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37052d159aSCy Schubert<body lang="en">
38052d159aSCy Schubert<h1 class="settitle" align="center">ntpd: Network Time Protocol (NTP) Daemon User&rsquo;s Manual</h1>
39052d159aSCy Schubert
40052d159aSCy Schubert
41052d159aSCy Schubert
42052d159aSCy Schubert
43052d159aSCy Schubert
44a466cc55SCy Schubert<span id="Top"></span><div class="header">
45052d159aSCy Schubert<p>
46052d159aSCy SchubertNext: <a href="#ntpd-Description" accesskey="n" rel="next">ntpd Description</a>, Previous: <a href="dir.html#Top" accesskey="p" rel="prev">(dir)</a>, Up: <a href="dir.html#Top" accesskey="u" rel="up">(dir)</a> &nbsp; </p>
47052d159aSCy Schubert</div>
48a466cc55SCy Schubert<span id="ntpd_003a-Network-Time-Protocol-_0028NTP_0029-Daemon-User-Manual"></span><h1 class="top">ntpd: Network Time Protocol (NTP) Daemon User Manual</h1>
492b15cb3dSCy Schubert
502b15cb3dSCy Schubert<p>The <code>ntpd</code> program is an operating system daemon that synchronizes the
512b15cb3dSCy Schubertsystem clock to remote NTP time servers or local reference clocks.
522b15cb3dSCy SchubertIt is a complete implementation of NTP version 4 defined by RFC-5905, but
532b15cb3dSCy Schubertalso retains compatible with version 3 defined by RFC-1305 and versions
542b15cb3dSCy Schubert1 and 2, defined by RFC-1059 and RFC-1119, respectively.
552b15cb3dSCy SchubertThe program can operate in any of several modes, including client/server,
562b15cb3dSCy Schubertsymmetric and broadcast modes, and with both symmetric-key and public-key
572b15cb3dSCy Schubertcryptography.
58052d159aSCy Schubert</p>
59*f5f40dd6SCy Schubert<p>This document applies to version 4.2.8p18 of <code>ntpd</code>.
60052d159aSCy Schubert</p>
61a466cc55SCy Schubert<span id="SEC_Overview"></span>
62052d159aSCy Schubert<h2 class="shortcontents-heading">Short Table of Contents</h2>
632b15cb3dSCy Schubert
64052d159aSCy Schubert<div class="shortcontents">
65052d159aSCy Schubert<ul class="no-bullet">
66a466cc55SCy Schubert<li><a id="stoc-Description" href="#toc-Description">1 Description</a></li>
672b15cb3dSCy Schubert</ul>
682b15cb3dSCy Schubert</div>
692b15cb3dSCy Schubert
70052d159aSCy Schubert
71052d159aSCy Schubert<table class="menu" border="0" cellspacing="0">
72a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-Description" accesskey="1">ntpd Description</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Description
73052d159aSCy Schubert</td></tr>
74a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-Invocation" accesskey="2">ntpd Invocation</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Invoking ntpd
75052d159aSCy Schubert</td></tr>
76a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#Usage" accesskey="3">Usage</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Usage
77052d159aSCy Schubert</td></tr>
78052d159aSCy Schubert</table>
79052d159aSCy Schubert
80052d159aSCy Schubert<hr>
81a466cc55SCy Schubert<span id="ntpd-Description"></span><div class="header">
82052d159aSCy Schubert<p>
83052d159aSCy SchubertNext: <a href="#ntpd-Invocation" accesskey="n" rel="next">ntpd Invocation</a>, Up: <a href="#Top" accesskey="u" rel="up">Top</a> &nbsp; </p>
84052d159aSCy Schubert</div>
85a466cc55SCy Schubert<span id="Description"></span><h2 class="chapter">1 Description</h2>
862b15cb3dSCy Schubert
872b15cb3dSCy Schubert<p>The <code>ntpd</code> program ordinarily requires
88052d159aSCy Schuberta configuration file described at &lsquo;ntp.conf&rsquo;.
892b15cb3dSCy SchubertThis configuration file contains configuration commands described on
902b15cb3dSCy Schubertthe pages listed above.
912b15cb3dSCy SchubertHowever a client can discover remote servers and configure them
922b15cb3dSCy Schubertautomatically.
932b15cb3dSCy SchubertThis makes it possible to deploy a fleet of workstations without
942b15cb3dSCy Schubertspecifying configuration details specific to the local environment.
95052d159aSCy Schubert</p>
962b15cb3dSCy Schubert<p>The <code>ntpd</code> program normally operates continuously while adjusting the
972b15cb3dSCy Schubertsystem time and frequency, but in some cases this might not be
982b15cb3dSCy Schubertpractical.
992b15cb3dSCy SchubertWith the <code>-q</code> option <code>ntpd</code> operates as in continuous mode, but
1002b15cb3dSCy Schubertexits just after setting the clock for the first time.
1012b15cb3dSCy SchubertMost applications will probably want to specify the <code>iburst</code>
1022b15cb3dSCy Schubertoption with the <code>server</code> command.
1032b15cb3dSCy SchubertWith this option an initial volley of messages is exchanged to
104052d159aSCy Schubertgroom the data and set the clock in about ten seconds&rsquo; time.
105052d159aSCy SchubertIf nothing is heard after a few minutes&rsquo; time,
1062b15cb3dSCy Schubertthe daemon times out and exits without setting the clock.
107052d159aSCy Schubert</p>
108052d159aSCy Schubert<table class="menu" border="0" cellspacing="0">
109a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-Invocation" accesskey="1">Invoking ntpd</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">
110052d159aSCy Schubert</td></tr>
111a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#Usage" accesskey="2">Usage</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">
112052d159aSCy Schubert</td></tr>
113052d159aSCy Schubert</table>
1142b15cb3dSCy Schubert
115052d159aSCy Schubert<hr>
116a466cc55SCy Schubert<span id="ntpd-Invocation"></span><div class="header">
117052d159aSCy Schubert<p>
118052d159aSCy SchubertNext: <a href="#Usage" accesskey="n" rel="next">Usage</a>, Previous: <a href="#ntpd-Description" accesskey="p" rel="prev">ntpd Description</a>, Up: <a href="#ntpd-Description" accesskey="u" rel="up">ntpd Description</a> &nbsp; </p>
1192b15cb3dSCy Schubert</div>
120a466cc55SCy Schubert<span id="Invoking-ntpd"></span><h3 class="section">1.1 Invoking ntpd</h3>
121a466cc55SCy Schubert<span id="index-ntpd"></span>
122a466cc55SCy Schubert<span id="index-NTP-daemon-program"></span>
1232b15cb3dSCy Schubert
1242b15cb3dSCy Schubert
1252b15cb3dSCy Schubert
1262b15cb3dSCy Schubert<p>The
1272b15cb3dSCy Schubert<code>ntpd</code>
1282b15cb3dSCy Schubertutility is an operating system daemon which sets
1292b15cb3dSCy Schubertand maintains the system time of day in synchronism with Internet
1302b15cb3dSCy Schubertstandard time servers.
1312b15cb3dSCy SchubertIt is a complete implementation of the
1322b15cb3dSCy SchubertNetwork Time Protocol (NTP) version 4, as defined by RFC-5905,
1332b15cb3dSCy Schubertbut also retains compatibility with
1342b15cb3dSCy Schubertversion 3, as defined by RFC-1305, and versions 1
1352b15cb3dSCy Schubertand 2, as defined by RFC-1059 and RFC-1119, respectively.
136052d159aSCy Schubert</p>
1372b15cb3dSCy Schubert<p>The
1382b15cb3dSCy Schubert<code>ntpd</code>
1392b15cb3dSCy Schubertutility does most computations in 64-bit floating point
1402b15cb3dSCy Schubertarithmetic and does relatively clumsy 64-bit fixed point operations
1412b15cb3dSCy Schubertonly when necessary to preserve the ultimate precision, about 232
1422b15cb3dSCy Schubertpicoseconds.
1432b15cb3dSCy SchubertWhile the ultimate precision is not achievable with
1442b15cb3dSCy Schubertordinary workstations and networks of today, it may be required
1452b15cb3dSCy Schubertwith future gigahertz CPU clocks and gigabit LANs.
146052d159aSCy Schubert</p>
1472b15cb3dSCy Schubert<p>Ordinarily,
1482b15cb3dSCy Schubert<code>ntpd</code>
1492b15cb3dSCy Schubertreads the
1502b15cb3dSCy Schubert<code>ntp.conf(5)</code>
1512b15cb3dSCy Schubertconfiguration file at startup time in order to determine the
1522b15cb3dSCy Schubertsynchronization sources and operating modes.
1532b15cb3dSCy SchubertIt is also possible to
1542b15cb3dSCy Schubertspecify a working, although limited, configuration entirely on the
1552b15cb3dSCy Schubertcommand line, obviating the need for a configuration file.
1562b15cb3dSCy SchubertThis may
1572b15cb3dSCy Schubertbe particularly useful when the local host is to be configured as a
1582b15cb3dSCy Schubertbroadcast/multicast client, with all peers being determined by
1592b15cb3dSCy Schubertlistening to broadcasts at run time.
160052d159aSCy Schubert</p>
1612b15cb3dSCy Schubert<p>If NetInfo support is built into
1622b15cb3dSCy Schubert<code>ntpd</code>
1632b15cb3dSCy Schubertthen
1642b15cb3dSCy Schubert<code>ntpd</code>
1652b15cb3dSCy Schubertwill attempt to read its configuration from the
1662b15cb3dSCy SchubertNetInfo if the default
1672b15cb3dSCy Schubert<code>ntp.conf(5)</code>
1682b15cb3dSCy Schubertfile cannot be read and no file is
1692b15cb3dSCy Schubertspecified by the
1702b15cb3dSCy Schubert<code>-c</code>
1712b15cb3dSCy Schubertoption.
