1275970Scy<html lang="en"> 2275970Scy<head> 3275970Scy<title>ntpd: Network Time Protocol (NTP) Daemon User's Manual</title> 4275970Scy<meta http-equiv="Content-Type" content="text/html"> 5275970Scy<meta name="description" content="ntpd: Network Time Protocol (NTP) Daemon User's Manual"> 6275970Scy<meta name="generator" content="makeinfo 4.7"> 7275970Scy<link title="Top" rel="top" href="#Top"> 8275970Scy<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> 9275970Scy<meta http-equiv="Content-Style-Type" content="text/css"> 10275970Scy<style type="text/css"><!-- 11275970Scy pre.display { font-family:inherit } 12275970Scy pre.format { font-family:inherit } 13275970Scy pre.smalldisplay { font-family:inherit; font-size:smaller } 14275970Scy pre.smallformat { font-family:inherit; font-size:smaller } 15275970Scy pre.smallexample { font-size:smaller } 16275970Scy pre.smalllisp { font-size:smaller } 17275970Scy span.sc { font-variant:small-caps } 18275970Scy span.roman { font-family: serif; font-weight: normal; } 19275970Scy--></style> 20275970Scy</head> 21275970Scy<body> 22275970Scy<h1 class="settitle">ntpd: Network Time Protocol (NTP) Daemon User's Manual</h1> 23275970Scy<div class="node"> 24275970Scy<p><hr> 25275970Scy<a name="Top"></a>Next: <a rel="next" accesskey="n" href="#ntpd-Description">ntpd Description</a>, 26275970ScyPrevious: <a rel="previous" accesskey="p" href="#dir">(dir)</a>, 27275970ScyUp: <a rel="up" accesskey="u" href="#dir">(dir)</a> 28275970Scy<br> 29275970Scy</div> 30275970Scy 31275970Scy<h2 class="unnumbered">ntpd: Network Time Protocol (NTP) Daemon User Manual</h2> 32275970Scy 33275970Scy<p>The <code>ntpd</code> program is an operating system daemon that synchronizes the 34275970Scysystem clock to remote NTP time servers or local reference clocks. 35275970ScyIt is a complete implementation of NTP version 4 defined by RFC-5905, but 36275970Scyalso retains compatible with version 3 defined by RFC-1305 and versions 37275970Scy1 and 2, defined by RFC-1059 and RFC-1119, respectively. 38275970ScyThe program can operate in any of several modes, including client/server, 39275970Scysymmetric and broadcast modes, and with both symmetric-key and public-key 40275970Scycryptography. 41275970Scy 42310419Sdelphij <p>This document applies to version 4.2.8p9 of <code>ntpd</code>. 43275970Scy 44275970Scy<ul class="menu"> 45275970Scy<li><a accesskey="1" href="#ntpd-Description">ntpd Description</a>: Description 46275970Scy<li><a accesskey="2" href="#ntpd-Invocation">ntpd Invocation</a>: Invoking ntpd 47275970Scy<li><a accesskey="3" href="#Usage">Usage</a>: Usage 48275970Scy</ul> 49275970Scy 50275970Scy<div class="node"> 51275970Scy<p><hr> 52275970Scy<a name="ntpd-Description"></a> 53275970Scy<br> 54275970Scy</div> 55275970Scy 56275970Scy<!-- node-name, next, previous, up --> 57275970Scy<h3 class="section">Description</h3> 58275970Scy 59275970Scy<p>The <code>ntpd</code> program ordinarily requires 60275970Scya configuration file described at <a href="#ntp_002econf">ntp.conf</a>. 61275970ScyThis configuration file contains configuration commands described on 62275970Scythe pages listed above. 63275970ScyHowever a client can discover remote servers and configure them 64275970Scyautomatically. 65275970ScyThis makes it possible to deploy a fleet of workstations without 66275970Scyspecifying configuration details specific to the local environment. 67275970Scy 68275970Scy <p>The <code>ntpd</code> program normally operates continuously while adjusting the 69275970Scysystem time and frequency, but in some cases this might not be 70275970Scypractical. 71275970ScyWith the <code>-q</code> option <code>ntpd</code> operates as in continuous mode, but 72275970Scyexits just after setting the clock for the first time. 73275970ScyMost applications will probably want to specify the <code>iburst</code> 74275970Scyoption with the <code>server</code> command. 75275970ScyWith this option an initial volley of messages is exchanged to 76275970Scygroom the data and set the clock in about ten seconds' time. 77275970ScyIf nothing is heard after a few minutes' time, 78275970Scythe daemon times out and exits without setting the clock. 79275970Scy 80275970Scy<div class="node"> 81275970Scy<p><hr> 82275970Scy<a name="ntpd-Invocation"></a> 83275970Scy<br> 84275970Scy</div> 85275970Scy 86275970Scy<h3 class="section">Invoking ntpd</h3> 87275970Scy 88275970Scy<p><a name="index-ntpd-1"></a><a name="index-NTP-daemon-program-2"></a> 89275970Scy 90275970Scy <p>The 91275970Scy<code>ntpd</code> 92275970Scyutility is an operating system daemon which sets 93275970Scyand maintains the system time of day in synchronism with Internet 94275970Scystandard time servers. 95275970ScyIt is a complete implementation of the 96275970ScyNetwork Time Protocol (NTP) version 4, as defined by RFC-5905, 97275970Scybut also retains compatibility with 98275970Scyversion 3, as defined by RFC-1305, and versions 1 99275970Scyand 2, as defined by RFC-1059 and RFC-1119, respectively. 100275970Scy 101275970Scy <p>The 102275970Scy<code>ntpd</code> 103275970Scyutility does most computations in 64-bit floating point 104275970Scyarithmetic and does relatively clumsy 64-bit fixed point operations 105275970Scyonly when necessary to preserve the ultimate precision, about 232 106275970Scypicoseconds. 107275970ScyWhile the ultimate precision is not achievable with 108275970Scyordinary workstations and networks of today, it may be required 109275970Scywith future gigahertz CPU clocks and gigabit LANs. 110275970Scy 111275970Scy <p>Ordinarily, 112275970Scy<code>ntpd</code> 113275970Scyreads the 114275970Scy<code>ntp.conf(5)</code> 115275970Scyconfiguration file at startup time in order to determine the 116275970Scysynchronization sources and operating modes. 117275970ScyIt is also possible to 118275970Scyspecify a working, although limited, configuration entirely on the 119275970Scycommand line, obviating the need for a configuration file. 120275970ScyThis may 121275970Scybe particularly useful when the local host is to be configured as a 122275970Scybroadcast/multicast client, with all peers being determined by 123275970Scylistening to broadcasts at run time. 124275970Scy 125275970Scy <p>If NetInfo support is built into 126275970Scy<code>ntpd</code> 127275970Scythen 128275970Scy<code>ntpd</code> 129275970Scywill attempt to read its configuration from the 130275970ScyNetInfo if the default 131275970Scy<code>ntp.conf(5)</code> 132275970Scyfile cannot be read and no file is 133275970Scyspecified by the 134275970Scy<code>-c</code> 135275970Scyoption. 