 | 描述 |
| tcp/udp | 0 | Reserved |
| tcp/udp | 1 | TCP Port Service Multiplexer |
| udp | 1 | Sockets des Troie |
| tcp | 2 | Death |
| tcp/udp | 2 | Management Utility |
| tcp/udp | 3 | Compression Process |
| tcp/udp | 3 | Midnight Commander Sometimes this program is assigned to this port |
| tcp | 4 | Midnight Commander Sometimes this program is assigned to this prot |
| tcp | 4 | Self-Certifying File System(SFS) sfssd acceps connections on TCP port 4 and passes them to the appropriate SFS daemon. SFS is a secure, global file system with completely decentralized control. SFS uses NFS 3 as the underlying protocol for file access. |
| tcp/udp | 4 | Unassigned |
| tcp/udp | 5 | Remote Job Entry |
| tcp/udp | 6 | Unassigned |
| tcp/udp | 7 | Echo |
| tcp/udp | 8 | Unassigned |
| 9 | Discard SC:DISC |
| tcp/udp | 9 | Discard |
| tcp/udp | 10 | Unassigned |
| tcp/udp | 11 | Active Users |
| tcp/udp | 12 | Unassigned |
| tcp/udp | 13 | Daytime (RFC 867) |
| tcp/udp | 14 | Unassigned |
| tcp | 15 | Unassigned [was netstat] |
| tcp/udp | 15 | Unassigned |
| tcp/udp | 17 | Quote of the Day |
| tcp/udp | 18 | Message Send Protocol |
| tcp/udp | 19 | Character Generator |
| tcp | 20 | Randex |
| tcp/udp | 20 | File Transfer [Default Data] |
| tcp | 21 | Back Construction |
| tcp | 21 | Blade Runner |
| tcp | 21 | Cattivik FTP Server |
| tcp | 21 | CC Invader |
| tcp | 21 | Dark FTP |
| tcp | 21 | Doly Trojan |
| tcp | 21 | Fore |
| tcp | 21 | Invisible FTP |
| tcp | 21 | Juggernaut 42 |
| tcp | 21 | Larva |
| tcp | 21 | MotIv FTP |
| tcp | 21 | Net Administrator |
| tcp | 21 | Ramen |
| tcp | 21 | Senna Spy FTP server |
| tcp | 21 | The Flu |
| tcp | 21 | Traitor 21 |
| tcp | 21 | W32.Bobax |
| tcp | 21 | W32.Loxbot |
| tcp | 21 | W32.Mytob |
| tcp | 21 | WebEx |
| tcp | 21 | WinCrash |
| tcp/udp | 21 | File Transfer [Control] |
| tcp | 22 | Shaft |
| tcp/udp | 22 | SSH Remote Login Protocol |
| udp | 22 | pcAnywhere(Used in older versions, though newer version still use it for backwards compatibility.) |
| tcp | 23 | Dagonit |
| tcp | 23 | Fire HacKer |
| tcp | 23 | MindControl |
| tcp | 23 | Tiny Telnet Server - TTS |
| tcp | 23 | Truva Atl |
| tcp/udp | 23 | Telnet |
| tcp/udp | 24 | any private mail system |
| tcp | 25 | Ajan |
| tcp | 25 | Antigen |
| tcp | 25 | Bancos |
| tcp | 25 | Barok |
| tcp | 25 | Chimo |
| tcp | 25 | Email Password Sender - EPS |
| tcp | 25 | EPS II |
| tcp | 25 | Gip |
| tcp | 25 | Gris |
| tcp | 25 | Happy99 |
| tcp | 25 | Hpteam mail |
| tcp | 25 | Hybris |
| tcp | 25 | I love you |
| tcp | 25 | Kuang2 |
| tcp | 25 | Magic Horse |
| tcp | 25 | MBT (Mail Bombing Trojan) |
| tcp | 25 | Mitglieder |
| tcp | 25 | Moscow Email trojan |
| tcp | 25 | Naebi |
| tcp | 25 | NewApt worm |