172052d159aSCy Schubert</p>
1732b15cb3dSCy Schubert<p>Various internal
1742b15cb3dSCy Schubert<code>ntpd</code>
1752b15cb3dSCy Schubertvariables can be displayed and
1762b15cb3dSCy Schubertconfiguration options altered while the
1772b15cb3dSCy Schubert<code>ntpd</code>
1782b15cb3dSCy Schubertis running
1792b15cb3dSCy Schubertusing the
1802b15cb3dSCy Schubert<code>ntpq(1ntpqmdoc)</code>
1812b15cb3dSCy Schubertand
1822b15cb3dSCy Schubert<code>ntpdc(1ntpdcmdoc)</code>
1832b15cb3dSCy Schubertutility programs.
184052d159aSCy Schubert</p>
1852b15cb3dSCy Schubert<p>When
1862b15cb3dSCy Schubert<code>ntpd</code>
1872b15cb3dSCy Schubertstarts it looks at the value of
1882b15cb3dSCy Schubert<code>umask(2)</code>,
1892b15cb3dSCy Schubertand if zero
1902b15cb3dSCy Schubert<code>ntpd</code>
1912b15cb3dSCy Schubertwill set the
1922b15cb3dSCy Schubert<code>umask(2)</code>
1932b15cb3dSCy Schubertto 022.
194052d159aSCy Schubert</p>
1952b15cb3dSCy Schubert<p>This section was generated by <strong>AutoGen</strong>,
1962b15cb3dSCy Schubertusing the <code>agtexi-cmd</code> template and the option descriptions for the <code>ntpd</code> program.
1972b15cb3dSCy SchubertThis software is released under the NTP license, &lt;http://ntp.org/license&gt;.
198052d159aSCy Schubert</p>
199052d159aSCy Schubert<table class="menu" border="0" cellspacing="0">
200a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-usage" accesskey="1">ntpd usage</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">ntpd help/usage (<samp>--help</samp>)
201052d159aSCy Schubert</td></tr>
202a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-ipv4" accesskey="2">ntpd ipv4</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">ipv4 option (-4)
203052d159aSCy Schubert</td></tr>
204a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-ipv6" accesskey="3">ntpd ipv6</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">ipv6 option (-6)
205052d159aSCy Schubert</td></tr>
206a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-authreq" accesskey="4">ntpd authreq</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">authreq option (-a)
207052d159aSCy Schubert</td></tr>
208a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-authnoreq" accesskey="5">ntpd authnoreq</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">authnoreq option (-A)
209052d159aSCy Schubert</td></tr>
210a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-configfile" accesskey="6">ntpd configfile</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">configfile option (-c)
211052d159aSCy Schubert</td></tr>
212a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-driftfile" accesskey="7">ntpd driftfile</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">driftfile option (-f)
213052d159aSCy Schubert</td></tr>
214a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-panicgate" accesskey="8">ntpd panicgate</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">panicgate option (-g)
215052d159aSCy Schubert</td></tr>
216a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-force_002dstep_002donce" accesskey="9">ntpd force-step-once</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">force-step-once option (-G)
217052d159aSCy Schubert</td></tr>
218a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-jaildir">ntpd jaildir</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">jaildir option (-i)
219052d159aSCy Schubert</td></tr>
220a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-interface">ntpd interface</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">interface option (-I)
221052d159aSCy Schubert</td></tr>
222a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-keyfile">ntpd keyfile</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">keyfile option (-k)
223052d159aSCy Schubert</td></tr>
224a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-logfile">ntpd logfile</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">logfile option (-l)
225052d159aSCy Schubert</td></tr>
226a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-novirtualips">ntpd novirtualips</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">novirtualips option (-L)
227052d159aSCy Schubert</td></tr>
228a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-modifymmtimer">ntpd modifymmtimer</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">modifymmtimer option (-M)
229052d159aSCy Schubert</td></tr>
230a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-nice">ntpd nice</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">nice option (-N)
231052d159aSCy Schubert</td></tr>
232a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-pidfile">ntpd pidfile</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">pidfile option (-p)
233052d159aSCy Schubert</td></tr>
234a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-priority">ntpd priority</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">priority option (-P)
235052d159aSCy Schubert</td></tr>
236a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-quit">ntpd quit</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">quit option (-q)
237052d159aSCy Schubert</td></tr>
238a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-propagationdelay">ntpd propagationdelay</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">propagationdelay option (-r)
239052d159aSCy Schubert</td></tr>
240a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-saveconfigquit">ntpd saveconfigquit</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">saveconfigquit option
241052d159aSCy Schubert</td></tr>
242a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-statsdir">ntpd statsdir</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">statsdir option (-s)
243052d159aSCy Schubert</td></tr>
244a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-trustedkey">ntpd trustedkey</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">trustedkey option (-t)
245052d159aSCy Schubert</td></tr>
246a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-user">ntpd user</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">user option (-u)
247052d159aSCy Schubert</td></tr>
248a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-updateinterval">ntpd updateinterval</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">updateinterval option (-U)
249052d159aSCy Schubert</td></tr>
250a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-wait_002dsync">ntpd wait-sync</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">wait-sync option (-w)
251052d159aSCy Schubert</td></tr>
252a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-slew">ntpd slew</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">slew option (-x)
253052d159aSCy Schubert</td></tr>
254a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-usepcc">ntpd usepcc</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">usepcc option
255052d159aSCy Schubert</td></tr>
256a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-pccfreq">ntpd pccfreq</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">pccfreq option
257052d159aSCy Schubert</td></tr>
258a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-mdns">ntpd mdns</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">mdns option (-m)
259052d159aSCy Schubert</td></tr>
260a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-config">ntpd config</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">presetting/configuring ntpd
261052d159aSCy Schubert</td></tr>
262a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-exit-status">ntpd exit status</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">exit status
263052d159aSCy Schubert</td></tr>
264a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-Usage">ntpd Usage</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Usage
265052d159aSCy Schubert</td></tr>
266a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-Files">ntpd Files</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Files
267052d159aSCy Schubert</td></tr>
268a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-See-Also">ntpd See Also</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">See Also
269052d159aSCy Schubert</td></tr>
270a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-Bugs">ntpd Bugs</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Bugs
271052d159aSCy Schubert</td></tr>
272a466cc55SCy Schubert<tr><td align="left" valign="top">&bull; <a href="#ntpd-Notes">ntpd Notes</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Notes
273052d159aSCy Schubert</td></tr>
274052d159aSCy Schubert</table>
2752b15cb3dSCy Schubert
276052d159aSCy Schubert<hr>
277a466cc55SCy Schubert<span id="ntpd-usage"></span><div class="header">
278052d159aSCy Schubert<p>
279052d159aSCy SchubertNext: <a href="#ntpd-ipv4" accesskey="n" rel="next">ntpd ipv4</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
2802b15cb3dSCy Schubert</div>
281a466cc55SCy Schubert<span id="ntpd-help_002fusage-_0028_002d_002dhelp_0029"></span><h4 class="subsection">1.1.1 ntpd help/usage (<samp>--help</samp>)</h4>
282a466cc55SCy Schubert<span id="index-ntpd-help"></span>
2832b15cb3dSCy Schubert
284052d159aSCy Schubert<p>This is the automatically generated usage text for ntpd.
285052d159aSCy Schubert</p>
2862b15cb3dSCy Schubert<p>The text printed is the same whether selected with the <code>help</code> option
287052d159aSCy Schubert(<samp>--help</samp>) or the <code>more-help</code> option (<samp>--more-help</samp>).  <code>more-help</code> will print
2882b15cb3dSCy Schubertthe usage text by passing it through a pager program.
2892b15cb3dSCy Schubert<code>more-help</code> is disabled on platforms without a working
2902b15cb3dSCy Schubert<code>fork(2)</code> function.  The <code>PAGER</code> environment variable is
291052d159aSCy Schubertused to select the program, defaulting to <samp>more</samp>.  Both will exit
2922b15cb3dSCy Schubertwith a status code of 0.
293052d159aSCy Schubert</p>
294052d159aSCy Schubert<div class="example">
295*f5f40dd6SCy Schubert<pre class="example">ntpd - NTP daemon program - Ver. 4.2.8p18
2962b15cb3dSCy SchubertUsage:  ntpd [ -&lt;flag&gt; [&lt;val&gt;] | --&lt;name&gt;[{=| }&lt;val&gt;] ]... \
2972b15cb3dSCy Schubert                [ &lt;server1&gt; ... &lt;serverN&gt; ]
2982b15cb3dSCy Schubert  Flg Arg Option-Name    Description
2992b15cb3dSCy Schubert   -4 no  ipv4           Force IPv4 DNS name resolution
3002b15cb3dSCy Schubert                                - prohibits the option 'ipv6'
3012b15cb3dSCy Schubert   -6 no  ipv6           Force IPv6 DNS name resolution
3022b15cb3dSCy Schubert                                - prohibits the option 'ipv4'
3032b15cb3dSCy Schubert   -a no  authreq        Require crypto authentication
3042b15cb3dSCy Schubert                                - prohibits the option 'authnoreq'
3052b15cb3dSCy Schubert   -A no  authnoreq      Do not require crypto authentication
3062b15cb3dSCy Schubert                                - prohibits the option 'authreq'
3072b15cb3dSCy Schubert   -b no  bcastsync      Allow us to sync to broadcast servers
3082b15cb3dSCy Schubert   -c Str configfile     configuration file name
3092b15cb3dSCy Schubert   -d no  debug-level    Increase debug verbosity level
3102b15cb3dSCy Schubert                                - may appear multiple times
3112b15cb3dSCy Schubert   -D Num set-debug-level Set the debug verbosity level
3122b15cb3dSCy Schubert                                - may appear multiple times
3132b15cb3dSCy Schubert   -f Str driftfile      frequency drift file name
3142b15cb3dSCy Schubert   -g no  panicgate      Allow the first adjustment to be Big
3152b15cb3dSCy Schubert                                - may appear multiple times
316a25439b6SCy Schubert   -G no  force-step-once Step any initial offset correction.