136275970Scy 137275970Scy <p>Various internal 138275970Scy<code>ntpd</code> 139275970Scyvariables can be displayed and 140275970Scyconfiguration options altered while the 141275970Scy<code>ntpd</code> 142275970Scyis running 143275970Scyusing the 144275970Scy<code>ntpq(1ntpqmdoc)</code> 145275970Scyand 146275970Scy<code>ntpdc(1ntpdcmdoc)</code> 147275970Scyutility programs. 148275970Scy 149275970Scy <p>When 150275970Scy<code>ntpd</code> 151275970Scystarts it looks at the value of 152275970Scy<code>umask(2)</code>, 153275970Scyand if zero 154275970Scy<code>ntpd</code> 155275970Scywill set the 156275970Scy<code>umask(2)</code> 157275970Scyto 022. 158275970Scy 159275970Scy <p>This section was generated by <strong>AutoGen</strong>, 160275970Scyusing the <code>agtexi-cmd</code> template and the option descriptions for the <code>ntpd</code> program. 161275970ScyThis software is released under the NTP license, <http://ntp.org/license>;. 162275970Scy 163275970Scy<ul class="menu"> 164275970Scy<li><a accesskey="1" href="#ntpd-usage">ntpd usage</a>: ntpd help/usage (<span class="option">--help</span>) 165275970Scy<li><a accesskey="2" href="#ntpd-ipv4">ntpd ipv4</a>: ipv4 option (-4) 166275970Scy<li><a accesskey="3" href="#ntpd-ipv6">ntpd ipv6</a>: ipv6 option (-6) 167275970Scy<li><a accesskey="4" href="#ntpd-authreq">ntpd authreq</a>: authreq option (-a) 168275970Scy<li><a accesskey="5" href="#ntpd-authnoreq">ntpd authnoreq</a>: authnoreq option (-A) 169275970Scy<li><a accesskey="6" href="#ntpd-configfile">ntpd configfile</a>: configfile option (-c) 170275970Scy<li><a accesskey="7" href="#ntpd-driftfile">ntpd driftfile</a>: driftfile option (-f) 171275970Scy<li><a accesskey="8" href="#ntpd-panicgate">ntpd panicgate</a>: panicgate option (-g) 172290000Sglebius<li><a accesskey="9" href="#ntpd-force_002dstep_002donce">ntpd force-step-once</a>: force-step-once option (-G) 173290000Sglebius<li><a href="#ntpd-jaildir">ntpd jaildir</a>: jaildir option (-i) 174275970Scy<li><a href="#ntpd-interface">ntpd interface</a>: interface option (-I) 175275970Scy<li><a href="#ntpd-keyfile">ntpd keyfile</a>: keyfile option (-k) 176275970Scy<li><a href="#ntpd-logfile">ntpd logfile</a>: logfile option (-l) 177275970Scy<li><a href="#ntpd-novirtualips">ntpd novirtualips</a>: novirtualips option (-L) 178275970Scy<li><a href="#ntpd-modifymmtimer">ntpd modifymmtimer</a>: modifymmtimer option (-M) 179275970Scy<li><a href="#ntpd-nice">ntpd nice</a>: nice option (-N) 180275970Scy<li><a href="#ntpd-pidfile">ntpd pidfile</a>: pidfile option (-p) 181275970Scy<li><a href="#ntpd-priority">ntpd priority</a>: priority option (-P) 182275970Scy<li><a href="#ntpd-quit">ntpd quit</a>: quit option (-q) 183275970Scy<li><a href="#ntpd-propagationdelay">ntpd propagationdelay</a>: propagationdelay option (-r) 184275970Scy<li><a href="#ntpd-saveconfigquit">ntpd saveconfigquit</a>: saveconfigquit option 185275970Scy<li><a href="#ntpd-statsdir">ntpd statsdir</a>: statsdir option (-s) 186275970Scy<li><a href="#ntpd-trustedkey">ntpd trustedkey</a>: trustedkey option (-t) 187275970Scy<li><a href="#ntpd-user">ntpd user</a>: user option (-u) 188275970Scy<li><a href="#ntpd-updateinterval">ntpd updateinterval</a>: updateinterval option (-U) 189275970Scy<li><a href="#ntpd-wait_002dsync">ntpd wait-sync</a>: wait-sync option (-w) 190275970Scy<li><a href="#ntpd-slew">ntpd slew</a>: slew option (-x) 191275970Scy<li><a href="#ntpd-usepcc">ntpd usepcc</a>: usepcc option 192275970Scy<li><a href="#ntpd-pccfreq">ntpd pccfreq</a>: pccfreq option 193275970Scy<li><a href="#ntpd-mdns">ntpd mdns</a>: mdns option (-m) 194275970Scy<li><a href="#ntpd-config">ntpd config</a>: presetting/configuring ntpd 195275970Scy<li><a href="#ntpd-exit-status">ntpd exit status</a>: exit status 196275970Scy<li><a href="#ntpd-Usage">ntpd Usage</a>: Usage 197275970Scy<li><a href="#ntpd-Files">ntpd Files</a>: Files 198275970Scy<li><a href="#ntpd-See-Also">ntpd See Also</a>: See Also 199275970Scy<li><a href="#ntpd-Bugs">ntpd Bugs</a>: Bugs 200275970Scy<li><a href="#ntpd-Notes">ntpd Notes</a>: Notes 201275970Scy</ul> 202275970Scy 203275970Scy<div class="node"> 204275970Scy<p><hr> 205275970Scy<a name="ntpd-usage"></a>Next: <a rel="next" accesskey="n" href="#ntpd-ipv4">ntpd ipv4</a>, 206275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 207275970Scy<br> 208275970Scy</div> 209275970Scy 210275970Scy<h4 class="subsection">ntpd help/usage (<span class="option">--help</span>)</h4> 211275970Scy 212275970Scy<p><a name="index-ntpd-help-3"></a> 213275970ScyThis is the automatically generated usage text for ntpd. 214275970Scy 215275970Scy <p>The text printed is the same whether selected with the <code>help</code> option 216275970Scy(<span class="option">--help</span>) or the <code>more-help</code> option (<span class="option">--more-help</span>). <code>more-help</code> will print 217275970Scythe usage text by passing it through a pager program. 218275970Scy<code>more-help</code> is disabled on platforms without a working 219275970Scy<code>fork(2)</code> function. The <code>PAGER</code> environment variable is 220275970Scyused to select the program, defaulting to <span class="file">more</span>. Both will exit 221275970Scywith a status code of 0. 222275970Scy 223310419Sdelphij<pre class="example">ntpd - NTP daemon program - Ver. 4.2.8p9-RC 224275970ScyUsage: ntpd [ -<flag> [<val>] | --<name>[{=| }<val>] ]... \ 225275970Scy [ <server1> ... <serverN> ] 226275970Scy Flg Arg Option-Name Description 227275970Scy -4 no ipv4 Force IPv4 DNS name resolution 228275970Scy - prohibits the option 'ipv6' 229275970Scy -6 no ipv6 Force IPv6 DNS name resolution 230275970Scy - prohibits the option 'ipv4' 231275970Scy -a no authreq Require crypto authentication 232275970Scy - prohibits the option 'authnoreq' 233275970Scy -A no authnoreq Do not require crypto authentication 234275970Scy - prohibits the option 'authreq' 235275970Scy -b no bcastsync Allow us to sync to broadcast servers 236275970Scy -c Str configfile configuration file name 237275970Scy -d no debug-level Increase debug verbosity level 238275970Scy - may appear multiple times 239275970Scy -D Num set-debug-level Set the debug verbosity level 240275970Scy - may appear multiple times 241275970Scy -f Str driftfile frequency drift file name 242275970Scy -g no panicgate Allow the first adjustment to be Big 243275970Scy - may appear multiple times 244290000Sglebius -G no force-step-once Step any initial offset correction. 