NTP for Windows Installer - Release Notes

Here you will find some version information about the Meinberg "NTP for Windows" Installer.

This page provides a changelog mainly for the setup program.

The changelog for the included NTP binaries can be found at https://www.ntp.org/:

• Known Vulnerabilities by Release Version
• 4.2.8-series Changelog

• Released 2025-09-17, 3945640 bytes, signed.

• Same NTP and OpenSSL binaries as in installer ntp-4.2.8p18a-win32-setup.exe (same signature):
  • NTP binaries built from ntp-4.2.8p18 release plus some patches that became available after p18.
  • OpenSSL DLL 3.0.17 (LTS) included.

• Older changes in the installer itself that were lost in ntp-4.2.8p18-win32-setup.exe and ntp-4.2.8p18a-win32-setup.exe were re-added.

• Changes in the default ntp.conf file created by the installer:
  • Updated default restrictions
  • Updated many comments and URLs

• Changes to ntp.conf are only visible if the installer creates a new file, but not if an existing file is retained across an update.

• This installer is smaller than earlier versions because obsolete, unused stuff was removed.

• Released 2025-09-12, 4848856 bytes, signed, withdrawn.

• NTP binaries built from ntp-4.2.8p18 release plus some patches that became available after p18.

• OpenSSL DLL 3.0.17 (LTS) included (same as in installer 4.2.8p18, but new signature).

• Installer withdrawn later for the same reasons as the ntp-4.2.8p18-win32-setup.exe version.

• Released 2025-09-10, 4849680 bytes, signed, withdrawn.

• First release after ntp-4.2.8p15a-win32-setup.exe.

• NTP binaries built from ntp-4.2.8p18 release.

• OpenSSL DLL 3.0.17 (LTS) included.

• Installer version built from NSIS scripts that were migrated to a new repo.

• Installer withdrawn later because unfortunately some fixes and improvements from earlier installer versions were lost during the migration.

• Released 2023-04-19, 4455280 bytes, signed.

• Provides NTP binaries which include security fixes implemented after the 4.2.8p15 release. See:
  NTP Vulnerabilities Reported 2023-04

• OpenSSL DLL 1.1.1t included.

• Released 2021-02-24, 4501392 bytes, signed.

• Fixes a bug in the installer where the ImagePath registry entry was unquoted. See:
  Securing the NTP Service Installation on Windows

• OpenSSL DLL 1.1.1j included.

• Released 2020-07-03, 4502008 bytes, signed.

• NTP binaries 4.2.8p15.

• OpenSSL DLL 1.1.1g included.

• Released 2020-04-20, 4500432 bytes, signed.

• NTP binaries 4.2.8p14.

• OpenSSL DLL 1.1.1f included.

• Released 2019-03-08, 3995928 bytes, signed.

• NTP binaries 4.2.8p13.

• OpenSSL DLL 1.0.2p included.

• Released 2018-08-28, 3995872 bytes, signed.

• NTP binaries 4.2.8p12.

• OpenSSL DLL 1.0.2p included.

• Released 2018-03-09, 3987848 bytes, signed.

• NTP binaries 4.2.8p11.

• OpenSSL DLL 1.0.2n included.

• Released 2017-03-23, 4347792 bytes, signed.

• NTP binaries 4.2.8p10.

• OpenSSL DLL 1.0.2k included.

• Released 2016-12-02, 3904656 bytes, signed.

• NTP binaries 4.2.8p9.

• OpenSSL DLL 1.0.1u included.

• Released 2016-06-06, 3901440 bytes, signed.

• NTP binaries 4.2.8p8.

• OpenSSL DLL 1.0.1s included.

• Released 2016-04-28, 3908800 bytes, signed.

• NTP binaries 4.2.8p7.

• OpenSSL DLL 1.0.1s included.

• See https://www.ntp.org/support/securitynotice/4_2_8p7-release-announcement/

• Released 2016-01-12, 3888312 bytes, signed.

• NTP binaries 4.2.8p5.

• OpenSSL DLL 1.0.1q included.

• Released 2015-11-16, 3886856 bytes, signed.

• NTP binaries build from 4.2.8p4 plus some patches applied by Meinberg after the 4.2.8p4 release.

• OpenSSL DLL 1.0.1p included.

• Released 2015-10-27, 3886856 bytes, signed.

• NTP binaries 4.2.8p4.

• OpenSSL DLL 1.0.1p included.

• Released 2015-07-09, 3898128 bytes, signed.

• NTP binaries 4.2.8p5.

