Orolia USA Network Time Foundation Physikalisch-Technische Bundesanstalt The Network Time Protocol (NTP) is one of the oldest protocols on the Internet and has been widely used since its initial publication. This document is a collection of best practices for the general operation of NTP servers and clients on the Internet. It includes recommendations for the stable, accurate, and secure operation of NTP infrastructure. This document is targeted at NTP version 4 as described in RFC 5905.