245275970Scy -i Str jaildir Jail directory 246275970Scy -I Str interface Listen on an interface name or address 247275970Scy - may appear multiple times 248275970Scy -k Str keyfile path to symmetric keys 249275970Scy -l Str logfile path to the log file 250275970Scy -L no novirtualips Do not listen to virtual interfaces 251275970Scy -n no nofork Do not fork 252275970Scy - prohibits the option 'wait-sync' 253275970Scy -N no nice Run at high priority 254275970Scy -p Str pidfile path to the PID file 255275970Scy -P Num priority Process priority 256275970Scy -q no quit Set the time and quit 257275970Scy - prohibits these options: 258275970Scy saveconfigquit 259275970Scy wait-sync 260275970Scy -r Str propagationdelay Broadcast/propagation delay 261275970Scy Str saveconfigquit Save parsed configuration and quit 262275970Scy - prohibits these options: 263275970Scy quit 264275970Scy wait-sync 265275970Scy -s Str statsdir Statistics file location 266275970Scy -t Str trustedkey Trusted key number 267275970Scy - may appear multiple times 268275970Scy -u Str user Run as userid (or userid:groupid) 269275970Scy -U Num updateinterval interval in seconds between scans for new or dropped interfaces 270275970Scy Str var make ARG an ntp variable (RW) 271275970Scy - may appear multiple times 272275970Scy Str dvar make ARG an ntp variable (RW|DEF) 273275970Scy - may appear multiple times 274275970Scy -w Num wait-sync Seconds to wait for first clock sync 275275970Scy - prohibits these options: 276275970Scy nofork 277275970Scy quit 278275970Scy saveconfigquit 279275970Scy -x no slew Slew up to 600 seconds 280275970Scy opt version output version information and exit 281275970Scy -? no help display extended usage information and exit 282275970Scy -! no more-help extended usage information passed thru pager 283275970Scy 284275970ScyOptions are specified by doubled hyphens and their name or by a single 285275970Scyhyphen and the flag character. 286275970Scy 287275970Scy 288275970ScyThe following option preset mechanisms are supported: 289275970Scy - examining environment variables named NTPD_* 290275970Scy 291275970ScyPlease send bug reports to: <http://bugs.ntp.org, bugs@ntp.org> 292275970Scy</pre> 293275970Scy <div class="node"> 294275970Scy<p><hr> 295275970Scy<a name="ntpd-ipv4"></a>Next: <a rel="next" accesskey="n" href="#ntpd-ipv6">ntpd ipv6</a>, 296275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-usage">ntpd usage</a>, 297275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 298275970Scy<br> 299275970Scy</div> 300275970Scy 301275970Scy<h4 class="subsection">ipv4 option (-4)</h4> 302275970Scy 303275970Scy<p><a name="index-ntpd_002dipv4-4"></a> 304275970ScyThis is the “force ipv4 dns name resolution” option. 305275970Scy 306275970Scy<p class="noindent">This option has some usage constraints. It: 307275970Scy <ul> 308275970Scy<li>must not appear in combination with any of the following options: 309275970Scyipv6. 310275970Scy</ul> 311275970Scy 312275970Scy <p>Force DNS resolution of following host names on the command line 313275970Scyto the IPv4 namespace. 314275970Scy<div class="node"> 315275970Scy<p><hr> 316275970Scy<a name="ntpd-ipv6"></a>Next: <a rel="next" accesskey="n" href="#ntpd-authreq">ntpd authreq</a>, 317275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-ipv4">ntpd ipv4</a>, 318275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 319275970Scy<br> 320275970Scy</div> 321275970Scy 322275970Scy<h4 class="subsection">ipv6 option (-6)</h4> 323275970Scy 324275970Scy<p><a name="index-ntpd_002dipv6-5"></a> 325275970ScyThis is the “force ipv6 dns name resolution” option. 326275970Scy 327275970Scy<p class="noindent">This option has some usage constraints. It: 328275970Scy <ul> 329275970Scy<li>must not appear in combination with any of the following options: 330275970Scyipv4. 331275970Scy</ul> 332275970Scy 333275970Scy <p>Force DNS resolution of following host names on the command line 334275970Scyto the IPv6 namespace. 335275970Scy<div class="node"> 336275970Scy<p><hr> 337275970Scy<a name="ntpd-authreq"></a>Next: <a rel="next" accesskey="n" href="#ntpd-authnoreq">ntpd authnoreq</a>, 338275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-ipv6">ntpd ipv6</a>, 339275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 340275970Scy<br> 341275970Scy</div> 342275970Scy 343275970Scy<h4 class="subsection">authreq option (-a)</h4> 344275970Scy 345275970Scy<p><a name="index-ntpd_002dauthreq-6"></a> 346275970ScyThis is the “require crypto authentication” option. 347275970Scy 348275970Scy<p class="noindent">This option has some usage constraints. It: 349275970Scy <ul> 350275970Scy<li>must not appear in combination with any of the following options: 351275970Scyauthnoreq. 352275970Scy</ul> 353275970Scy 354275970Scy <p>Require cryptographic authentication for broadcast client, 355275970Scymulticast client and symmetric passive associations. 356275970ScyThis is the default. 357275970Scy<div class="node"> 358275970Scy<p><hr> 359275970Scy<a name="ntpd-authnoreq"></a>Next: <a rel="next" accesskey="n" href="#ntpd-configfile">ntpd configfile</a>, 360275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-authreq">ntpd authreq</a>, 361275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 362275970Scy<br> 363275970Scy</div> 364275970Scy 365275970Scy<h4 class="subsection">authnoreq option (-A)</h4> 366275970Scy 367275970Scy<p><a name="index-ntpd_002dauthnoreq-7"></a> 368275970ScyThis is the “do not require crypto authentication” option. 369275970Scy 370275970Scy<p class="noindent">This option has some usage constraints. It: 371275970Scy <ul> 372275970Scy<li>must not appear in combination with any of the following options: 373275970Scyauthreq. 