3172d4e511cSCy Schubert   -i --- jaildir        built without --enable-clockctl or --enable-linuxcaps or --enable-solarisprivs
3182b15cb3dSCy Schubert   -I Str interface      Listen on an interface name or address
3192b15cb3dSCy Schubert                                - may appear multiple times
3202b15cb3dSCy Schubert   -k Str keyfile        path to symmetric keys
3212b15cb3dSCy Schubert   -l Str logfile        path to the log file
3222b15cb3dSCy Schubert   -L no  novirtualips   Do not listen to virtual interfaces
3232b15cb3dSCy Schubert   -n no  nofork         Do not fork
3242b15cb3dSCy Schubert                                - prohibits the option 'wait-sync'
3252b15cb3dSCy Schubert   -N no  nice           Run at high priority
3262b15cb3dSCy Schubert   -p Str pidfile        path to the PID file
3272b15cb3dSCy Schubert   -P Num priority       Process priority
3282b15cb3dSCy Schubert   -q no  quit           Set the time and quit
3292b15cb3dSCy Schubert                                - prohibits these options:
3302b15cb3dSCy Schubert                                saveconfigquit
3312b15cb3dSCy Schubert                                wait-sync
3322b15cb3dSCy Schubert   -r Str propagationdelay Broadcast/propagation delay
3332b15cb3dSCy Schubert      Str saveconfigquit Save parsed configuration and quit
3342b15cb3dSCy Schubert                                - prohibits these options:
3352b15cb3dSCy Schubert                                quit
3362b15cb3dSCy Schubert                                wait-sync
3372b15cb3dSCy Schubert   -s Str statsdir       Statistics file location
3382b15cb3dSCy Schubert   -t Str trustedkey     Trusted key number
3392b15cb3dSCy Schubert                                - may appear multiple times
3402d4e511cSCy Schubert   -u --- user           built without --enable-clockctl or --enable-linuxcaps or --enable-solarisprivs
3412b15cb3dSCy Schubert   -U Num updateinterval interval in seconds between scans for new or dropped interfaces
3422b15cb3dSCy Schubert      Str var            make ARG an ntp variable (RW)
3432b15cb3dSCy Schubert                                - may appear multiple times
3442b15cb3dSCy Schubert      Str dvar           make ARG an ntp variable (RW|DEF)
3452b15cb3dSCy Schubert                                - may appear multiple times
3462b15cb3dSCy Schubert   -w Num wait-sync      Seconds to wait for first clock sync
3472b15cb3dSCy Schubert                                - prohibits these options:
3482b15cb3dSCy Schubert                                nofork
3492b15cb3dSCy Schubert                                quit
3502b15cb3dSCy Schubert                                saveconfigquit
3512b15cb3dSCy Schubert   -x no  slew           Slew up to 600 seconds
3522b15cb3dSCy Schubert      opt version        output version information and exit
3532b15cb3dSCy Schubert   -? no  help           display extended usage information and exit
3542b15cb3dSCy Schubert   -! no  more-help      extended usage information passed thru pager
3552b15cb3dSCy Schubert
3562b15cb3dSCy SchubertOptions are specified by doubled hyphens and their name or by a single
3572b15cb3dSCy Schuberthyphen and the flag character.
3582b15cb3dSCy Schubert
3592b15cb3dSCy Schubert
3602b15cb3dSCy SchubertThe following option preset mechanisms are supported:
3612b15cb3dSCy Schubert - examining environment variables named NTPD_*
3622b15cb3dSCy Schubert
363a466cc55SCy SchubertPlease send bug reports to:  &lt;https://bugs.ntp.org, bugs@ntp.org&gt;
364052d159aSCy Schubert</pre></div>
365052d159aSCy Schubert
366052d159aSCy Schubert<hr>
367a466cc55SCy Schubert<span id="ntpd-ipv4"></span><div class="header">
368052d159aSCy Schubert<p>
369052d159aSCy SchubertNext: <a href="#ntpd-ipv6" accesskey="n" rel="next">ntpd ipv6</a>, Previous: <a href="#ntpd-usage" accesskey="p" rel="prev">ntpd usage</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
3702b15cb3dSCy Schubert</div>
371a466cc55SCy Schubert<span id="ipv4-option-_0028_002d4_0029"></span><h4 class="subsection">1.1.2 ipv4 option (-4)</h4>
372a466cc55SCy Schubert<span id="index-ntpd_002dipv4"></span>
3732b15cb3dSCy Schubert
374052d159aSCy Schubert<p>This is the &ldquo;force ipv4 dns name resolution&rdquo; option.
375052d159aSCy Schubert</p>
376052d159aSCy Schubert<p>This option has some usage constraints.  It:
377052d159aSCy Schubert</p><ul>
3782b15cb3dSCy Schubert<li> must not appear in combination with any of the following options:
3792b15cb3dSCy Schubertipv6.
380052d159aSCy Schubert</li></ul>
3812b15cb3dSCy Schubert
3822b15cb3dSCy Schubert<p>Force DNS resolution of following host names on the command line
3832b15cb3dSCy Schubertto the IPv4 namespace.
384052d159aSCy Schubert</p><hr>
385a466cc55SCy Schubert<span id="ntpd-ipv6"></span><div class="header">
386052d159aSCy Schubert<p>
387052d159aSCy SchubertNext: <a href="#ntpd-authreq" accesskey="n" rel="next">ntpd authreq</a>, Previous: <a href="#ntpd-ipv4" accesskey="p" rel="prev">ntpd ipv4</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
3882b15cb3dSCy Schubert</div>
389a466cc55SCy Schubert<span id="ipv6-option-_0028_002d6_0029"></span><h4 class="subsection">1.1.3 ipv6 option (-6)</h4>
390a466cc55SCy Schubert<span id="index-ntpd_002dipv6"></span>
3912b15cb3dSCy Schubert
392052d159aSCy Schubert<p>This is the &ldquo;force ipv6 dns name resolution&rdquo; option.
393052d159aSCy Schubert</p>
394052d159aSCy Schubert<p>This option has some usage constraints.  It:
395052d159aSCy Schubert</p><ul>
3962b15cb3dSCy Schubert<li> must not appear in combination with any of the following options:
3972b15cb3dSCy Schubertipv4.
398052d159aSCy Schubert</li></ul>
3992b15cb3dSCy Schubert
4002b15cb3dSCy Schubert<p>Force DNS resolution of following host names on the command line
4012b15cb3dSCy Schubertto the IPv6 namespace.
402052d159aSCy Schubert</p><hr>
403a466cc55SCy Schubert<span id="ntpd-authreq"></span><div class="header">
404052d159aSCy Schubert<p>
405052d159aSCy SchubertNext: <a href="#ntpd-authnoreq" accesskey="n" rel="next">ntpd authnoreq</a>, Previous: <a href="#ntpd-ipv6" accesskey="p" rel="prev">ntpd ipv6</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
4062b15cb3dSCy Schubert</div>
407a466cc55SCy Schubert<span id="authreq-option-_0028_002da_0029"></span><h4 class="subsection">1.1.4 authreq option (-a)</h4>
408a466cc55SCy Schubert<span id="index-ntpd_002dauthreq"></span>
4092b15cb3dSCy Schubert
410052d159aSCy Schubert<p>This is the &ldquo;require crypto authentication&rdquo; option.
411052d159aSCy Schubert</p>
412052d159aSCy Schubert<p>This option has some usage constraints.  It:
413052d159aSCy Schubert</p><ul>
4142b15cb3dSCy Schubert<li> must not appear in combination with any of the following options:
4152b15cb3dSCy Schubertauthnoreq.
416052d159aSCy Schubert</li></ul>
4172b15cb3dSCy Schubert
4182b15cb3dSCy Schubert<p>Require cryptographic authentication for broadcast client,
4192b15cb3dSCy Schubertmulticast client and symmetric passive associations.
4202b15cb3dSCy SchubertThis is the default.
421052d159aSCy Schubert</p><hr>
422a466cc55SCy Schubert<span id="ntpd-authnoreq"></span><div class="header">
423052d159aSCy Schubert<p>
424052d159aSCy SchubertNext: <a href="#ntpd-configfile" accesskey="n" rel="next">ntpd configfile</a>, Previous: <a href="#ntpd-authreq" accesskey="p" rel="prev">ntpd authreq</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
4252b15cb3dSCy Schubert</div>
426a466cc55SCy Schubert<span id="authnoreq-option-_0028_002dA_0029"></span><h4 class="subsection">1.1.5 authnoreq option (-A)</h4>
427a466cc55SCy Schubert<span id="index-ntpd_002dauthnoreq"></span>
4282b15cb3dSCy Schubert
429052d159aSCy Schubert<p>This is the &ldquo;do not require crypto authentication&rdquo; option.
430052d159aSCy Schubert</p>
431052d159aSCy Schubert<p>This option has some usage constraints.  It:
432052d159aSCy Schubert</p><ul>
4332b15cb3dSCy Schubert<li> must not appear in combination with any of the following options:
4342b15cb3dSCy Schubertauthreq.
435052d159aSCy Schubert</li></ul>
4362b15cb3dSCy Schubert
4372b15cb3dSCy Schubert<p>Do not require cryptographic authentication for broadcast client,
4382b15cb3dSCy Schubertmulticast client and symmetric passive associations.
