NTP users are strongly urged to take immediate action to ensure that their NTP daemons are not susceptible to being used in distributed denial-of-service (DDoS) attacks. Please also take this opportunity to defeat denial-of-service attacks by implementing Ingress and Egress filtering through BCP38.

ntp-4.2.8p15 was released on 23 June 2020. It addresses 1 medium-severity security issue in ntpd, and provides 13 non-security bugfixes over 4.2.8p13.

Please see the NTP Security Notice for vulnerability and mitigation details.

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Are you using Autokey in production? If so, please contact Harlan - he's got some questions for you.

NTP Software Development

New users should consult the documentation page before contacting the NTP development team with questions.

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Bugzilla

Tracking of NTP bugs or enhancement requests is done using Bugzilla, an open-source bug tracking system developed by the the Mozilla team. Our Bugzilla server is located at bugs.ntp.org. All users need a unique Bugzilla account, which can be created from the Bugzilla page. Users are encouraged to report bugs or suggest enhancements.

Source releases and patches

The development tarballs available in the HTTP archive are sometimes not suitable for production work, but the dev team produces development tarballs to provide users with specific needs the ability to get semi-stable software with important, new features that may not be available in the stable tree. Having said that, we generally run the development branch on our machines. While there are sometimes problems, when problems happen we tend to fix them very quickly.

Tarballs (for both the current release and development versions) are available from the software downloads page. Patch files, and other tarballs, are available in the HTTP archive.

NTP Source Code Repositories

The NTP source is maintained in two branches. The -stable branch, which has an even release number, and a dev, or master branch, which has an odd release number.

These repositories and branches are published in several different ways:

• Master git repositories are published at https://github.com/ntp-project/ntp .
• BitKeeper repositories are published at http://bk.ntp.org .
• Via rsync, from http://archive.ntp.org. Use rsync archive.ntp.org:: to see the targets.

The git, bk, and rsync repositories are fully and automatically synchronized.

Tools Needed to build from a repository

Building NTP from a tarball needs the fewest tools. To build from a repository you must have the following tools installed:

• autoconf - Version 2.61 or later. We use the latest version.
• automake - Version 1.11 or later. We use the latest version.
• libtool - Version 1.5.something (this is a guess - we use something recent).
• lynx - Any version. We use this to generate the COPYRIGHT file.

The following tools are only needed if you are planning to hack on the .def files which produce our command-line parsing and our generated documentation. Almost nobody will ever need these:

• autogen - Version 5.18.5 or later. We are currently using 5.18.5.
• guile - needed by autogen.

Getting the code

Using git

To get a copy of ntp:

• git clone https://github.com/ntp-project/ntp.git

By default, you will get the ntp-stable branch. If you want to work with the development branch, go in to that directory and type:

• git checkout master

Using the open-source BitKeeper client

The NTP Project uses the open-source BitKeeper product.

You can get pre-compiled or source tarballs from https://www.bitkeeper.org/download.html .

There is more information available to NTP Project Committers at Info:GettingBk .

Once you have installed BitKeeper, you can clone the NTP repositories using the following commands:

For the ntp-stable repository, to ./ntp-stable:

   bk clone bk://bk.ntp.org/ntp-stable

For the ntp-dev repository, to ./ntp-dev:

   bk clone bk://bk.ntp.org/ntp-dev

Once you have the code on your computer

Once you have obtained the sources, do the following, using REPO as the directory the repository was downloaded to (e.g., ./ntp-stable or ./ntp-dev ):

   cd REPO
   ./bootstrap (To generate configure and Makefile.in files)

and you should be ready to go.

For information about hacking on the codebase, please see MaintainerIssues .

Keeping your repository up-to-date

git

You can keep your git repository up to date by running:

   cd REPO
   git pull

bk

You can keep your bk repository up to date by running:

   cd REPO
   bk pull -v

For help on a BitKeeper (bk) command (e.g. clone), use bk clone --help.