NTP 守護進程：OpenNTPD

OpenNTPD是一個Unix系統網絡時間協議（NTP）實現的守護進程，可以使計算機系統的本地時鐘與遠程NTP服務器同步。它也可以作為一個NTP兼容客戶端的NTP服務器。

OpenNTPD作為OpenBSD計劃的一部分，主要由亨寧·布勞爾負責開發。其設計目標包括安全（不可被利用）、易于配置、在大多數情況足夠精確及可在BSD許可證下分發源代碼。如OpenSSH，它另有一個單獨的子項目來開發可移植版本，其為OpenBSD的版本添加了兼容性代碼，且與主項目分開發布新版本。可移植版由達倫·塔克開發。最新的可移植版發布于2006年。該項目的開發者得到了一些來自OpenBSD基金會的資助。

OpenNTPD逐步調整系統時鐘，如在64位Arch Linux系統上運行OpenNTPD輸出示例所示：

[root@nikolai karam]# more /var/log/daemon.log | grep ntp | grep adjusting | tail -20
Aug  4 02:58:21 nikolai ntpd[4784]: adjusting local clock by -2.134620s
Aug  4 03:02:38 nikolai ntpd[4784]: adjusting local clock by -1.983869s
Aug  4 03:06:53 nikolai ntpd[4784]: adjusting local clock by -1.884521s
Aug  4 03:08:28 nikolai ntpd[4784]: adjusting local clock by -1.819296s
Aug  4 03:12:46 nikolai ntpd[4784]: adjusting local clock by -1.712934s
Aug  4 03:15:48 nikolai ntpd[4784]: adjusting local clock by -1.607747s
Aug  4 03:19:31 nikolai ntpd[4784]: adjusting local clock by -1.535188s
Aug  4 03:21:05 nikolai ntpd[4784]: adjusting local clock by -1.439628s
Aug  4 03:24:56 nikolai ntpd[4784]: adjusting local clock by -1.376086s
Aug  4 03:29:12 nikolai ntpd[4784]: adjusting local clock by -1.271529s
Aug  4 03:32:20 nikolai ntpd[4784]: adjusting local clock by -1.162333s
Aug  4 03:36:08 nikolai ntpd[4784]: adjusting local clock by -1.023899s
Aug  4 03:40:02 nikolai ntpd[4784]: adjusting local clock by -0.902637s
Aug  4 03:43:43 nikolai ntpd[4784]: adjusting local clock by -0.789431s
Aug  4 03:47:35 nikolai ntpd[4784]: adjusting local clock by -0.679320s
Aug  4 03:50:45 nikolai ntpd[4784]: adjusting local clock by -0.605858s
Aug  4 03:53:31 nikolai ntpd[4784]: adjusting local clock by -0.529821s
Aug  4 03:56:33 nikolai ntpd[4784]: adjusting local clock by -0.429573s
Aug  4 03:59:46 nikolai ntpd[4784]: adjusting local clock by -0.312575s
Aug  4 04:03:14 nikolai ntpd[4784]: adjusting local clock by -0.232646s

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