4392b15cb3dSCy SchubertThis is almost never a good idea.
440052d159aSCy Schubert</p><hr>
441a466cc55SCy Schubert<span id="ntpd-configfile"></span><div class="header">
442052d159aSCy Schubert<p>
443052d159aSCy SchubertNext: <a href="#ntpd-driftfile" accesskey="n" rel="next">ntpd driftfile</a>, Previous: <a href="#ntpd-authnoreq" accesskey="p" rel="prev">ntpd authnoreq</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
4442b15cb3dSCy Schubert</div>
445a466cc55SCy Schubert<span id="configfile-option-_0028_002dc_0029"></span><h4 class="subsection">1.1.6 configfile option (-c)</h4>
446a466cc55SCy Schubert<span id="index-ntpd_002dconfigfile"></span>
4472b15cb3dSCy Schubert
448052d159aSCy Schubert<p>This is the &ldquo;configuration file name&rdquo; option.
4492b15cb3dSCy SchubertThis option takes a string argument.
4502b15cb3dSCy SchubertThe name and path of the configuration file,
451052d159aSCy Schubert<samp>/etc/ntp.conf</samp>
4522b15cb3dSCy Schubertby default.
453052d159aSCy Schubert</p><hr>
454a466cc55SCy Schubert<span id="ntpd-driftfile"></span><div class="header">
455052d159aSCy Schubert<p>
456052d159aSCy SchubertNext: <a href="#ntpd-panicgate" accesskey="n" rel="next">ntpd panicgate</a>, Previous: <a href="#ntpd-configfile" accesskey="p" rel="prev">ntpd configfile</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
4572b15cb3dSCy Schubert</div>
458a466cc55SCy Schubert<span id="driftfile-option-_0028_002df_0029"></span><h4 class="subsection">1.1.7 driftfile option (-f)</h4>
459a466cc55SCy Schubert<span id="index-ntpd_002ddriftfile"></span>
4602b15cb3dSCy Schubert
461052d159aSCy Schubert<p>This is the &ldquo;frequency drift file name&rdquo; option.
4622b15cb3dSCy SchubertThis option takes a string argument.
4632b15cb3dSCy SchubertThe name and path of the frequency file,
464052d159aSCy Schubert<samp>/etc/ntp.drift</samp>
4652b15cb3dSCy Schubertby default.
4662b15cb3dSCy SchubertThis is the same operation as the
4672b15cb3dSCy Schubert<code>driftfile</code> <kbd>driftfile</kbd>
4682b15cb3dSCy Schubertconfiguration specification in the
469052d159aSCy Schubert<samp>/etc/ntp.conf</samp>
4702b15cb3dSCy Schubertfile.
471052d159aSCy Schubert</p><hr>
472a466cc55SCy Schubert<span id="ntpd-panicgate"></span><div class="header">
473052d159aSCy Schubert<p>
474052d159aSCy SchubertNext: <a href="#ntpd-force_002dstep_002donce" accesskey="n" rel="next">ntpd force-step-once</a>, Previous: <a href="#ntpd-driftfile" accesskey="p" rel="prev">ntpd driftfile</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
4752b15cb3dSCy Schubert</div>
476a466cc55SCy Schubert<span id="panicgate-option-_0028_002dg_0029"></span><h4 class="subsection">1.1.8 panicgate option (-g)</h4>
477a466cc55SCy Schubert<span id="index-ntpd_002dpanicgate"></span>
4782b15cb3dSCy Schubert
479052d159aSCy Schubert<p>This is the &ldquo;allow the first adjustment to be big&rdquo; option.
480052d159aSCy Schubert</p>
481052d159aSCy Schubert<p>This option has some usage constraints.  It:
482052d159aSCy Schubert</p><ul>
4832b15cb3dSCy Schubert<li> may appear an unlimited number of times.
484052d159aSCy Schubert</li></ul>
4852b15cb3dSCy Schubert
4862b15cb3dSCy Schubert<p>Normally,
4872b15cb3dSCy Schubert<code>ntpd</code>
4882b15cb3dSCy Schubertexits with a message to the system log if the offset exceeds the panic threshold, which is 1000 s by default. This option allows the time to be set to any value without restriction; however, this can happen only once. If the threshold is exceeded after that,
4892b15cb3dSCy Schubert<code>ntpd</code>
4902b15cb3dSCy Schubertwill exit with a message to the system log. This option can be used with the
4912b15cb3dSCy Schubert<code>-q</code>
4922b15cb3dSCy Schubertand
4932b15cb3dSCy Schubert<code>-x</code>
4942b15cb3dSCy Schubertoptions.
4952b15cb3dSCy SchubertSee the
4962b15cb3dSCy Schubert<code>tinker</code>
4972b15cb3dSCy Schubertconfiguration file directive for other options.
498052d159aSCy Schubert</p><hr>
499a466cc55SCy Schubert<span id="ntpd-force_002dstep_002donce"></span><div class="header">
500052d159aSCy Schubert<p>
501052d159aSCy SchubertNext: <a href="#ntpd-jaildir" accesskey="n" rel="next">ntpd jaildir</a>, Previous: <a href="#ntpd-panicgate" accesskey="p" rel="prev">ntpd panicgate</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
5022b15cb3dSCy Schubert</div>
503a466cc55SCy Schubert<span id="force_002dstep_002donce-option-_0028_002dG_0029"></span><h4 class="subsection">1.1.9 force-step-once option (-G)</h4>
504a466cc55SCy Schubert<span id="index-ntpd_002dforce_002dstep_002donce"></span>
5052b15cb3dSCy Schubert
506052d159aSCy Schubert<p>This is the &ldquo;step any initial offset correction.&rdquo; option.
507a25439b6SCy SchubertNormally,
508a25439b6SCy Schubert<code>ntpd</code>
509a25439b6SCy Schubertsteps the time if the time offset exceeds the step threshold,
510a25439b6SCy Schubertwhich is 128 ms by default, and otherwise slews the time.
511a25439b6SCy SchubertThis option forces the initial offset correction to be stepped,
512a25439b6SCy Schubertso the highest time accuracy can be achieved quickly.
513a25439b6SCy SchubertHowever, this may also cause the time to be stepped back
514a25439b6SCy Schubertso this option must not be used if
515a25439b6SCy Schubertapplications requiring monotonic time are running.
516a25439b6SCy SchubertSee the <code>tinker</code> configuration file directive for other options.
517052d159aSCy Schubert</p><hr>
518a466cc55SCy Schubert<span id="ntpd-jaildir"></span><div class="header">
519052d159aSCy Schubert<p>
520052d159aSCy SchubertNext: <a href="#ntpd-interface" accesskey="n" rel="next">ntpd interface</a>, Previous: <a href="#ntpd-force_002dstep_002donce" accesskey="p" rel="prev">ntpd force-step-once</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
521a25439b6SCy Schubert</div>
522a466cc55SCy Schubert<span id="jaildir-option-_0028_002di_0029"></span><h4 class="subsection">1.1.10 jaildir option (-i)</h4>
523a466cc55SCy Schubert<span id="index-ntpd_002djaildir"></span>
524a25439b6SCy Schubert
525052d159aSCy Schubert<p>This is the &ldquo;jail directory&rdquo; option.
5262b15cb3dSCy SchubertThis option takes a string argument.
527052d159aSCy Schubert</p>
528052d159aSCy Schubert<p>This option has some usage constraints.  It:
529052d159aSCy Schubert</p><ul>
5302b15cb3dSCy Schubert<li> must be compiled in by defining <code>HAVE_DROPROOT</code> during the compilation.
531052d159aSCy Schubert</li></ul>
5322b15cb3dSCy Schubert
5332b15cb3dSCy Schubert<p>Chroot the server to the directory
5342b15cb3dSCy Schubert<kbd>jaildir</kbd>
5352b15cb3dSCy Schubert.
5362b15cb3dSCy SchubertThis option also implies that the server attempts to drop root privileges at startup.
5372b15cb3dSCy SchubertYou may need to also specify a
5382b15cb3dSCy Schubert<code>-u</code>
5392b15cb3dSCy Schubertoption.
5402b15cb3dSCy SchubertThis option is only available if the OS supports adjusting the clock
5412b15cb3dSCy Schubertwithout full root privileges.
5422b15cb3dSCy SchubertThis option is supported under NetBSD (configure with
5432b15cb3dSCy Schubert<code>--enable-clockctl</code>) or Linux (configure with
5442b15cb3dSCy Schubert<code>--enable-linuxcaps</code>) or Solaris (configure with <code>--enable-solarisprivs</code>).
545052d159aSCy Schubert</p><hr>
546a466cc55SCy Schubert<span id="ntpd-interface"></span><div class="header">
547052d159aSCy Schubert<p>
548052d159aSCy SchubertNext: <a href="#ntpd-keyfile" accesskey="n" rel="next">ntpd keyfile</a>, Previous: <a href="#ntpd-jaildir" accesskey="p" rel="prev">ntpd jaildir</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
5492b15cb3dSCy Schubert</div>
550a466cc55SCy Schubert<span id="interface-option-_0028_002dI_0029"></span><h4 class="subsection">1.1.11 interface option (-I)</h4>
551a466cc55SCy Schubert<span id="index-ntpd_002dinterface"></span>
5522b15cb3dSCy Schubert
553052d159aSCy Schubert<p>This is the &ldquo;listen on an interface name or address&rdquo; option.
554052d159aSCy SchubertThis option takes a string argument <samp>iface</samp>.
555052d159aSCy Schubert</p>
556052d159aSCy Schubert<p>This option has some usage constraints.  It:
557052d159aSCy Schubert</p><ul>
5582b15cb3dSCy Schubert<li> may appear an unlimited number of times.
