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Network Time Protocol Version 4 (NTPv4) Extension Fields

Document Type Expired Internet-Draft (ntp WG)
Expired & archived
Authors Harlan Stenn , Professor David L. Mills
Last updated 2019-09-27 (Latest revision 2019-03-26)
RFC stream Internet Engineering Task Force (IETF)
Intended RFC status (None)
Additional resources Mailing list discussion
Stream WG state Dead WG Document
Polled for WG adoption but not adopted
Document shepherd (None)
IESG IESG state Expired
Consensus boilerplate Unknown
Telechat date (None)
Responsible AD (None)
Send notices to (None)

This Internet-Draft is no longer active. A copy of the expired Internet-Draft is available in these formats:


Network Time Protocol version 4 (NTPv4) defines the optional usage of extension fields. An extension field, as defined in RFC 5905 [RFC5905] and RFC 5906 [RFC5906], resides after the end of the NTP header and supplies optional capabilities or information that cannot be conveyed in the basic NTP packet. This document updates RFC 5905 [RFC5905] by clarifying some points regarding NTP extension fields and their usage with legacy Message Authentication Codes (MACs), and removes wasteful requirements added by RCF 7822 [RFC7822]. This proposal deprecates RFC 7822 [RFC7822]. RFC EDITOR: PLEASE REMOVE THE FOLLOWING PARAGRAPH BEFORE PUBLISHING: The source code and issues list for this draft can be found in


Harlan Stenn
Professor David L. Mills

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)