• OpenSSL DLL 1.0.1p included.

• Released 2015-05-29, 4156192 bytes, signed.

• NTP binaries 4.2.8p2.

• OpenSSL DLL 1.0.1m included.

• Released 2014-12-22, 4156272 bytes, signed.

• NTP binaries 4.2.8.

• OpenSSL DLL 1.0.1j included.

• Released 2014-06-03, 3782592 bytes, signed.

• Improved installer

• NTP binaries 4.2.6p5@2349 (same as in ntp-4.2.6p5@spider-man-win32-setup.exe).

• OpenSSL DLL 1.0.1g included (same as in ntp-4.2.6p5@spider-man-win32-setup.exe).

• Released 2014-05-07, 3782600 bytes, signed.

• NTP binaries 4.2.6p5@2349.

• OpenSSL DLL 1.0.1g included.

• Released 2012-08-15, 3769800 bytes, signed.

• NTP binaries ntp-4.2.6p5.

• OpenSSL DLL 1.0.1c included.

• Version 1.0.1c of the OpenSSL DLL is affected by the OpenSSL heartbleed bug.
  On the other hand, the NTP programs don't use the affect OpenSSL functions.

• Same installer binary as ntp-4.2.6p5@london-o-win32-setup.exe.

• Released 2012-08-15, 3769800 bytes, signed.

• NTP binaries ntp-4.2.6p5.

• OpenSSL DLL 1.0.1c included.

• Same installer binary as ntp-4.2.6p5@london-o-lpv-win32-setup.exe.

• Released 2009-12-09, 2951784 bytes, signed.

• Nickname “lennon” in memory of the death of John Lennon on December 8, 1980.

• NTP binaries 4.2.4p8 (NTP security update after p7).

• OpenSSL DLL 0.9.8l included.

• See https://www.meinbergglobal.com/english/news/software-new-ntp-version-for-windows-4-2-4p8-security-update.htm

• Released , bytes, signed.

• NTP binaries .

• OpenSSL DLL included.

• Released 2009-05-22, 2951536 bytes, signed.

• NTP binaries 4.2.4p7.

• OpenSSL DLL 0.9.8k included.

• Security fixes.

• See https://www.meinbergglobal.com/english/news/software-new-ntp-version-4-2-4p7-for-windows-security-update.htm

• Released 2009-01-13, 2950168 bytes, signed.

• NTP binaries ntp-4.2.4p6.

• OpenSSL DLL 0.9.8j included.

• Fixed a bug in ntpd from ntp-4.2.4p6@vegas where ntpd didn't mobilize associations
  if DNS names of configured remote servers couldn't be resolved immediately at startup.

• The fix was to re-compile the NTP binaries from the same source code, but with flag FORCE_DNSRETRY
  defined, which was not in the default config.h file used for build on Windows.

• Released 2009-01-08, 2943112 bytes, signed.

• Nickname “vegas” due to the CES that was happening in Las Vegas, Nevada, when the package was published.

• NTP binaries 4.2.4p6 (security update).

• OpenSSL DLL 0.9.8j included.

• See http://www.meinberg.de/english/news/software-new-ntp-version-for-windows-4-2-4p6-security-update.htm

• Released 2008-09-01, 2943504 bytes, signed.

• Nickname “beijing” due to the 2008 Olympic Games.

• NTP binaries 4.2.4p5.

• OpenSSL DLL 0.9.8e included.

• ntpd now handles delayed initialization of network interfaces gracefully, e.g. on mobile devices.

• The installer configures a 3 seconds update interval for the network interfaces (parameter -U 3),
  i.e., ntpd scans for interface changes every 3 seconds.

• ntpd now honors command line parameters that were entered in the SCM management console.

• A few minor improvements of the installer itself.

• See: https://www.meinbergglobal.com/english/news/new-ntp-version-for-windows-4-2-4p5-.htm

• Released 2007-12-05, 2900016 bytes.

• NTP binaries 4.2.4p4@1.1520.

• OpenSSL DLL 0.9.8e included.

• Installs the NTP Time Server Monitor by default, but this can be deselected.

• See https://www.meinbergglobal.com/english/news/new-ntp-version-for-windows-4-2-4p4-.htm

• Nickname “modena” in honor of Luciano Pavarotti, the famous Italian tenor,
  who died shortly before this release.

• Released 2007-08-06 , 1983328 bytes, signed.

• NTP binaries 4.2.4p3@1.1502.

• OpenSSL DLL 0.9.8e included.

• Windows firewall handling now works in unattended/silent install mode as well.