559052d159aSCy Schubert</li></ul>
5602b15cb3dSCy Schubert
5612b15cb3dSCy Schubert<p>Open the network address given, or all the addresses associated with the
5622b15cb3dSCy Schubertgiven interface name.  This option may appear multiple times.  This option
5632b15cb3dSCy Schubertalso implies not opening other addresses, except wildcard and localhost.
5642b15cb3dSCy SchubertThis option is deprecated. Please consider using the configuration file
5652b15cb3dSCy Schubert<code>interface</code> command, which is more versatile.
566052d159aSCy Schubert</p><hr>
567a466cc55SCy Schubert<span id="ntpd-keyfile"></span><div class="header">
568052d159aSCy Schubert<p>
569052d159aSCy SchubertNext: <a href="#ntpd-logfile" accesskey="n" rel="next">ntpd logfile</a>, Previous: <a href="#ntpd-interface" accesskey="p" rel="prev">ntpd interface</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
5702b15cb3dSCy Schubert</div>
571a466cc55SCy Schubert<span id="keyfile-option-_0028_002dk_0029"></span><h4 class="subsection">1.1.12 keyfile option (-k)</h4>
572a466cc55SCy Schubert<span id="index-ntpd_002dkeyfile"></span>
5732b15cb3dSCy Schubert
574052d159aSCy Schubert<p>This is the &ldquo;path to symmetric keys&rdquo; option.
5752b15cb3dSCy SchubertThis option takes a string argument.
5762b15cb3dSCy SchubertSpecify the name and path of the symmetric key file.
577052d159aSCy Schubert<samp>/etc/ntp.keys</samp>
5782b15cb3dSCy Schubertis the default.
5792b15cb3dSCy SchubertThis is the same operation as the
5802b15cb3dSCy Schubert<code>keys</code> <kbd>keyfile</kbd>
5812b15cb3dSCy Schubertconfiguration file directive.
582052d159aSCy Schubert</p><hr>
583a466cc55SCy Schubert<span id="ntpd-logfile"></span><div class="header">
584052d159aSCy Schubert<p>
585052d159aSCy SchubertNext: <a href="#ntpd-novirtualips" accesskey="n" rel="next">ntpd novirtualips</a>, Previous: <a href="#ntpd-keyfile" accesskey="p" rel="prev">ntpd keyfile</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
5862b15cb3dSCy Schubert</div>
587a466cc55SCy Schubert<span id="logfile-option-_0028_002dl_0029"></span><h4 class="subsection">1.1.13 logfile option (-l)</h4>
588a466cc55SCy Schubert<span id="index-ntpd_002dlogfile"></span>
5892b15cb3dSCy Schubert
590052d159aSCy Schubert<p>This is the &ldquo;path to the log file&rdquo; option.
5912b15cb3dSCy SchubertThis option takes a string argument.
5922b15cb3dSCy SchubertSpecify the name and path of the log file.
5932b15cb3dSCy SchubertThe default is the system log file.
5942b15cb3dSCy SchubertThis is the same operation as the
5952b15cb3dSCy Schubert<code>logfile</code> <kbd>logfile</kbd>
5962b15cb3dSCy Schubertconfiguration file directive.
597052d159aSCy Schubert</p><hr>
598a466cc55SCy Schubert<span id="ntpd-novirtualips"></span><div class="header">
599052d159aSCy Schubert<p>
600052d159aSCy SchubertNext: <a href="#ntpd-modifymmtimer" accesskey="n" rel="next">ntpd modifymmtimer</a>, Previous: <a href="#ntpd-logfile" accesskey="p" rel="prev">ntpd logfile</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
6012b15cb3dSCy Schubert</div>
602a466cc55SCy Schubert<span id="novirtualips-option-_0028_002dL_0029"></span><h4 class="subsection">1.1.14 novirtualips option (-L)</h4>
603a466cc55SCy Schubert<span id="index-ntpd_002dnovirtualips"></span>
6042b15cb3dSCy Schubert
605052d159aSCy Schubert<p>This is the &ldquo;do not listen to virtual interfaces&rdquo; option.
6062b15cb3dSCy SchubertDo not listen to virtual interfaces, defined as those with
6072b15cb3dSCy Schubertnames containing a colon.  This option is deprecated.  Please
6082b15cb3dSCy Schubertconsider using the configuration file <code>interface</code> command, which
6092b15cb3dSCy Schubertis more versatile.
610052d159aSCy Schubert</p><hr>
611a466cc55SCy Schubert<span id="ntpd-modifymmtimer"></span><div class="header">
612052d159aSCy Schubert<p>
613052d159aSCy SchubertNext: <a href="#ntpd-nice" accesskey="n" rel="next">ntpd nice</a>, Previous: <a href="#ntpd-novirtualips" accesskey="p" rel="prev">ntpd novirtualips</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
6142b15cb3dSCy Schubert</div>
615a466cc55SCy Schubert<span id="modifymmtimer-option-_0028_002dM_0029"></span><h4 class="subsection">1.1.15 modifymmtimer option (-M)</h4>
616a466cc55SCy Schubert<span id="index-ntpd_002dmodifymmtimer"></span>
6172b15cb3dSCy Schubert
618052d159aSCy Schubert<p>This is the &ldquo;modify multimedia timer (windows only)&rdquo; option.
619052d159aSCy Schubert</p>
620052d159aSCy Schubert<p>This option has some usage constraints.  It:
621052d159aSCy Schubert</p><ul>
6222b15cb3dSCy Schubert<li> must be compiled in by defining <code>SYS_WINNT</code> during the compilation.
623052d159aSCy Schubert</li></ul>
6242b15cb3dSCy Schubert
6252b15cb3dSCy Schubert<p>Set the Windows Multimedia Timer to highest resolution.  This
6262b15cb3dSCy Schubertensures the resolution does not change while ntpd is running,
6272b15cb3dSCy Schubertavoiding timekeeping glitches associated with changes.
628052d159aSCy Schubert</p><hr>
629a466cc55SCy Schubert<span id="ntpd-nice"></span><div class="header">
630052d159aSCy Schubert<p>
631052d159aSCy SchubertNext: <a href="#ntpd-pidfile" accesskey="n" rel="next">ntpd pidfile</a>, Previous: <a href="#ntpd-modifymmtimer" accesskey="p" rel="prev">ntpd modifymmtimer</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
6322b15cb3dSCy Schubert</div>
633a466cc55SCy Schubert<span id="nice-option-_0028_002dN_0029"></span><h4 class="subsection">1.1.16 nice option (-N)</h4>
634a466cc55SCy Schubert<span id="index-ntpd_002dnice"></span>
6352b15cb3dSCy Schubert
636052d159aSCy Schubert<p>This is the &ldquo;run at high priority&rdquo; option.
6372b15cb3dSCy SchubertTo the extent permitted by the operating system, run
6382b15cb3dSCy Schubert<code>ntpd</code>
6392b15cb3dSCy Schubertat the highest priority.
640052d159aSCy Schubert</p><hr>
641a466cc55SCy Schubert<span id="ntpd-pidfile"></span><div class="header">
642052d159aSCy Schubert<p>
643052d159aSCy SchubertNext: <a href="#ntpd-priority" accesskey="n" rel="next">ntpd priority</a>, Previous: <a href="#ntpd-nice" accesskey="p" rel="prev">ntpd nice</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
6442b15cb3dSCy Schubert</div>
645a466cc55SCy Schubert<span id="pidfile-option-_0028_002dp_0029"></span><h4 class="subsection">1.1.17 pidfile option (-p)</h4>
646a466cc55SCy Schubert<span id="index-ntpd_002dpidfile"></span>
6472b15cb3dSCy Schubert
648052d159aSCy Schubert<p>This is the &ldquo;path to the pid file&rdquo; option.
6492b15cb3dSCy SchubertThis option takes a string argument.
6502b15cb3dSCy SchubertSpecify the name and path of the file used to record
651052d159aSCy Schubert<code>ntpd</code>&rsquo;s
6522b15cb3dSCy Schubertprocess ID.
6532b15cb3dSCy SchubertThis is the same operation as the
6542b15cb3dSCy Schubert<code>pidfile</code> <kbd>pidfile</kbd>
6552b15cb3dSCy Schubertconfiguration file directive.
656052d159aSCy Schubert</p><hr>
657a466cc55SCy Schubert<span id="ntpd-priority"></span><div class="header">
658052d159aSCy Schubert<p>
659052d159aSCy SchubertNext: <a href="#ntpd-quit" accesskey="n" rel="next">ntpd quit</a>, Previous: <a href="#ntpd-pidfile" accesskey="p" rel="prev">ntpd pidfile</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
6602b15cb3dSCy Schubert</div>
661a466cc55SCy Schubert<span id="priority-option-_0028_002dP_0029"></span><h4 class="subsection">1.1.18 priority option (-P)</h4>
662a466cc55SCy Schubert<span id="index-ntpd_002dpriority"></span>
6632b15cb3dSCy Schubert
664052d159aSCy Schubert<p>This is the &ldquo;process priority&rdquo; option.
6652b15cb3dSCy SchubertThis option takes a number argument.
6662b15cb3dSCy SchubertTo the extent permitted by the operating system, run
6672b15cb3dSCy Schubert<code>ntpd</code>
6682b15cb3dSCy Schubertat the specified
6692b15cb3dSCy Schubert<code>sched_setscheduler(SCHED_FIFO)</code>
6702b15cb3dSCy Schubertpriority.
