RFC 4250 · PROPOSED STANDARD · 2006

The Secure Shell Protocol Assigned Numbers

Overview

RFC 4250, “The Secure Shell Protocol Assigned Numbers”, is a Proposed Standard document published in January 2006 by S. Lehtinen, C. Lonvick. It has since been updated by RFC 8268, RFC 9142, RFC 9519. The canonical text is published by the RFC Editor.

Abstract

This document defines the instructions to the IANA and the initial state of the IANA assigned numbers for the Secure Shell (SSH) protocol. It is intended only for the initialization of the IANA registries referenced in the set of SSH documents. [STANDARDS-TRACK]

Abstract as published in the RFC, via rfc-editor.org.

What “Proposed Standard” means

An entry-level standards-track specification: stable, peer-reviewed and a solid basis for implementation, though it may still evolve before becoming an Internet Standard.

Read this RFC

The canonical text of RFC 4250 is hosted at rfc-editor.org. Available in TXT,HTML.

Relationships to other RFCs
Other RFCs from 2006

Who Is Online

In total there are 41 users online: 0 registered, 34 guests and 7 bots.

Most users ever online was 1,226 on 13 Jun 2026, 3:56 am.

Bots: AhrefsBot Applebot Bingbot Googlebot Other Bot SemrushBot Sogou

Users active in the past 15 minutes. Total registered members: 354