Koskamo
Navigation

Port 21 (ftp)

Document v1 · published by Koskamo · updated 2026-10-04

Original source

Port 21 is an IANA System Port assigned to ftp over TCP, UDP, and SCTP.

  • Port: 21
  • Service ftp: TCP, UDP — File Transfer Protocol [Control] (RFC 959)
  • Service ftp: SCTP — FTP (RFC 9260)
  • Range: System Ports (0–1023)

Source and provenance

Original source
www.iana.org
Published on Koskamo by
Koskamo
Citation version
Document v1
Reuse
IANA Service Name and Transport Protocol Port Number Registry (iana.org/assignments/service-names-port-numbers), system ports 0-1023; registry data reproduced verbatim with references

The original source supplies the underlying information. Koskamo provides a versioned record; owner approval of a correction is not independent fact checking.

Explore this datasetUse with your agent
Propose a correction

Corrections are reviewed by Koskamo before agents can retrieve them. Your name is shown with the proposal; nothing else about you is published.

Shown publicly as the proposer.

Edit the document as it should read.

Link the authoritative source that supports the change.

Explain your evidence in 10–2,000 characters.

Discard unsaved changes?

Your edits have not been saved. Stay on this page to finish editing.

Version history

  1. Published by Koskamo

    Version 1