671052d159aSCy Schubert</p><hr>
672a466cc55SCy Schubert<span id="ntpd-quit"></span><div class="header">
673052d159aSCy Schubert<p>
674052d159aSCy SchubertNext: <a href="#ntpd-propagationdelay" accesskey="n" rel="next">ntpd propagationdelay</a>, Previous: <a href="#ntpd-priority" accesskey="p" rel="prev">ntpd priority</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
6752b15cb3dSCy Schubert</div>
676a466cc55SCy Schubert<span id="quit-option-_0028_002dq_0029"></span><h4 class="subsection">1.1.19 quit option (-q)</h4>
677a466cc55SCy Schubert<span id="index-ntpd_002dquit"></span>
6782b15cb3dSCy Schubert
679052d159aSCy Schubert<p>This is the &ldquo;set the time and quit&rdquo; option.
680052d159aSCy Schubert</p>
681052d159aSCy Schubert<p>This option has some usage constraints.  It:
682052d159aSCy Schubert</p><ul>
6832b15cb3dSCy Schubert<li> must not appear in combination with any of the following options:
6842b15cb3dSCy Schubertsaveconfigquit, wait-sync.
685052d159aSCy Schubert</li></ul>
6862b15cb3dSCy Schubert
6872b15cb3dSCy Schubert<p><code>ntpd</code>
6882b15cb3dSCy Schubertwill not daemonize and will exit after the clock is first
6892b15cb3dSCy Schubertsynchronized.  This behavior mimics that of the
6902b15cb3dSCy Schubert<code>ntpdate</code>
6912b15cb3dSCy Schubertprogram, which will soon be replaced with a shell script.
6922b15cb3dSCy SchubertThe
6932b15cb3dSCy Schubert<code>-g</code>
6942b15cb3dSCy Schubertand
6952b15cb3dSCy Schubert<code>-x</code>
6962b15cb3dSCy Schubertoptions can be used with this option.
6972b15cb3dSCy SchubertNote: The kernel time discipline is disabled with this option.
698052d159aSCy Schubert</p><hr>
699a466cc55SCy Schubert<span id="ntpd-propagationdelay"></span><div class="header">
700052d159aSCy Schubert<p>
701052d159aSCy SchubertNext: <a href="#ntpd-saveconfigquit" accesskey="n" rel="next">ntpd saveconfigquit</a>, Previous: <a href="#ntpd-quit" accesskey="p" rel="prev">ntpd quit</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
7022b15cb3dSCy Schubert</div>
703a466cc55SCy Schubert<span id="propagationdelay-option-_0028_002dr_0029"></span><h4 class="subsection">1.1.20 propagationdelay option (-r)</h4>
704a466cc55SCy Schubert<span id="index-ntpd_002dpropagationdelay"></span>
7052b15cb3dSCy Schubert
706052d159aSCy Schubert<p>This is the &ldquo;broadcast/propagation delay&rdquo; option.
7072b15cb3dSCy SchubertThis option takes a string argument.
7082b15cb3dSCy SchubertSpecify the default propagation delay from the broadcast/multicast server to this client. This is necessary only if the delay cannot be computed automatically by the protocol.
709052d159aSCy Schubert</p><hr>
710a466cc55SCy Schubert<span id="ntpd-saveconfigquit"></span><div class="header">
711052d159aSCy Schubert<p>
712052d159aSCy SchubertNext: <a href="#ntpd-statsdir" accesskey="n" rel="next">ntpd statsdir</a>, Previous: <a href="#ntpd-propagationdelay" accesskey="p" rel="prev">ntpd propagationdelay</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
7132b15cb3dSCy Schubert</div>
714a466cc55SCy Schubert<span id="saveconfigquit-option"></span><h4 class="subsection">1.1.21 saveconfigquit option</h4>
715a466cc55SCy Schubert<span id="index-ntpd_002dsaveconfigquit"></span>
7162b15cb3dSCy Schubert
717052d159aSCy Schubert<p>This is the &ldquo;save parsed configuration and quit&rdquo; option.
7182b15cb3dSCy SchubertThis option takes a string argument.
719052d159aSCy Schubert</p>
720052d159aSCy Schubert<p>This option has some usage constraints.  It:
721052d159aSCy Schubert</p><ul>
7222b15cb3dSCy Schubert<li> must be compiled in by defining <code>SAVECONFIG</code> during the compilation.
723052d159aSCy Schubert</li><li> must not appear in combination with any of the following options:
7242b15cb3dSCy Schubertquit, wait-sync.
725052d159aSCy Schubert</li></ul>
7262b15cb3dSCy Schubert
7272b15cb3dSCy Schubert<p>Cause <code>ntpd</code> to parse its startup configuration file and save an
7282b15cb3dSCy Schubertequivalent to the given filename and exit.  This option was
7292b15cb3dSCy Schubertdesigned for automated testing.
730052d159aSCy Schubert</p><hr>
731a466cc55SCy Schubert<span id="ntpd-statsdir"></span><div class="header">
732052d159aSCy Schubert<p>
733052d159aSCy SchubertNext: <a href="#ntpd-trustedkey" accesskey="n" rel="next">ntpd trustedkey</a>, Previous: <a href="#ntpd-saveconfigquit" accesskey="p" rel="prev">ntpd saveconfigquit</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
7342b15cb3dSCy Schubert</div>
735a466cc55SCy Schubert<span id="statsdir-option-_0028_002ds_0029"></span><h4 class="subsection">1.1.22 statsdir option (-s)</h4>
736a466cc55SCy Schubert<span id="index-ntpd_002dstatsdir"></span>
7372b15cb3dSCy Schubert
738052d159aSCy Schubert<p>This is the &ldquo;statistics file location&rdquo; option.
7392b15cb3dSCy SchubertThis option takes a string argument.
7402b15cb3dSCy SchubertSpecify the directory path for files created by the statistics facility.
7412b15cb3dSCy SchubertThis is the same operation as the
7422b15cb3dSCy Schubert<code>statsdir</code> <kbd>statsdir</kbd>
7432b15cb3dSCy Schubertconfiguration file directive.
744052d159aSCy Schubert</p><hr>
745a466cc55SCy Schubert<span id="ntpd-trustedkey"></span><div class="header">
746052d159aSCy Schubert<p>
747052d159aSCy SchubertNext: <a href="#ntpd-user" accesskey="n" rel="next">ntpd user</a>, Previous: <a href="#ntpd-statsdir" accesskey="p" rel="prev">ntpd statsdir</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
7482b15cb3dSCy Schubert</div>
749a466cc55SCy Schubert<span id="trustedkey-option-_0028_002dt_0029"></span><h4 class="subsection">1.1.23 trustedkey option (-t)</h4>
750a466cc55SCy Schubert<span id="index-ntpd_002dtrustedkey"></span>
7512b15cb3dSCy Schubert
752052d159aSCy Schubert<p>This is the &ldquo;trusted key number&rdquo; option.
753052d159aSCy SchubertThis option takes a string argument <samp>tkey</samp>.
754052d159aSCy Schubert</p>
755052d159aSCy Schubert<p>This option has some usage constraints.  It:
756052d159aSCy Schubert</p><ul>
7572b15cb3dSCy Schubert<li> may appear an unlimited number of times.
758052d159aSCy Schubert</li></ul>
7592b15cb3dSCy Schubert
7602b15cb3dSCy Schubert<p>Add the specified key number to the trusted key list.
761052d159aSCy Schubert</p><hr>
762a466cc55SCy Schubert<span id="ntpd-user"></span><div class="header">
763052d159aSCy Schubert<p>
764052d159aSCy SchubertNext: <a href="#ntpd-updateinterval" accesskey="n" rel="next">ntpd updateinterval</a>, Previous: <a href="#ntpd-trustedkey" accesskey="p" rel="prev">ntpd trustedkey</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
7652b15cb3dSCy Schubert</div>
766a466cc55SCy Schubert<span id="user-option-_0028_002du_0029"></span><h4 class="subsection">1.1.24 user option (-u)</h4>
767a466cc55SCy Schubert<span id="index-ntpd_002duser"></span>
7682b15cb3dSCy Schubert
769052d159aSCy Schubert<p>This is the &ldquo;run as userid (or userid:groupid)&rdquo; option.
7702b15cb3dSCy SchubertThis option takes a string argument.
771052d159aSCy Schubert</p>
772052d159aSCy Schubert<p>This option has some usage constraints.  It:
773052d159aSCy Schubert</p><ul>
7742b15cb3dSCy Schubert<li> must be compiled in by defining <code>HAVE_DROPROOT</code> during the compilation.
775052d159aSCy Schubert</li></ul>
7762b15cb3dSCy Schubert
7772b15cb3dSCy Schubert<p>Specify a user, and optionally a group, to switch to.
7782b15cb3dSCy SchubertThis option is only available if the OS supports adjusting the clock
7792b15cb3dSCy Schubertwithout full root privileges.
7802b15cb3dSCy SchubertThis option is supported under NetBSD (configure with
7812b15cb3dSCy Schubert<code>--enable-clockctl</code>) or Linux (configure with
7822b15cb3dSCy Schubert<code>--enable-linuxcaps</code>) or Solaris (configure with <code>--enable-solarisprivs</code>).
783052d159aSCy Schubert</p><hr>
784a466cc55SCy Schubert<span id="ntpd-updateinterval"></span><div class="header">
785052d159aSCy Schubert<p>
786052d159aSCy SchubertNext: <a href="#ntpd-wait_002dsync" accesskey="n" rel="next">ntpd wait-sync</a>, Previous: <a href="#ntpd-user" accesskey="p" rel="prev">ntpd user</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
7872b15cb3dSCy Schubert</div>
788a466cc55SCy Schubert<span id="updateinterval-option-_0028_002dU_0029"></span><h4 class="subsection">1.1.25 updateinterval option (-U)</h4>
789a466cc55SCy Schubert<span id="index-ntpd_002dupdateinterval"></span>
7902b15cb3dSCy Schubert
791052d159aSCy Schubert<p>This is the &ldquo;interval in seconds between scans for new or dropped interfaces&rdquo; option.
