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UpdatedPROPOSED STANDARDIETF stream

RFC 5905: Network Time Protocol Version 4: Protocol and Algorithms Specification

Still current, but amended. Parts of this document are changed or extended by RFC 7822, RFC 8573, RFC 9109, RFC 9748, RFC 9769. Read both.

In plain English — editorial summary, not part of the RFC

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.

Document record

Document ID
RFC5905
Published
June 2010
Authors
D. Mills; J. Martin; J. Burbank; W. Kasch
Status
PROPOSED STANDARD
Stream
IETF
Area
int
Pages
110
Also known as
—
Obsoletes:
RFC 1305, RFC 4330
Updated by:
RFC 7822, RFC 8573, RFC 9109, RFC 9748, RFC 9769

Topics

Standards lineage

This document is one revision in a chain of 9 RFCs, each formally replacing the one before it.

  1. RFC 958 (1985)
  2. RFC 1059 (1988)
  3. RFC 1119 (1989)
  4. RFC 1305 (1992)
  5. RFC 1361 (1992)
  6. RFC 1769 (1995)
  7. RFC 2030 (1996)
  8. RFC 4330 (2006)
  9. RFC 5905 (2010)

Read the full history of Network Time Protocol Version 4: Protocol and Algorithms Specification →

Referenced by

5 later RFCs formally update or obsolete part of this document.

Related documents

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About this page

The document record above — title, authors, date, status, stream, area, relationships, DOI and errata — is imported verbatim from the public RFC Editor index. The “in plain English” section is editorial: written by The metasystema editorial team, not part of the RFC. Where the two differ, the RFC text governs.

Last checked against the RFC Editor index on . RFCs are never revised after publication; changes are issued as new documents.

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canonical URL: /rfc/5905-network-time-protocol-version-4-protocol-and-algorithms-specification