374275970Scy</ul> 375275970Scy 376275970Scy <p>Do not require cryptographic authentication for broadcast client, 377275970Scymulticast client and symmetric passive associations. 378275970ScyThis is almost never a good idea. 379275970Scy<div class="node"> 380275970Scy<p><hr> 381275970Scy<a name="ntpd-configfile"></a>Next: <a rel="next" accesskey="n" href="#ntpd-driftfile">ntpd driftfile</a>, 382275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-authnoreq">ntpd authnoreq</a>, 383275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 384275970Scy<br> 385275970Scy</div> 386275970Scy 387275970Scy<h4 class="subsection">configfile option (-c)</h4> 388275970Scy 389275970Scy<p><a name="index-ntpd_002dconfigfile-8"></a> 390275970ScyThis is the “configuration file name” option. 391275970ScyThis option takes a string argument. 392275970ScyThe name and path of the configuration file, 393275970Scy<span class="file">/etc/ntp.conf</span> 394275970Scyby default. 395275970Scy<div class="node"> 396275970Scy<p><hr> 397275970Scy<a name="ntpd-driftfile"></a>Next: <a rel="next" accesskey="n" href="#ntpd-panicgate">ntpd panicgate</a>, 398275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-configfile">ntpd configfile</a>, 399275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 400275970Scy<br> 401275970Scy</div> 402275970Scy 403275970Scy<h4 class="subsection">driftfile option (-f)</h4> 404275970Scy 405275970Scy<p><a name="index-ntpd_002ddriftfile-9"></a> 406275970ScyThis is the “frequency drift file name” option. 407275970ScyThis option takes a string argument. 408275970ScyThe name and path of the frequency file, 409275970Scy<span class="file">/etc/ntp.drift</span> 410275970Scyby default. 411275970ScyThis is the same operation as the 412275970Scy<code>driftfile</code> <kbd>driftfile</kbd> 413275970Scyconfiguration specification in the 414275970Scy<span class="file">/etc/ntp.conf</span> 415275970Scyfile. 416275970Scy<div class="node"> 417275970Scy<p><hr> 418290000Sglebius<a name="ntpd-panicgate"></a>Next: <a rel="next" accesskey="n" href="#ntpd-force_002dstep_002donce">ntpd force-step-once</a>, 419275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-driftfile">ntpd driftfile</a>, 420275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 421275970Scy<br> 422275970Scy</div> 423275970Scy 424275970Scy<h4 class="subsection">panicgate option (-g)</h4> 425275970Scy 426275970Scy<p><a name="index-ntpd_002dpanicgate-10"></a> 427275970ScyThis is the “allow the first adjustment to be big” option. 428275970Scy 429275970Scy<p class="noindent">This option has some usage constraints. It: 430275970Scy <ul> 431275970Scy<li>may appear an unlimited number of times. 432275970Scy</ul> 433275970Scy 434275970Scy <p>Normally, 435275970Scy<code>ntpd</code> 436275970Scyexits 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, 437275970Scy<code>ntpd</code> 438275970Scywill exit with a message to the system log. This option can be used with the 439275970Scy<code>-q</code> 440275970Scyand 441275970Scy<code>-x</code> 442275970Scyoptions. 443275970ScySee the 444275970Scy<code>tinker</code> 445275970Scyconfiguration file directive for other options. 446275970Scy<div class="node"> 447275970Scy<p><hr> 448290000Sglebius<a name="ntpd-force_002dstep_002donce"></a>Next: <a rel="next" accesskey="n" href="#ntpd-jaildir">ntpd jaildir</a>, 449275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-panicgate">ntpd panicgate</a>, 450275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 451275970Scy<br> 452275970Scy</div> 453275970Scy 454290000Sglebius<h4 class="subsection">force-step-once option (-G)</h4> 455290000Sglebius 456290000Sglebius<p><a name="index-ntpd_002dforce_002dstep_002donce-11"></a> 457290000SglebiusThis is the “step any initial offset correction.” option. 458290000SglebiusNormally, 459290000Sglebius<code>ntpd</code> 460290000Sglebiussteps the time if the time offset exceeds the step threshold, 461290000Sglebiuswhich is 128 ms by default, and otherwise slews the time. 462290000SglebiusThis option forces the initial offset correction to be stepped, 463290000Sglebiusso the highest time accuracy can be achieved quickly. 464290000SglebiusHowever, this may also cause the time to be stepped back 465290000Sglebiusso this option must not be used if 466290000Sglebiusapplications requiring monotonic time are running. 467290000SglebiusSee the <code>tinker</code> configuration file directive for other options. 468290000Sglebius<div class="node"> 469290000Sglebius<p><hr> 470290000Sglebius<a name="ntpd-jaildir"></a>Next: <a rel="next" accesskey="n" href="#ntpd-interface">ntpd interface</a>, 471290000SglebiusPrevious: <a rel="previous" accesskey="p" href="#ntpd-force_002dstep_002donce">ntpd force-step-once</a>, 472290000SglebiusUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 473290000Sglebius<br> 474290000Sglebius</div> 475290000Sglebius 476275970Scy<h4 class="subsection">jaildir option (-i)</h4> 477275970Scy 478290000Sglebius<p><a name="index-ntpd_002djaildir-12"></a> 479275970ScyThis is the “jail directory” option. 480275970ScyThis option takes a string argument. 481275970Scy 482275970Scy<p class="noindent">This option has some usage constraints. It: 483275970Scy <ul> 484275970Scy<li>must be compiled in by defining <code>HAVE_DROPROOT</code> during the compilation. 485275970Scy</ul> 486275970Scy 487275970Scy <p>Chroot the server to the directory 488275970Scy<kbd>jaildir</kbd> 489275970Scy. 490275970ScyThis option also implies that the server attempts to drop root privileges at startup. 491275970ScyYou may need to also specify a 492275970Scy<code>-u</code> 493275970Scyoption. 494275970ScyThis option is only available if the OS supports adjusting the clock 495275970Scywithout full root privileges. 496275970ScyThis option is supported under NetBSD (configure with 497275970Scy<code>--enable-clockctl</code>) or Linux (configure with 498275970Scy<code>--enable-linuxcaps</code>) or Solaris (configure with <code>--enable-solarisprivs</code>). 