The ntpd program is an operating-system daemon that sets and maintains a computer system's system time in synchronization with Internet-standard time servers. It is a complete implementation of the Network Time Protocol (NTP) version 4, but retains compatibility with versions 1, 2, and 3 as defined by RFC 1059, RFC 1119, and RFC 1305, respectively. ntpd performs most computations in 64-bit floating point arithmetic and uses 64-bit fixed point operations only when necessary to preserve the ultimate precision, about 232 picoseconds. While ordinary workstations and networks cannot achieve the ultimate precision as of 2015[update], future processors and networks may require it.
xntpd is the Network Time Protocol version three (1992) daemon software. The "x" was added to the name because the branch of code that eventually became NTPv3 was "experimental". The name of the software changed back to "ntpd" for version four[when?] because the inventor of NTP, Dave Mills, decided that something probably should not remain "experimental" for about twenty years in the absence of dramatic change.
ntpd uses a single configuration-file to run the daemon in server and/or client modes. The configuration file, usually named ntp.conf, is located in the /etc directory. Other important files include the drift file, which ntpd uses to correct for hardware-clock skew in the absence of a connection to a more accurate upstream time-server.
ntpd - Network Time Protocol (NTP) daemon Mills, D. L. The University of Delaware, USA. 2005. (Date Accessed: 19 August 2005)
External linksEdit
Official NTP Documentation for the current development release
NTP Community Support Information
NTP Development Collaboration
NTP Mailing Lists
NTP Software and Documentation Archive
NTP Documentation Archive for current development and all stable releases of the NTP codebase
OpenNTP manual pages
How To: CentOS / Red Hat Linux Configure an NTP Client And Server
Setting up NTP on Windows
Setting up on Linux/Windows/Macintosh the NTP Servers Pooling
October 27, 2023
ntpd, this, article, multiple, issues, please, help, improve, discuss, these, issues, talk, page, learn, when, remove, these, template, messages, this, article, includes, list, references, related, reading, external, links, sources, remain, unclear, because, l. This article has multiple issues Please help improve it or discuss these issues on the talk page Learn how and when to remove these template messages This article includes a list of references related reading or external links but its sources remain unclear because it lacks inline citations Please help to improve this article by introducing more precise citations July 2014 Learn how and when to remove this template message This article relies excessively on references to primary sources Please improve this article by adding secondary or tertiary sources Find sources Ntpd news newspapers books scholar JSTOR July 2014 Learn how and when to remove this template message Learn how and when to remove this template message The Network Time Protocol daemon ntpd is an operating system program that maintains the system time in synchronization with time servers using the Network Time Protocol NTP Contents 1 Description 2 Implementations 2 1 NTP implementations 2 2 Simple NTP SNTP implementations 3 See also 4 References 5 External linksDescription EditThe ntpd program is an operating system daemon that sets and maintains a computer system s system time in synchronization with Internet standard time servers It is a complete implementation of the Network Time Protocol NTP version 4 but retains compatibility with versions 1 2 and 3 as defined by RFC 1059 RFC 1119 and RFC 1305 respectively ntpd performs most computations in 64 bit floating point arithmetic and uses 64 bit fixed point operations only when necessary to preserve the ultimate precision about 232 picoseconds While ordinary workstations and networks cannot achieve the ultimate precision as of 2015 update future processors and networks may require it xntpd is the Network Time Protocol version three 1992 daemon software The x was added to the name because the branch of code that eventually became NTPv3 was experimental The name of the software changed back to ntpd for version four when because the inventor of NTP Dave Mills decided that something probably should not remain experimental for about twenty years in the absence of dramatic change ntpd uses a single configuration file to run the daemon in server and or client modes The configuration file usually named ntp conf is located in the etc directory Other important files include the drift file which ntpd uses to correct for hardware clock skew in the absence of a connection to a more accurate upstream time server Implementations EditFurther information Network Time Protocol Implementations NTP implementations Edit NTP RFC 5905 The NTP Reference Implementation from The NTP Project at the University of Delaware Windows Port of NTPD Free Windows port of The NTP Reference Implementation from http www ntp org with an easy to use installer NTPsec a hardened implementation derived from NTP Classic Dave Mills s original chrony chronyd implements the NTP protocol and can act as either a client or a server OpenNTPD A portable Simple NTPD implementation by the OpenBSD groupSimple NTP SNTP implementations Edit SNTP RFC 4330 clockspeed A simplest available and secure suite of NTP SNTP client clock skew eliminator and precise time synchronization server and client dntpd A simple client ntpd in DragonFly BSD ConnMan ConnMan contains an NTP implementation BusyBox since version 1 16 2 has included an SNTP client and server based on OpenNTP systemd timesyncd A Linux and systemd specific client implementation of SNTP See also Editrdate timedReferences Editntpd Network Time Protocol NTP daemon Mills D L The University of Delaware USA 2005 Date Accessed 19 August 2005 External links EditOfficial NTP Documentation for the current development release NTP Community Support Information NTP Development Collaboration NTP Mailing Lists NTP Software and Documentation Archive NTP Documentation Archive for current development and all stable releases of the NTP codebase OpenNTP manual pages How To CentOS Red Hat Linux Configure an NTP Client And Server Generic Linux notes Setting up NTP on Windows Setting up on Linux Windows Macintosh the NTP Servers Pooling Retrieved from https en wikipedia org w index php title Ntpd amp oldid 1162530479, wikipedia, wiki, book, books, library,
