NTP: The Network Time Protocol

NTP users are strongly urged to take immediate action to ensure that their NTP daemon is not susceptible to use in a reflected denial-of-service (DRDoS) attack. Please see the NTP Security Notice for vulnerability and mitigation details, and the Network Time Foundation Blog for more information. (January 2014)

Welcome to ntp.org, home of the Network Time Protocol project.

This page is home for the NTP Project (R&D). This web site, and all pages directly contained within, are in the public domain. Some portions of this site may be copyrighted by other authors. Please contact the webmaster with any questions regarding copyright. The NTP software distribution is copyrighted, as described in the NTP copyright page.

NTP is a protocol designed to synchronize the clocks of computers over a network.

NTP version 4, a significant revision of the previous NTP standard, is the current development version. It is formalized by RFCs released by the IETF.

The NTP Project (R&D)

The NTP Project conducts Research and Development in NTP and produces the Official Reference Implementation of NTP along with the Implementation Documentation. Background information about NTP, along with briefings and a bibliography, are available at the Network Time Synchronization Project Page.

The NTP Public Services Project

The NTP Public Services Project, which is hosted by Internet Systems Consortium, Inc., provides support and additional development resources for the Official Reference Implementation of NTP. The available resources include:

Please direct comments and questions about this web site to the NTP Project webmaster. To contact the NTP Public Services Project web maintainers or any member of the NTP developer team, please see the NTP Public Services Project Contact Page.