TABLE OF CONTENTS A table of well-known ports
A selection of a few widely used registered ports
Software ports are used by TCP/IP to associate segments with application programs running on a host that receives a message. The wellknown ports are those used primarily by communications processes and other privileged applications, and have numbers between 0 and 1023.
| Note | Application developers can register ports for their programs with IANA. Registered ports are in the range of 1024 through 49151. Ports between 49152 and 65536 are dynamic and/or private. |
The following table contains a selection of well-known ports that you may want your firewall to block. In almost all cases, both TCP and UDP have the same port number assignments. Registered Ports
| Port | Protocol or Application |
|---|---|
| 1 | TCP Port Service Multiplier (TCPMUX) |
| 5 | Remote Job Entry (RJE) |
| 7 | ECHO |
| 17 | Quote of the Day |
| 18 | Message Send Protocol (MSP) |
| 20 | FTP (default data port) |
| 21 | FTP (control port) |
| 22 | SSH Remote Login Protocol |
| 23 | Telnet |
| 24 | Any private mail system |
| 25 | SMTP |
| 29 | MSG ICP |
| 35 | Any private print server |
| 37 | Time |
| 38 | Remote Access Protocol |
| 39 | Remote Location Protocol |
| 41 | Graphics |
| 42 | Host Name Server |
| 43 | WhoIs |