499275970Scy<div class="node"> 500275970Scy<p><hr> 501275970Scy<a name="ntpd-interface"></a>Next: <a rel="next" accesskey="n" href="#ntpd-keyfile">ntpd keyfile</a>, 502275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-jaildir">ntpd jaildir</a>, 503275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 504275970Scy<br> 505275970Scy</div> 506275970Scy 507275970Scy<h4 class="subsection">interface option (-I)</h4> 508275970Scy 509290000Sglebius<p><a name="index-ntpd_002dinterface-13"></a> 510275970ScyThis is the “listen on an interface name or address” option. 511275970ScyThis option takes a string argument <span class="file">iface</span>. 512275970Scy 513275970Scy<p class="noindent">This option has some usage constraints. It: 514275970Scy <ul> 515275970Scy<li>may appear an unlimited number of times. 516275970Scy</ul> 517275970Scy 518275970Scy <p>Open the network address given, or all the addresses associated with the 519275970Scygiven interface name. This option may appear multiple times. This option 520275970Scyalso implies not opening other addresses, except wildcard and localhost. 521275970ScyThis option is deprecated. Please consider using the configuration file 522275970Scy<code>interface</code> command, which is more versatile. 523275970Scy<div class="node"> 524275970Scy<p><hr> 525275970Scy<a name="ntpd-keyfile"></a>Next: <a rel="next" accesskey="n" href="#ntpd-logfile">ntpd logfile</a>, 526275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-interface">ntpd interface</a>, 527275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 528275970Scy<br> 529275970Scy</div> 530275970Scy 531275970Scy<h4 class="subsection">keyfile option (-k)</h4> 532275970Scy 533290000Sglebius<p><a name="index-ntpd_002dkeyfile-14"></a> 534275970ScyThis is the “path to symmetric keys” option. 535275970ScyThis option takes a string argument. 536275970ScySpecify the name and path of the symmetric key file. 537275970Scy<span class="file">/etc/ntp.keys</span> 538275970Scyis the default. 539275970ScyThis is the same operation as the 540275970Scy<code>keys</code> <kbd>keyfile</kbd> 541275970Scyconfiguration file directive. 542275970Scy<div class="node"> 543275970Scy<p><hr> 544275970Scy<a name="ntpd-logfile"></a>Next: <a rel="next" accesskey="n" href="#ntpd-novirtualips">ntpd novirtualips</a>, 545275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-keyfile">ntpd keyfile</a>, 546275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 547275970Scy<br> 548275970Scy</div> 549275970Scy 550275970Scy<h4 class="subsection">logfile option (-l)</h4> 551275970Scy 552290000Sglebius<p><a name="index-ntpd_002dlogfile-15"></a> 553275970ScyThis is the “path to the log file” option. 554275970ScyThis option takes a string argument. 555275970ScySpecify the name and path of the log file. 556275970ScyThe default is the system log file. 557275970ScyThis is the same operation as the 558275970Scy<code>logfile</code> <kbd>logfile</kbd> 559275970Scyconfiguration file directive. 560275970Scy<div class="node"> 561275970Scy<p><hr> 562275970Scy<a name="ntpd-novirtualips"></a>Next: <a rel="next" accesskey="n" href="#ntpd-modifymmtimer">ntpd modifymmtimer</a>, 563275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-logfile">ntpd logfile</a>, 564275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 565275970Scy<br> 566275970Scy</div> 567275970Scy 568275970Scy<h4 class="subsection">novirtualips option (-L)</h4> 569275970Scy 570290000Sglebius<p><a name="index-ntpd_002dnovirtualips-16"></a> 571275970ScyThis is the “do not listen to virtual interfaces” option. 572275970ScyDo not listen to virtual interfaces, defined as those with 573275970Scynames containing a colon. This option is deprecated. Please 574275970Scyconsider using the configuration file <code>interface</code> command, which 575275970Scyis more versatile. 576275970Scy<div class="node"> 577275970Scy<p><hr> 578275970Scy<a name="ntpd-modifymmtimer"></a>Next: <a rel="next" accesskey="n" href="#ntpd-nice">ntpd nice</a>, 579275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-novirtualips">ntpd novirtualips</a>, 580275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 581275970Scy<br> 582275970Scy</div> 583275970Scy 584275970Scy<h4 class="subsection">modifymmtimer option (-M)</h4> 585275970Scy 586290000Sglebius<p><a name="index-ntpd_002dmodifymmtimer-17"></a> 587275970ScyThis is the “modify multimedia timer (windows only)” option. 588275970Scy 589275970Scy<p class="noindent">This option has some usage constraints. It: 590275970Scy <ul> 591275970Scy<li>must be compiled in by defining <code>SYS_WINNT</code> during the compilation. 592275970Scy</ul> 593275970Scy 594275970Scy <p>Set the Windows Multimedia Timer to highest resolution. This 595275970Scyensures the resolution does not change while ntpd is running, 596275970Scyavoiding timekeeping glitches associated with changes. 597275970Scy<div class="node"> 598275970Scy<p><hr> 599275970Scy<a name="ntpd-nice"></a>Next: <a rel="next" accesskey="n" href="#ntpd-pidfile">ntpd pidfile</a>, 600275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-modifymmtimer">ntpd modifymmtimer</a>, 601275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 602275970Scy<br> 603275970Scy</div> 604275970Scy 605275970Scy<h4 class="subsection">nice option (-N)</h4> 606275970Scy 607290000Sglebius<p><a name="index-ntpd_002dnice-18"></a> 608275970ScyThis is the “run at high priority” option. 609275970ScyTo the extent permitted by the operating system, run 610275970Scy<code>ntpd</code> 611275970Scyat the highest priority. 612275970Scy<div class="node"> 613275970Scy<p><hr> 614275970Scy<a name="ntpd-pidfile"></a>Next: <a rel="next" accesskey="n" href="#ntpd-priority">ntpd priority</a>, 615275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-nice">ntpd nice</a>, 616275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 617275970Scy<br> 618275970Scy</div> 619275970Scy 620275970Scy<h4 class="subsection">pidfile option (-p)</h4> 621275970Scy 622290000Sglebius<p><a name="index-ntpd_002dpidfile-19"></a> 623275970ScyThis is the “path to the pid file” option. 624275970ScyThis option takes a string argument. 625275970ScySpecify the name and path of the file used to record 626275970Scy<code>ntpd</code>'s 627275970Scyprocess ID. 628275970ScyThis is the same operation as the 629275970Scy<code>pidfile</code> <kbd>pidfile</kbd> 630275970Scyconfiguration file directive. 