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Network Time Protocol REFID Updates

Document Type Expired Internet-Draft (ntp WG)
Expired & archived
Authors Harlan Stenn , Sharon Goldberg
Last updated 2019-09-26 (Latest revision 2019-03-25)
Replaces draft-stenn-ntp-ipv6-refid-hash, draft-stenn-ntp-not-you-refid
RFC stream Internet Engineering Task Force (IETF)
Intended RFC status (None)
Additional resources Mailing list discussion
Stream WG state In WG Last Call
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This Internet-Draft is no longer active.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:


RFC 5905 [RFC5905], section 7.3, "Packet Header Variables", defines the value of the REFID, the system peer for the responding host. In the past, for IPv4 associations the IPv4 address is used, and for IPv6 associations the first four octets of the MD5 hash of the IPv6 are used. There are two recognized shortcomings to this approach, and this proposal addresses them. One is that knowledge of the system peer is "abusable" information and should not be generally available. The second is that the four octet hash of the IPv6 address looks very much like an IPv4 address, and this is confusing. RFC EDITOR: PLEASE REMOVE THE FOLLOWING PARAGRAPH BEFORE PUBLISHING: The source code and issues list for this draft can be found in


Harlan Stenn
Sharon Goldberg

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