7922b15cb3dSCy SchubertThis option takes a number argument.
7932b15cb3dSCy SchubertGive the time in seconds between two scans for new or dropped interfaces.
7942b15cb3dSCy SchubertFor systems with routing socket support the scans will be performed shortly after the interface change
7952b15cb3dSCy Schuberthas been detected by the system.
7962b15cb3dSCy SchubertUse 0 to disable scanning. 60 seconds is the minimum time between scans.
797052d159aSCy Schubert</p><hr>
798a466cc55SCy Schubert<span id="ntpd-wait_002dsync"></span><div class="header">
799052d159aSCy Schubert<p>
800052d159aSCy SchubertNext: <a href="#ntpd-slew" accesskey="n" rel="next">ntpd slew</a>, Previous: <a href="#ntpd-updateinterval" accesskey="p" rel="prev">ntpd updateinterval</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
8012b15cb3dSCy Schubert</div>
802a466cc55SCy Schubert<span id="wait_002dsync-option-_0028_002dw_0029"></span><h4 class="subsection">1.1.26 wait-sync option (-w)</h4>
803a466cc55SCy Schubert<span id="index-ntpd_002dwait_002dsync"></span>
8042b15cb3dSCy Schubert
805052d159aSCy Schubert<p>This is the &ldquo;seconds to wait for first clock sync&rdquo; option.
8062b15cb3dSCy SchubertThis option takes a number argument.
807052d159aSCy Schubert</p>
808052d159aSCy Schubert<p>This option has some usage constraints.  It:
809052d159aSCy Schubert</p><ul>
8102b15cb3dSCy Schubert<li> must be compiled in by defining <code>HAVE_WORKING_FORK</code> during the compilation.
811052d159aSCy Schubert</li><li> must not appear in combination with any of the following options:
8122b15cb3dSCy Schubertnofork, quit, saveconfigquit.
813052d159aSCy Schubert</li></ul>
8142b15cb3dSCy Schubert
815052d159aSCy Schubert<p>If greater than zero, alters <code>ntpd</code>&rsquo;s behavior when forking to
8162b15cb3dSCy Schubertdaemonize.  Instead of exiting with status 0 immediately after
8172b15cb3dSCy Schubertthe fork, the parent waits up to the specified number of
8182b15cb3dSCy Schubertseconds for the child to first synchronize the clock.  The exit
8192b15cb3dSCy Schubertstatus is zero (success) if the clock was synchronized,
8202b15cb3dSCy Schubertotherwise it is <code>ETIMEDOUT</code>.
8212b15cb3dSCy SchubertThis provides the option for a script starting <code>ntpd</code> to easily
8222b15cb3dSCy Schubertwait for the first set of the clock before proceeding.
823052d159aSCy Schubert</p><hr>
824a466cc55SCy Schubert<span id="ntpd-slew"></span><div class="header">
825052d159aSCy Schubert<p>
826052d159aSCy SchubertNext: <a href="#ntpd-usepcc" accesskey="n" rel="next">ntpd usepcc</a>, Previous: <a href="#ntpd-wait_002dsync" accesskey="p" rel="prev">ntpd wait-sync</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
8272b15cb3dSCy Schubert</div>
828a466cc55SCy Schubert<span id="slew-option-_0028_002dx_0029"></span><h4 class="subsection">1.1.27 slew option (-x)</h4>
829a466cc55SCy Schubert<span id="index-ntpd_002dslew"></span>
8302b15cb3dSCy Schubert
831052d159aSCy Schubert<p>This is the &ldquo;slew up to 600 seconds&rdquo; option.
8322b15cb3dSCy SchubertNormally, the time is slewed if the offset is less than the step threshold, which is 128 ms by default, and stepped if above the threshold.
8332b15cb3dSCy SchubertThis option sets the threshold to 600 s, which is well within the accuracy window to set the clock manually.
8342b15cb3dSCy SchubertNote: Since the slew rate of typical Unix kernels is limited to 0.5 ms/s, each second of adjustment requires an amortization interval of 2000 s.
8352b15cb3dSCy SchubertThus, an adjustment as much as 600 s will take almost 14 days to complete.
8362b15cb3dSCy SchubertThis option can be used with the
8372b15cb3dSCy Schubert<code>-g</code>
8382b15cb3dSCy Schubertand
8392b15cb3dSCy Schubert<code>-q</code>
8402b15cb3dSCy Schubertoptions.
8412b15cb3dSCy SchubertSee the
8422b15cb3dSCy Schubert<code>tinker</code>
8432b15cb3dSCy Schubertconfiguration file directive for other options.
8442b15cb3dSCy SchubertNote: The kernel time discipline is disabled with this option.
845052d159aSCy Schubert</p><hr>
846a466cc55SCy Schubert<span id="ntpd-usepcc"></span><div class="header">
847052d159aSCy Schubert<p>
848052d159aSCy SchubertNext: <a href="#ntpd-pccfreq" accesskey="n" rel="next">ntpd pccfreq</a>, Previous: <a href="#ntpd-slew" accesskey="p" rel="prev">ntpd slew</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
8492b15cb3dSCy Schubert</div>
850a466cc55SCy Schubert<span id="usepcc-option"></span><h4 class="subsection">1.1.28 usepcc option</h4>
851a466cc55SCy Schubert<span id="index-ntpd_002dusepcc"></span>
8522b15cb3dSCy Schubert
853052d159aSCy Schubert<p>This is the &ldquo;use cpu cycle counter (windows only)&rdquo; option.
854052d159aSCy Schubert</p>
855052d159aSCy Schubert<p>This option has some usage constraints.  It:
856052d159aSCy Schubert</p><ul>
8572b15cb3dSCy Schubert<li> must be compiled in by defining <code>SYS_WINNT</code> during the compilation.
858052d159aSCy Schubert</li></ul>
8592b15cb3dSCy Schubert
8602b15cb3dSCy Schubert<p>Attempt to substitute the CPU counter for <code>QueryPerformanceCounter</code>.
8612b15cb3dSCy SchubertThe CPU counter and <code>QueryPerformanceCounter</code> are compared, and if
8622b15cb3dSCy Schubertthey have the same frequency, the CPU counter (RDTSC on x86) is
8632b15cb3dSCy Schubertused directly, saving the overhead of a system call.
864052d159aSCy Schubert</p><hr>
865a466cc55SCy Schubert<span id="ntpd-pccfreq"></span><div class="header">
866052d159aSCy Schubert<p>
867052d159aSCy SchubertNext: <a href="#ntpd-mdns" accesskey="n" rel="next">ntpd mdns</a>, Previous: <a href="#ntpd-usepcc" accesskey="p" rel="prev">ntpd usepcc</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
8682b15cb3dSCy Schubert</div>
869a466cc55SCy Schubert<span id="pccfreq-option"></span><h4 class="subsection">1.1.29 pccfreq option</h4>
870a466cc55SCy Schubert<span id="index-ntpd_002dpccfreq"></span>
8712b15cb3dSCy Schubert
872052d159aSCy Schubert<p>This is the &ldquo;force cpu cycle counter use (windows only)&rdquo; option.
8732b15cb3dSCy SchubertThis option takes a string argument.
874052d159aSCy Schubert</p>
875052d159aSCy Schubert<p>This option has some usage constraints.  It:
876052d159aSCy Schubert</p><ul>
8772b15cb3dSCy Schubert<li> must be compiled in by defining <code>SYS_WINNT</code> during the compilation.
878052d159aSCy Schubert</li></ul>
8792b15cb3dSCy Schubert
8802b15cb3dSCy Schubert<p>Force substitution the CPU counter for <code>QueryPerformanceCounter</code>.
8812b15cb3dSCy SchubertThe CPU counter (RDTSC on x86) is used unconditionally with the
8822b15cb3dSCy Schubertgiven frequency (in Hz).
883052d159aSCy Schubert</p><hr>
884a466cc55SCy Schubert<span id="ntpd-mdns"></span><div class="header">
885052d159aSCy Schubert<p>
886052d159aSCy SchubertNext: <a href="#ntpd-config" accesskey="n" rel="next">ntpd config</a>, Previous: <a href="#ntpd-pccfreq" accesskey="p" rel="prev">ntpd pccfreq</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
8872b15cb3dSCy Schubert</div>
888a466cc55SCy Schubert<span id="mdns-option-_0028_002dm_0029"></span><h4 class="subsection">1.1.30 mdns option (-m)</h4>
889a466cc55SCy Schubert<span id="index-ntpd_002dmdns"></span>
8902b15cb3dSCy Schubert
891052d159aSCy Schubert<p>This is the &ldquo;register with mdns as a ntp server&rdquo; option.
892052d159aSCy Schubert</p>
893052d159aSCy Schubert<p>This option has some usage constraints.  It:
894052d159aSCy Schubert</p><ul>
8952b15cb3dSCy Schubert<li> must be compiled in by defining <code>HAVE_DNSREGISTRATION</code> during the compilation.
896052d159aSCy Schubert</li></ul>
8972b15cb3dSCy Schubert
8982b15cb3dSCy Schubert<p>Registers as an NTP server with the local mDNS server which allows
8992b15cb3dSCy Schubertthe server to be discovered via mDNS client lookup.
