Network Time Protocol Version 4: Protocol and Algorithms Specification
RFC 5905
| Document | Type |
RFC - Proposed Standard
(June 2010; Errata)
Updated by RFC 7822
|
|
|---|---|---|---|
| Last updated | 2015-10-14 | ||
| Stream | IETF | ||
| Formats | plain text pdf html bibtex | ||
| Reviews | |||
| Stream | WG state | (None) | |
| Document shepherd | No shepherd assigned | ||
| IESG | IESG state | RFC 5905 (Proposed Standard) | |
| Consensus Boilerplate | Unknown | ||
| Telechat date | |||
| Responsible AD | Ralph Droms | ||
| Send notices to | (None) | ||
Internet Engineering Task Force (IETF) D. Mills
Request for Comments: 5905 U. Delaware
Obsoletes: 1305, 4330 J. Martin, Ed.
Category: Standards Track ISC
ISSN: 2070-1721 J. Burbank
W. Kasch
JHU/APL
June 2010
Network Time Protocol Version 4: Protocol and Algorithms Specification
Abstract
The Network Time Protocol (NTP) is widely used to synchronize
computer clocks in the Internet. This document describes NTP version
4 (NTPv4), which is backwards compatible with NTP version 3 (NTPv3),
described in RFC 1305, as well as previous versions of the protocol.
NTPv4 includes a modified protocol header to accommodate the Internet
Protocol version 6 address family. NTPv4 includes fundamental
improvements in the mitigation and discipline algorithms that extend
the potential accuracy to the tens of microseconds with modern
workstations and fast LANs. It includes a dynamic server discovery
scheme, so that in many cases, specific server configuration is not
required. It corrects certain errors in the NTPv3 design and
implementation and includes an optional extension mechanism.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc5905.
Mills, et al. Standards Track [Page 1]
RFC 5905 NTPv4 Specification June 2010
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than English.
Table of Contents
1. Introduction ....................................................4
1.1. Requirements Notation ......................................5
2. Modes of Operation ..............................................6
3. Protocol Modes ..................................................6
3.1. Dynamic Server Discovery ...................................7
4. Definitions .....................................................8
5. Implementation Model ...........................................10
6. Data Types .....................................................12
7. Data Structures ................................................16
7.1. Structure Conventions .....................................16
7.2. Global Parameters .........................................16
7.3. Packet Header Variables ...................................17
7.4. The Kiss-o'-Death Packet ..................................24
7.5. NTP Extension Field Format ................................25
8. On-Wire Protocol ...............................................26
9. Peer Process ...................................................30
9.1. Peer Process Variables ....................................31
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