1/* 2 * SPDX-License-Identifier: ISC 3 * 4 * Copyright (c) 2025 Lexi Winter <ivy@FreeBSD.org> 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19comment = "Network Time Protocol (NTP) daemon" 20 21desc = <<EOD 22The Network Time Protocol (NTP, RFC 5905) allows a system to set its time-of-day 23clock automatically by contacting a remote system known to have accurate time. 24NTP servers are typically organised in a hierarchy in which the highest-level 25servers receive time from a reliable external timekeeping device (such as an 26atomic clock or a GPS receiver), and each subordinate server in the hierarchy 27knows its distance from the timekeeping device it is ultimately synchronised to. 28 29Unlike earlier protocols such as the Time Protocol (RFC 868), NTP can provide 30very accurate (sub-millisecond) time synchronisation even over high-latency 31networks. Many NTP servers are accessible over the public Internet, most of 32which participate in the NTP Pool system. 33 34This package provides the ntpd(8) daemon which implements both the client 35and server part of NTP depending on its configuration, and the ntpdate(8) 36utility which can be used for testing or one-off time synchronisation. 37 38A periodic(8) script to monitor the status of the NTP daemon is also provided. 39EOD 40 41annotations { 42 set = "optional,optional-jail" 43} 44