900052d159aSCy Schubert</p>
9012b15cb3dSCy Schubert
902052d159aSCy Schubert<hr>
903a466cc55SCy Schubert<span id="ntpd-config"></span><div class="header">
904052d159aSCy Schubert<p>
905052d159aSCy SchubertNext: <a href="#ntpd-exit-status" accesskey="n" rel="next">ntpd exit status</a>, Previous: <a href="#ntpd-mdns" accesskey="p" rel="prev">ntpd mdns</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
9062b15cb3dSCy Schubert</div>
907a466cc55SCy Schubert<span id="presetting_002fconfiguring-ntpd"></span><h4 class="subsection">1.1.31 presetting/configuring ntpd</h4>
9082b15cb3dSCy Schubert
9092b15cb3dSCy Schubert<p>Any option that is not marked as <i>not presettable</i> may be preset by
9102b15cb3dSCy Schubertloading values from environment variables named <code>NTPD</code> and <code>NTPD_&lt;OPTION_NAME&gt;</code>.  <code>&lt;OPTION_NAME&gt;</code> must be one of
9112b15cb3dSCy Schubertthe options listed above in upper case and segmented with underscores.
9122b15cb3dSCy SchubertThe <code>NTPD</code> variable will be tokenized and parsed like
9132b15cb3dSCy Schubertthe command line.  The remaining variables are tested for existence and their
9142b15cb3dSCy Schubertvalues are treated like option arguments.
915052d159aSCy Schubert</p>
9162b15cb3dSCy Schubert
9172b15cb3dSCy Schubert<p>The command line options relating to configuration and/or usage help are:
918052d159aSCy Schubert</p>
919a466cc55SCy Schubert<span id="version-_0028_002d_0029"></span><h4 class="subsubheading">version (-)</h4>
9202b15cb3dSCy Schubert
9212b15cb3dSCy Schubert<p>Print the program version to standard out, optionally with licensing
9222b15cb3dSCy Schubertinformation, then exit 0.  The optional argument specifies how much licensing
923a466cc55SCy Schubertdetail to provide.  The default is to print just the version.  The licensing information may be selected with an option argument.
9242b15cb3dSCy SchubertOnly the first letter of the argument is examined:
925052d159aSCy Schubert</p>
926052d159aSCy Schubert<dl compact="compact">
927052d159aSCy Schubert<dt>&lsquo;<samp>version</samp>&rsquo;</dt>
928052d159aSCy Schubert<dd><p>Only print the version.  This is the default.
929052d159aSCy Schubert</p></dd>
930052d159aSCy Schubert<dt>&lsquo;<samp>copyright</samp>&rsquo;</dt>
931052d159aSCy Schubert<dd><p>Name the copyright usage licensing terms.
932052d159aSCy Schubert</p></dd>
933052d159aSCy Schubert<dt>&lsquo;<samp>verbose</samp>&rsquo;</dt>
934052d159aSCy Schubert<dd><p>Print the full copyright usage licensing terms.
935052d159aSCy Schubert</p></dd>
9362b15cb3dSCy Schubert</dl>
9372b15cb3dSCy Schubert
938052d159aSCy Schubert<hr>
939a466cc55SCy Schubert<span id="ntpd-exit-status"></span><div class="header">
940052d159aSCy Schubert<p>
941052d159aSCy SchubertNext: <a href="#ntpd-Usage" accesskey="n" rel="next">ntpd Usage</a>, Previous: <a href="#ntpd-config" accesskey="p" rel="prev">ntpd config</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
9422b15cb3dSCy Schubert</div>
943a466cc55SCy Schubert<span id="ntpd-exit-status-1"></span><h4 class="subsection">1.1.32 ntpd exit status</h4>
9442b15cb3dSCy Schubert
9452b15cb3dSCy Schubert<p>One of the following exit values will be returned:
946052d159aSCy Schubert</p><dl compact="compact">
947052d159aSCy Schubert<dt>&lsquo;<samp>0 (EXIT_SUCCESS)</samp>&rsquo;</dt>
948052d159aSCy Schubert<dd><p>Successful program execution.
949052d159aSCy Schubert</p></dd>
950052d159aSCy Schubert<dt>&lsquo;<samp>1 (EXIT_FAILURE)</samp>&rsquo;</dt>
951052d159aSCy Schubert<dd><p>The operation failed or the command syntax was not valid.
952052d159aSCy Schubert</p></dd>
9532b15cb3dSCy Schubert</dl>
954052d159aSCy Schubert<hr>
955a466cc55SCy Schubert<span id="ntpd-Usage"></span><div class="header">
956052d159aSCy Schubert<p>
957052d159aSCy SchubertNext: <a href="#ntpd-Files" accesskey="n" rel="next">ntpd Files</a>, Previous: <a href="#ntpd-exit-status" accesskey="p" rel="prev">ntpd exit status</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
9582b15cb3dSCy Schubert</div>
959a466cc55SCy Schubert<span id="ntpd-Usage-1"></span><h4 class="subsection">1.1.33 ntpd Usage</h4>
960052d159aSCy Schubert<hr>
961a466cc55SCy Schubert<span id="ntpd-Files"></span><div class="header">
962052d159aSCy Schubert<p>
963052d159aSCy SchubertNext: <a href="#ntpd-See-Also" accesskey="n" rel="next">ntpd See Also</a>, Previous: <a href="#ntpd-Usage" accesskey="p" rel="prev">ntpd Usage</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
9642b15cb3dSCy Schubert</div>
965a466cc55SCy Schubert<span id="ntpd-Files-1"></span><h4 class="subsection">1.1.34 ntpd Files</h4>
966052d159aSCy Schubert<hr>
967a466cc55SCy Schubert<span id="ntpd-See-Also"></span><div class="header">
968052d159aSCy Schubert<p>
969052d159aSCy SchubertNext: <a href="#ntpd-Bugs" accesskey="n" rel="next">ntpd Bugs</a>, Previous: <a href="#ntpd-Files" accesskey="p" rel="prev">ntpd Files</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
9702b15cb3dSCy Schubert</div>
971a466cc55SCy Schubert<span id="ntpd-See-Also-1"></span><h4 class="subsection">1.1.35 ntpd See Also</h4>
972052d159aSCy Schubert<hr>
973a466cc55SCy Schubert<span id="ntpd-Bugs"></span><div class="header">
974052d159aSCy Schubert<p>
975052d159aSCy SchubertNext: <a href="#ntpd-Notes" accesskey="n" rel="next">ntpd Notes</a>, Previous: <a href="#ntpd-See-Also" accesskey="p" rel="prev">ntpd See Also</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
9762b15cb3dSCy Schubert</div>
977a466cc55SCy Schubert<span id="ntpd-Bugs-1"></span><h4 class="subsection">1.1.36 ntpd Bugs</h4>
978052d159aSCy Schubert<hr>
979a466cc55SCy Schubert<span id="ntpd-Notes"></span><div class="header">
980052d159aSCy Schubert<p>
981052d159aSCy SchubertPrevious: <a href="#ntpd-Bugs" accesskey="p" rel="prev">ntpd Bugs</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> &nbsp; </p>
9822b15cb3dSCy Schubert</div>
983a466cc55SCy Schubert<span id="ntpd-Notes-1"></span><h4 class="subsection">1.1.37 ntpd Notes</h4>
9842b15cb3dSCy Schubert
985052d159aSCy Schubert<hr>
986a466cc55SCy Schubert<span id="Usage"></span><div class="header">
987052d159aSCy Schubert<p>
988052d159aSCy SchubertPrevious: <a href="#ntpd-Invocation" accesskey="p" rel="prev">ntpd Invocation</a>, Up: <a href="#ntpd-Description" accesskey="u" rel="up">ntpd Description</a> &nbsp; </p>
9892b15cb3dSCy Schubert</div>
990a466cc55SCy Schubert<span id="Usage-1"></span><h3 class="section">1.2 Usage</h3>
9912b15cb3dSCy Schubert
992052d159aSCy Schubert<table>
993052d159aSCy Schubert<thead><tr><th width="23%">What</th><th width="23%">Default</th><th width="5%">Flag</th><th width="15%">Option</th></tr></thead>
994052d159aSCy Schubert<tr><td width="23%">configuration file</td><td width="23%"><code>/etc/ntp.conf</code></td><td width="5%"><code>-c</code></td><td width="15%"><code>conffile</code></td></tr>
995052d159aSCy Schubert<tr><td width="23%">frequency file</td><td width="23%">none</td><td width="5%"><code>-f</code></td><td width="15%"><code>driftfile</code></td></tr>
996052d159aSCy Schubert<tr><td width="23%">leapseconds file</td><td width="23%">none</td><td width="5%"></td><td width="15%"><code>leapfile</code></td></tr>
997052d159aSCy Schubert<tr><td width="23%">process ID file</td><td width="23%">none</td><td width="5%"><code>-p</code></td><td width="15%"><code>pidfile</code></td></tr>
998052d159aSCy Schubert<tr><td width="23%">log file</td><td width="23%">system log</td><td width="5%"><code>-l</code></td><td width="15%"><code>logfile</code></td></tr>
999052d159aSCy Schubert<tr><td width="23%">include file</td><td width="23%">none</td><td width="5%">none</td><td width="15%"><code>includefile</code></td></tr>
1000052d159aSCy Schubert<tr><td width="23%">statistics path</td><td width="23%"><code>/var/NTP</code></td><td width="5%"><code>-s</code></td><td width="15%"><code>statsdir</code></td></tr>
1001052d159aSCy Schubert<tr><td width="23%">keys path</td><td width="23%"><code>/usr/local/etc</code></td><td width="5%"><code>-k</code></td><td width="15%"><code>keysdir</code></td></tr>
1002052d159aSCy Schubert</table>
1003052d159aSCy Schubert<hr>
10042b15cb3dSCy Schubert
1005052d159aSCy Schubert
1006052d159aSCy Schubert
1007052d159aSCy Schubert</body>
1008052d159aSCy Schubert</html>
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