631275970Scy<div class="node"> 632275970Scy<p><hr> 633275970Scy<a name="ntpd-priority"></a>Next: <a rel="next" accesskey="n" href="#ntpd-quit">ntpd quit</a>, 634275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-pidfile">ntpd pidfile</a>, 635275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 636275970Scy<br> 637275970Scy</div> 638275970Scy 639275970Scy<h4 class="subsection">priority option (-P)</h4> 640275970Scy 641290000Sglebius<p><a name="index-ntpd_002dpriority-20"></a> 642275970ScyThis is the “process priority” option. 643275970ScyThis option takes a number argument. 644275970ScyTo the extent permitted by the operating system, run 645275970Scy<code>ntpd</code> 646275970Scyat the specified 647275970Scy<code>sched_setscheduler(SCHED_FIFO)</code> 648275970Scypriority. 649275970Scy<div class="node"> 650275970Scy<p><hr> 651275970Scy<a name="ntpd-quit"></a>Next: <a rel="next" accesskey="n" href="#ntpd-propagationdelay">ntpd propagationdelay</a>, 652275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-priority">ntpd priority</a>, 653275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 654275970Scy<br> 655275970Scy</div> 656275970Scy 657275970Scy<h4 class="subsection">quit option (-q)</h4> 658275970Scy 659290000Sglebius<p><a name="index-ntpd_002dquit-21"></a> 660275970ScyThis is the “set the time and quit” option. 661275970Scy 662275970Scy<p class="noindent">This option has some usage constraints. It: 663275970Scy <ul> 664275970Scy<li>must not appear in combination with any of the following options: 665275970Scysaveconfigquit, wait-sync. 666275970Scy</ul> 667275970Scy 668275970Scy <p><code>ntpd</code> 669275970Scywill not daemonize and will exit after the clock is first 670275970Scysynchronized. This behavior mimics that of the 671275970Scy<code>ntpdate</code> 672275970Scyprogram, which will soon be replaced with a shell script. 673275970ScyThe 674275970Scy<code>-g</code> 675275970Scyand 676275970Scy<code>-x</code> 677275970Scyoptions can be used with this option. 678275970ScyNote: The kernel time discipline is disabled with this option. 679275970Scy<div class="node"> 680275970Scy<p><hr> 681275970Scy<a name="ntpd-propagationdelay"></a>Next: <a rel="next" accesskey="n" href="#ntpd-saveconfigquit">ntpd saveconfigquit</a>, 682275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-quit">ntpd quit</a>, 683275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 684275970Scy<br> 685275970Scy</div> 686275970Scy 687275970Scy<h4 class="subsection">propagationdelay option (-r)</h4> 688275970Scy 689290000Sglebius<p><a name="index-ntpd_002dpropagationdelay-22"></a> 690275970ScyThis is the “broadcast/propagation delay” option. 691275970ScyThis option takes a string argument. 692275970ScySpecify 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. 693275970Scy<div class="node"> 694275970Scy<p><hr> 695275970Scy<a name="ntpd-saveconfigquit"></a>Next: <a rel="next" accesskey="n" href="#ntpd-statsdir">ntpd statsdir</a>, 696275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-propagationdelay">ntpd propagationdelay</a>, 697275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 698275970Scy<br> 699275970Scy</div> 700275970Scy 701275970Scy<h4 class="subsection">saveconfigquit option</h4> 702275970Scy 703290000Sglebius<p><a name="index-ntpd_002dsaveconfigquit-23"></a> 704275970ScyThis is the “save parsed configuration and quit” option. 705275970ScyThis option takes a string argument. 706275970Scy 707275970Scy<p class="noindent">This option has some usage constraints. It: 708275970Scy <ul> 709275970Scy<li>must be compiled in by defining <code>SAVECONFIG</code> during the compilation. 710275970Scy<li>must not appear in combination with any of the following options: 711275970Scyquit, wait-sync. 712275970Scy</ul> 713275970Scy 714275970Scy <p>Cause <code>ntpd</code> to parse its startup configuration file and save an 715275970Scyequivalent to the given filename and exit. This option was 716275970Scydesigned for automated testing. 717275970Scy<div class="node"> 718275970Scy<p><hr> 719275970Scy<a name="ntpd-statsdir"></a>Next: <a rel="next" accesskey="n" href="#ntpd-trustedkey">ntpd trustedkey</a>, 720275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-saveconfigquit">ntpd saveconfigquit</a>, 721275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 722275970Scy<br> 723275970Scy</div> 724275970Scy 725275970Scy<h4 class="subsection">statsdir option (-s)</h4> 726275970Scy 727290000Sglebius<p><a name="index-ntpd_002dstatsdir-24"></a> 728275970ScyThis is the “statistics file location” option. 729275970ScyThis option takes a string argument. 730275970ScySpecify the directory path for files created by the statistics facility. 731275970ScyThis is the same operation as the 732275970Scy<code>statsdir</code> <kbd>statsdir</kbd> 733275970Scyconfiguration file directive. 734275970Scy<div class="node"> 735275970Scy<p><hr> 736275970Scy<a name="ntpd-trustedkey"></a>Next: <a rel="next" accesskey="n" href="#ntpd-user">ntpd user</a>, 737275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-statsdir">ntpd statsdir</a>, 738275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 739275970Scy<br> 740275970Scy</div> 741275970Scy 742275970Scy<h4 class="subsection">trustedkey option (-t)</h4> 743275970Scy 744290000Sglebius<p><a name="index-ntpd_002dtrustedkey-25"></a> 745275970ScyThis is the “trusted key number” option. 746275970ScyThis option takes a string argument <span class="file">tkey</span>. 747275970Scy 748275970Scy<p class="noindent">This option has some usage constraints. It: 749275970Scy <ul> 750275970Scy<li>may appear an unlimited number of times. 751275970Scy</ul> 752275970Scy 753275970Scy <p>Add the specified key number to the trusted key list. 754275970Scy<div class="node"> 755275970Scy<p><hr> 756275970Scy<a name="ntpd-user"></a>Next: <a rel="next" accesskey="n" href="#ntpd-updateinterval">ntpd updateinterval</a>, 757275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-trustedkey">ntpd trustedkey</a>, 758275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 759275970Scy<br> 760275970Scy</div> 761275970Scy 762275970Scy<h4 class="subsection">user option (-u)</h4> 763275970Scy 764290000Sglebius<p><a name="index-ntpd_002duser-26"></a> 765275970ScyThis is the “run as userid (or userid:groupid)” option. 766275970ScyThis option takes a string argument. 