• FW checking can be turned off during interactive installs (additional checkbox).

• Installer now creates start menu entries for generic start/stop/restart and status query scripts which are included in the installer.

• A start menu entry for editing the configuration file helps users to actually find it better.

• A few web links were added to the start menu as well.

• Creation of start menu entries can be deselected, of course.

• Released 2007-07-27, 1980992 bytes, signed.

• NTP binaries 4.2.4p3@1.1502.

• OpenSSL DLL 0.9.8e included.

• Released 2006-10-31, 1837097 bytes.

• NTP binaries 4.2.0a.

• OpenSSL DLL 0.9.8a included.

• Fixes a memory leak in the version of ntpd shipped with ntp-4.2.0a@mbg-fluxcap-o-win32-setup.exe.

• See https://groups.google.com/g/comp.protocols.time.ntp/c/7XT9v12W-xQ/m/ghtc68HseNIJ

• See https://www.meinbergglobal.com/english/news/bugfix-for-ntp-installer-fluxcap-.htm

• Released 2006-08-29, 1835196 bytes.

• NTP binaries based on ntp-4.2.0a.

• OpenSSL DLL 0.9.8a included.

• Based on an older NTP code base to avoid stability problems found binaries
  provided by earlier installer versions.

• Backports of some patches from the "xmas" edition.

• Leap second support on Windows not backported.

• Later turned out that ntpd in this version has a memory leak, so ntp-4.2.0a@mbg-fluxcap-v2-o-win32-setup.exe was released to fix this.

• Nickname “fluxcap” in memory of the flux capacitor in “Back to the Future”,
  because this version is based on an older code base.

• Released 2005-12-22, 1838976 bytes.

• NTP binaries 4.2.0b@1.1436-mbg.

• OpenSSL DLL 0.9.8a included.

• Nickname “xmas” because it was released very shortly before christmas, to ensure that
  the leap second scheduled for the end of the year was also processed correctly under Windows.

• Since then-current Windows versions didn't support the concept of leap seconds at all,
  ntpd simply slows down the Windows system clock for 2 seconds so that after the 2 seconds
  the system time is back in line with the new UTC time after the just-inserted leap second.
  See https://bugs.ntp.org/show_bug.cgi?id=508

• The source code is kept in a repo named ntp-dev-20051222a, which is based on the official NTP code base,
  but with changes from Harlan Stenn and Danny Mayer, as well as these improvements by Martin Burnicki:

• The Windows system clock is slewed quickly (in a 2 second period) to account for an inserted leap second.

• Detection of a leap second announcement, and insertion of a leap second are reported in the event log.

• If the new parameter -M is given on the command line, the NTP service sets the Windows multimedia timer
  to highest resolution as long as the service is active. This prevents the Windows system time from
  stepping back and forth when other applications modify the multimedia timer, as discussed several times
  in the NTP newsgroup comp.protocols.time.ntp.

• An event log message is generated if the service is stopped.

• The statistics file is now by default correctly named sysstats instead of systats.
  This has simply be achieved by changing the definition of STANAME.

• getaddrinfo() and friends are imported from the OS at runtime, if available, otherwise
  the built-in functions are used.

• The code changes were later submitted to the NTP project and integrated into the NTP code base.

• This version of ntpd runs mostly stable on most systems, even under high load.
  However, unfortunately it also traps sometimes on a couple of systems, which is why
  the ntp-4.2.0a@mbg-fluxcap version was released, which was based
  on an earlier version of the source code which didn't have the stability problem.
  See https://bugs.ntp.org/show_bug.cgi?id=527#c34.

• Released 2005-10-16, 1821181 bytes, withdrawn

• NTP binaries 4.2.0b@1.1417.

• OpenSSL DLL 0.9.8 included.

• Withdrawn due to stability problems.

• Released 2005-04-12, 1685553 bytes.

• NTP binaries 4.2.0a@1.1370.

• OpenSSL DLL 0.9.7g included.

• Released 2005-04-07, 1685514 bytes.

• NTP binaries 4.2.0a@1.1354.

• OpenSSL DLL 0.9.7g included.

• Released 2005-04-05, 1692613 bytes.

• NTP binaries 4.2.0a@1.1367.

• OpenSSL DLL 0.9.7f included.

• Released 2005-03-31, 1673299 bytes.

• NTP binaries 4.2.0a@1.1358.

• OpenSSL DLL 0.9.7f included.

— Martin Burnicki martin.burnicki@meinberg.de, last updated 2025-09-22