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The Network Time Protocol Version 4 (NTPv4) MAC Extension Field

Document Type Expired Internet-Draft (ntp WG)
Expired & archived
Authors Danny Mayer , Harlan Stenn
Last updated 2016-09-15 (Latest revision 2016-03-14)
RFC stream Internet Engineering Task Force (IETF)
Intended RFC status (None)
Additional resources Mailing list discussion
Stream WG state Candidate for WG Adoption
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This Internet-Draft is no longer active.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:


The Network Time Protocol Version 4 (NTPv4) defines in RFC5905 the optional usage of Message Authentication Code (MAC). The MAC is an optional component of the NTP packet at the end of the packet. There can only be one MAC segment in the packet but there is no way of knowing if the last data segment at the end of an NTP packet is a MAC or an extension field, which is also defined in RFC5905. This draft defines a MAC extension field which will allow the existing MAC segment to be moved into an extension field and have a known length and deprecates the existing MAC.


Danny Mayer
Harlan Stenn

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