767275970Scy 768275970Scy<p class="noindent">This option has some usage constraints. It: 769275970Scy <ul> 770275970Scy<li>must be compiled in by defining <code>HAVE_DROPROOT</code> during the compilation. 771275970Scy</ul> 772275970Scy 773275970Scy <p>Specify a user, and optionally a group, to switch to. 774275970ScyThis option is only available if the OS supports adjusting the clock 775275970Scywithout full root privileges. 776275970ScyThis option is supported under NetBSD (configure with 777275970Scy<code>--enable-clockctl</code>) or Linux (configure with 778275970Scy<code>--enable-linuxcaps</code>) or Solaris (configure with <code>--enable-solarisprivs</code>). 779275970Scy<div class="node"> 780275970Scy<p><hr> 781275970Scy<a name="ntpd-updateinterval"></a>Next: <a rel="next" accesskey="n" href="#ntpd-wait_002dsync">ntpd wait-sync</a>, 782275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-user">ntpd user</a>, 783275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 784275970Scy<br> 785275970Scy</div> 786275970Scy 787275970Scy<h4 class="subsection">updateinterval option (-U)</h4> 788275970Scy 789290000Sglebius<p><a name="index-ntpd_002dupdateinterval-27"></a> 790275970ScyThis is the “interval in seconds between scans for new or dropped interfaces” option. 791275970ScyThis option takes a number argument. 792275970ScyGive the time in seconds between two scans for new or dropped interfaces. 793275970ScyFor systems with routing socket support the scans will be performed shortly after the interface change 794275970Scyhas been detected by the system. 795275970ScyUse 0 to disable scanning. 60 seconds is the minimum time between scans. 796275970Scy<div class="node"> 797275970Scy<p><hr> 798275970Scy<a name="ntpd-wait_002dsync"></a>Next: <a rel="next" accesskey="n" href="#ntpd-slew">ntpd slew</a>, 799275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-updateinterval">ntpd updateinterval</a>, 800275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 801275970Scy<br> 802275970Scy</div> 803275970Scy 804275970Scy<h4 class="subsection">wait-sync option (-w)</h4> 805275970Scy 806290000Sglebius<p><a name="index-ntpd_002dwait_002dsync-28"></a> 807275970ScyThis is the “seconds to wait for first clock sync” option. 808275970ScyThis option takes a number argument. 809275970Scy 810275970Scy<p class="noindent">This option has some usage constraints. It: 811275970Scy <ul> 812275970Scy<li>must be compiled in by defining <code>HAVE_WORKING_FORK</code> during the compilation. 813275970Scy<li>must not appear in combination with any of the following options: 814275970Scynofork, quit, saveconfigquit. 815275970Scy</ul> 816275970Scy 817275970Scy <p>If greater than zero, alters <code>ntpd</code>'s behavior when forking to 818275970Scydaemonize. Instead of exiting with status 0 immediately after 819275970Scythe fork, the parent waits up to the specified number of 820275970Scyseconds for the child to first synchronize the clock. The exit 821275970Scystatus is zero (success) if the clock was synchronized, 822275970Scyotherwise it is <code>ETIMEDOUT</code>. 823275970ScyThis provides the option for a script starting <code>ntpd</code> to easily 824275970Scywait for the first set of the clock before proceeding. 825275970Scy<div class="node"> 826275970Scy<p><hr> 827275970Scy<a name="ntpd-slew"></a>Next: <a rel="next" accesskey="n" href="#ntpd-usepcc">ntpd usepcc</a>, 828275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-wait_002dsync">ntpd wait-sync</a>, 829275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 830275970Scy<br> 831275970Scy</div> 832275970Scy 833275970Scy<h4 class="subsection">slew option (-x)</h4> 834275970Scy 835290000Sglebius<p><a name="index-ntpd_002dslew-29"></a> 836275970ScyThis is the “slew up to 600 seconds” option. 837275970ScyNormally, 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. 838275970ScyThis option sets the threshold to 600 s, which is well within the accuracy window to set the clock manually. 839275970ScyNote: 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. 840275970ScyThus, an adjustment as much as 600 s will take almost 14 days to complete. 841275970ScyThis option can be used with the 842275970Scy<code>-g</code> 843275970Scyand 844275970Scy<code>-q</code> 845275970Scyoptions. 846275970ScySee the 847275970Scy<code>tinker</code> 848275970Scyconfiguration file directive for other options. 849275970ScyNote: The kernel time discipline is disabled with this option. 850275970Scy<div class="node"> 851275970Scy<p><hr> 852275970Scy<a name="ntpd-usepcc"></a>Next: <a rel="next" accesskey="n" href="#ntpd-pccfreq">ntpd pccfreq</a>, 853275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-slew">ntpd slew</a>, 854275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 855275970Scy<br> 856275970Scy</div> 857275970Scy 858275970Scy<h4 class="subsection">usepcc option</h4> 859275970Scy 860290000Sglebius<p><a name="index-ntpd_002dusepcc-30"></a> 861275970ScyThis is the “use cpu cycle counter (windows only)” option. 862275970Scy 863275970Scy<p class="noindent">This option has some usage constraints. It: 864275970Scy <ul> 865275970Scy<li>must be compiled in by defining <code>SYS_WINNT</code> during the compilation. 866275970Scy</ul> 867275970Scy 868275970Scy <p>Attempt to substitute the CPU counter for <code>QueryPerformanceCounter</code>. 869275970ScyThe CPU counter and <code>QueryPerformanceCounter</code> are compared, and if 870275970Scythey have the same frequency, the CPU counter (RDTSC on x86) is 871275970Scyused directly, saving the overhead of a system call. 872275970Scy<div class="node"> 873275970Scy<p><hr> 874275970Scy<a name="ntpd-pccfreq"></a>Next: <a rel="next" accesskey="n" href="#ntpd-mdns">ntpd mdns</a>, 875275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-usepcc">ntpd usepcc</a>, 876275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 877275970Scy<br> 878275970Scy</div> 879275970Scy 880275970Scy<h4 class="subsection">pccfreq option</h4> 881275970Scy 882290000Sglebius<p><a name="index-ntpd_002dpccfreq-31"></a> 883275970ScyThis is the “force cpu cycle counter use (windows only)” option. 884275970ScyThis option takes a string argument. 