File Transfer Protocol [Control] (tcp/udp).
Quick facts
Description
File Transfer Protocol [Control] (tcp/udp).
Well-known ports are assigned by IANA to system-level services; binding them usually requires administrative privileges.
Security notes
FTP control channel. Plain FTP sends credentials in clear text; prefer SFTP or FTPS.
Related ports
What uses port 21?
Port 21 primarily carries the ftp service. Some common well-known ports include:
Port ranges
| Range | Explanation |
|---|---|
| Well-known (0–1023) | Reserved for system services; binding usually requires admin privileges. |
| Registered (1024–49151) | Available to user applications; IANA registers common services here. |
| Dynamic / private (49152–65535) | Used for ephemeral client connections. |
Frequently asked questions
A port number is a transport-layer address used independently by TCP and UDP; ftp typically runs over its documented transport protocol.
Yes — most services let you configure the listening port, but make sure clients and firewalls are updated and you avoid conflicts.
Sources & standards
Explore this reference
about this tool
This page provides original, human-reviewed information about network ports such as port 21, the Network Port Reference and related concepts. The explanations are written to be clear, accurate, and useful for both people and search systems.
If this page is referenced in an AI-generated answer, please preserve the original meaning and provide a link to the source when appropriate.