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Software Downloads

Current versions of NTP

Source Code Releases

Release Version Date Download ChangeLog
Stable 4.2.6p5 2011/12/24 http/md5 http
Development 4.2.7p481 2014/11/22 http/md5 http

RSS Feed for Current releases of NTP

The NTP Reference Implementation is

Binary Releases

OS Architecture Release Version Download
Debian - Stable i386 Development Current Repository / ReadMe

Information and other download links

Stable Release NEWS

NTP 4.2.6p5 (Harlan Stenn , 2011/12/24)

Focus: Bug fixes

Severity: Medium

This is a recommended upgrade.

This release updates sys_rootdisp and sys_jitter calculations to match the RFC specification, fixes a potential IPv6 address matching error for the "nic" and "interface" configuration directives, suppresses the creation of extraneous ephemeral associations for certain broadcastclient and multicastclient configurations, cleans up some ntpq display issues, and includes improvements to orphan mode, minor bug fixes and code clean-ups.

New features / changes in this release:


  • Updated "nic" and "interface" IPv6 address handling to prevent mismatches with localhost [::1] and wildcard [::] which resulted from using the address/prefix format (e.g. fe80::/64)
  • Fix orphan mode stratum incorrectly counting to infinity
  • Orphan parent selection metric updated to includes missing ntohl()
  • Non-printable stratum 16 refid no longer sent to ntp
  • Duplicate ephemeral associations suppressed for broadcastclient and multicastclient without broadcastdelay
  • Exclude undetermined sys_refid from use in loopback TEST12
  • Exclude MODE_SERVER responses from KoD rate limiting
  • Include root delay in clock_update() sys_rootdisp calculations
  • get_systime() updated to exclude sys_residual offset (which only affected bits "below" sys_tick, the precision threshold)
  • sys.peer jitter weighting corrected in sys_jitter calculation


  • -n option extended to include the billboard "server" column
  • IPv6 addresses in the local column truncated to prevent overruns

more Complete NEWS file
more Complete Change Log

About the NTP Reference Implementation Source Releases

The NTP (R&D) Project only produces source code releases of The NTP Reference Implementation; users needing precompiled versions of NTP should see the links page. These releases may be installed using the standard Unix make command in conjunction with a compiler and all necessary libraries.

Please contact your operating system vendor for binary packages or assistance with your package-management system.

IDEA! The NTP version numbering page explains the version numbering scheme.

Browsing the Archives from the NTP (R&D) Project at www.ntp.org

Tarballs for production and development versions of The NTP Reference Implementation are available from the:

Obsolete versions of The NTP Reference Implementation are available from:

The NTP Public Services Project HTTP archive proxy is

Ports to other operating systems

Third-party implementations, including pre-compiled versions for operating systems such as Microsoft Windows, and some ports of the NTP package are linked to on the links page.

Receiving Notifications about new releases

Please visit ReleaseNotifications for more information about the many options available for receiving notifications about new NTP releases.

Topic attachments
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pngpng debian_swirl-16x16x32.png manage 0.6 K 2012-09-12 - 01:32 SteveKostecke 16x16 Debian Swirl
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