885275970Scy 886275970Scy<p class="noindent">This option has some usage constraints. It: 887275970Scy <ul> 888275970Scy<li>must be compiled in by defining <code>SYS_WINNT</code> during the compilation. 889275970Scy</ul> 890275970Scy 891275970Scy <p>Force substitution the CPU counter for <code>QueryPerformanceCounter</code>. 892275970ScyThe CPU counter (RDTSC on x86) is used unconditionally with the 893275970Scygiven frequency (in Hz). 894275970Scy<div class="node"> 895275970Scy<p><hr> 896275970Scy<a name="ntpd-mdns"></a>Next: <a rel="next" accesskey="n" href="#ntpd-config">ntpd config</a>, 897275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-pccfreq">ntpd pccfreq</a>, 898275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 899275970Scy<br> 900275970Scy</div> 901275970Scy 902275970Scy<h4 class="subsection">mdns option (-m)</h4> 903275970Scy 904290000Sglebius<p><a name="index-ntpd_002dmdns-32"></a> 905275970ScyThis is the “register with mdns as a ntp server” option. 906275970Scy 907275970Scy<p class="noindent">This option has some usage constraints. It: 908275970Scy <ul> 909275970Scy<li>must be compiled in by defining <code>HAVE_DNSREGISTRATION</code> during the compilation. 910275970Scy</ul> 911275970Scy 912275970Scy <p>Registers as an NTP server with the local mDNS server which allows 913275970Scythe server to be discovered via mDNS client lookup. 914275970Scy 915275970Scy<div class="node"> 916275970Scy<p><hr> 917275970Scy<a name="ntpd-config"></a>Next: <a rel="next" accesskey="n" href="#ntpd-exit-status">ntpd exit status</a>, 918275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-mdns">ntpd mdns</a>, 919275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 920275970Scy<br> 921275970Scy</div> 922275970Scy 923275970Scy<h4 class="subsection">presetting/configuring ntpd</h4> 924275970Scy 925275970Scy<p>Any option that is not marked as <i>not presettable</i> may be preset by 926275970Scyloading values from environment variables named <code>NTPD</code> and <code>NTPD_<OPTION_NAME></code>. <code><OPTION_NAME></code> must be one of 927275970Scythe options listed above in upper case and segmented with underscores. 928275970ScyThe <code>NTPD</code> variable will be tokenized and parsed like 929275970Scythe command line. The remaining variables are tested for existence and their 930275970Scyvalues are treated like option arguments. 931275970Scy 932275970Scy <p>The command line options relating to configuration and/or usage help are: 933275970Scy 934275970Scy<h5 class="subsubheading">version (-)</h5> 935275970Scy 936275970Scy<p>Print the program version to standard out, optionally with licensing 937275970Scyinformation, then exit 0. The optional argument specifies how much licensing 938275970Scydetail to provide. The default is to print just the version. The licensing infomation may be selected with an option argument. 939275970ScyOnly the first letter of the argument is examined: 940275970Scy 941275970Scy <dl> 942275970Scy<dt><span class="samp">version</span><dd>Only print the version. This is the default. 943275970Scy<br><dt><span class="samp">copyright</span><dd>Name the copyright usage licensing terms. 944275970Scy<br><dt><span class="samp">verbose</span><dd>Print the full copyright usage licensing terms. 945275970Scy</dl> 946275970Scy 947275970Scy<div class="node"> 948275970Scy<p><hr> 949275970Scy<a name="ntpd-exit-status"></a>Next: <a rel="next" accesskey="n" href="#ntpd-Usage">ntpd Usage</a>, 950275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-config">ntpd config</a>, 951275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 952275970Scy<br> 953275970Scy</div> 954275970Scy 955275970Scy<h4 class="subsection">ntpd exit status</h4> 956275970Scy 957275970Scy<p>One of the following exit values will be returned: 958275970Scy <dl> 959275970Scy<dt><span class="samp">0 (EXIT_SUCCESS)</span><dd>Successful program execution. 960275970Scy<br><dt><span class="samp">1 (EXIT_FAILURE)</span><dd>The operation failed or the command syntax was not valid. 961275970Scy</dl> 962275970Scy <div class="node"> 963275970Scy<p><hr> 964275970Scy<a name="ntpd-Usage"></a>Next: <a rel="next" accesskey="n" href="#ntpd-Files">ntpd Files</a>, 965275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-exit-status">ntpd exit status</a>, 966275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 967275970Scy<br> 968275970Scy</div> 969275970Scy 970275970Scy<h4 class="subsection">ntpd Usage</h4> 971275970Scy 972275970Scy<div class="node"> 973275970Scy<p><hr> 974275970Scy<a name="ntpd-Files"></a>Next: <a rel="next" accesskey="n" href="#ntpd-See-Also">ntpd See Also</a>, 975275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-Usage">ntpd Usage</a>, 976275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 977275970Scy<br> 978275970Scy</div> 979275970Scy 980275970Scy<h4 class="subsection">ntpd Files</h4> 981275970Scy 982275970Scy<div class="node"> 983275970Scy<p><hr> 984275970Scy<a name="ntpd-See-Also"></a>Next: <a rel="next" accesskey="n" href="#ntpd-Bugs">ntpd Bugs</a>, 985275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-Files">ntpd Files</a>, 986275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 987275970Scy<br> 988275970Scy</div> 989275970Scy 990275970Scy<h4 class="subsection">ntpd See Also</h4> 991275970Scy 992275970Scy<div class="node"> 993275970Scy<p><hr> 994275970Scy<a name="ntpd-Bugs"></a>Next: <a rel="next" accesskey="n" href="#ntpd-Notes">ntpd Notes</a>, 995275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-See-Also">ntpd See Also</a>, 996275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 997275970Scy<br> 998275970Scy</div> 999275970Scy 1000275970Scy<h4 class="subsection">ntpd Bugs</h4> 1001275970Scy 1002275970Scy<div class="node"> 1003275970Scy<p><hr> 1004275970Scy<a name="ntpd-Notes"></a>Previous: <a rel="previous" accesskey="p" href="#ntpd-Bugs">ntpd Bugs</a>, 1005275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 1006275970Scy<br> 1007275970Scy</div> 1008275970Scy 1009275970Scy<h4 class="subsection">ntpd Notes</h4> 1010275970Scy 1011275970Scy<div class="node"> 1012275970Scy<p><hr> 1013275970Scy<a name="Usage"></a> 1014275970Scy<br> 1015275970Scy</div> 1016275970Scy 1017275970Scy<!-- node-name, next, previous, up --> 1018275970Scy<h3 class="section">Usage</h3> 1019275970Scy 1020