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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 42275970Scy <p>This document applies to version 4.2.8 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) 172275970Scy<li><a accesskey="9" href="#ntpd-jaildir">ntpd jaildir</a>: jaildir option (-i) 173275970Scy<li><a href="#ntpd-interface">ntpd interface</a>: interface option (-I) 174275970Scy<li><a href="#ntpd-keyfile">ntpd keyfile</a>: keyfile option (-k) 175275970Scy<li><a href="#ntpd-logfile">ntpd logfile</a>: logfile option (-l) 176275970Scy<li><a href="#ntpd-novirtualips">ntpd novirtualips</a>: novirtualips option (-L) 177275970Scy<li><a href="#ntpd-modifymmtimer">ntpd modifymmtimer</a>: modifymmtimer option (-M) 178275970Scy<li><a href="#ntpd-nice">ntpd nice</a>: nice option (-N) 179275970Scy<li><a href="#ntpd-pidfile">ntpd pidfile</a>: pidfile option (-p) 180275970Scy<li><a href="#ntpd-priority">ntpd priority</a>: priority option (-P) 181275970Scy<li><a href="#ntpd-quit">ntpd quit</a>: quit option (-q) 182275970Scy<li><a href="#ntpd-propagationdelay">ntpd propagationdelay</a>: propagationdelay option (-r) 183275970Scy<li><a href="#ntpd-saveconfigquit">ntpd saveconfigquit</a>: saveconfigquit option 184275970Scy<li><a href="#ntpd-statsdir">ntpd statsdir</a>: statsdir option (-s) 185275970Scy<li><a href="#ntpd-trustedkey">ntpd trustedkey</a>: trustedkey option (-t) 186275970Scy<li><a href="#ntpd-user">ntpd user</a>: user option (-u) 187275970Scy<li><a href="#ntpd-updateinterval">ntpd updateinterval</a>: updateinterval option (-U) 188275970Scy<li><a href="#ntpd-wait_002dsync">ntpd wait-sync</a>: wait-sync option (-w) 189275970Scy<li><a href="#ntpd-slew">ntpd slew</a>: slew option (-x) 190275970Scy<li><a href="#ntpd-usepcc">ntpd usepcc</a>: usepcc option 191275970Scy<li><a href="#ntpd-pccfreq">ntpd pccfreq</a>: pccfreq option 192275970Scy<li><a href="#ntpd-mdns">ntpd mdns</a>: mdns option (-m) 193275970Scy<li><a href="#ntpd-config">ntpd config</a>: presetting/configuring ntpd 194275970Scy<li><a href="#ntpd-exit-status">ntpd exit status</a>: exit status 195275970Scy<li><a href="#ntpd-Usage">ntpd Usage</a>: Usage 196275970Scy<li><a href="#ntpd-Files">ntpd Files</a>: Files 197275970Scy<li><a href="#ntpd-See-Also">ntpd See Also</a>: See Also 198275970Scy<li><a href="#ntpd-Bugs">ntpd Bugs</a>: Bugs 199275970Scy<li><a href="#ntpd-Notes">ntpd Notes</a>: Notes 200275970Scy</ul> 201275970Scy 202275970Scy<div class="node"> 203275970Scy<p><hr> 204275970Scy<a name="ntpd-usage"></a>Next: <a rel="next" accesskey="n" href="#ntpd-ipv4">ntpd ipv4</a>, 205275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 206275970Scy<br> 207275970Scy</div> 208275970Scy 209275970Scy<h4 class="subsection">ntpd help/usage (<span class="option">--help</span>)</h4> 210275970Scy 211275970Scy<p><a name="index-ntpd-help-3"></a> 212275970ScyThis is the automatically generated usage text for ntpd. 213275970Scy 214275970Scy <p>The text printed is the same whether selected with the <code>help</code> option 215275970Scy(<span class="option">--help</span>) or the <code>more-help</code> option (<span class="option">--more-help</span>). <code>more-help</code> will print 216275970Scythe usage text by passing it through a pager program. 217275970Scy<code>more-help</code> is disabled on platforms without a working 218275970Scy<code>fork(2)</code> function. The <code>PAGER</code> environment variable is 219275970Scyused to select the program, defaulting to <span class="file">more</span>. Both will exit 220275970Scywith a status code of 0. 221275970Scy 222275970Scy<pre class="example">ntpd - NTP daemon program - Ver. 4.2.8-x 223275970ScyUsage: ntpd [ -<flag> [<val>] | --<name>[{=| }<val>] ]... \ 224275970Scy [ <server1> ... <serverN> ] 225275970Scy Flg Arg Option-Name Description 226275970Scy -4 no ipv4 Force IPv4 DNS name resolution 227275970Scy - prohibits the option 'ipv6' 228275970Scy -6 no ipv6 Force IPv6 DNS name resolution 229275970Scy - prohibits the option 'ipv4' 230275970Scy -a no authreq Require crypto authentication 231275970Scy - prohibits the option 'authnoreq' 232275970Scy -A no authnoreq Do not require crypto authentication 233275970Scy - prohibits the option 'authreq' 234275970Scy -b no bcastsync Allow us to sync to broadcast servers 235275970Scy -c Str configfile configuration file name 236275970Scy -d no debug-level Increase debug verbosity level 237275970Scy - may appear multiple times 238275970Scy -D Num set-debug-level Set the debug verbosity level 239275970Scy - may appear multiple times 240275970Scy -f Str driftfile frequency drift file name 241275970Scy -g no panicgate Allow the first adjustment to be Big 242275970Scy - may appear multiple times 243275970Scy -i Str jaildir Jail directory 244275970Scy -I Str interface Listen on an interface name or address 245275970Scy - may appear multiple times 246275970Scy -k Str keyfile path to symmetric keys 247275970Scy -l Str logfile path to the log file 248275970Scy -L no novirtualips Do not listen to virtual interfaces 249275970Scy -n no nofork Do not fork 250275970Scy - prohibits the option 'wait-sync' 251275970Scy -N no nice Run at high priority 252275970Scy -p Str pidfile path to the PID file 253275970Scy -P Num priority Process priority 254275970Scy -q no quit Set the time and quit 255275970Scy - prohibits these options: 256275970Scy saveconfigquit 257275970Scy wait-sync 258275970Scy -r Str propagationdelay Broadcast/propagation delay 259275970Scy Str saveconfigquit Save parsed configuration and quit 260275970Scy - prohibits these options: 261275970Scy quit 262275970Scy wait-sync 263275970Scy -s Str statsdir Statistics file location 264275970Scy -t Str trustedkey Trusted key number 265275970Scy - may appear multiple times 266275970Scy -u Str user Run as userid (or userid:groupid) 267275970Scy -U Num updateinterval interval in seconds between scans for new or dropped interfaces 268275970Scy Str var make ARG an ntp variable (RW) 269275970Scy - may appear multiple times 270275970Scy Str dvar make ARG an ntp variable (RW|DEF) 271275970Scy - may appear multiple times 272275970Scy -w Num wait-sync Seconds to wait for first clock sync 273275970Scy - prohibits these options: 274275970Scy nofork 275275970Scy quit 276275970Scy saveconfigquit 277275970Scy -x no slew Slew up to 600 seconds 278275970Scy opt version output version information and exit 279275970Scy -? no help display extended usage information and exit 280275970Scy -! no more-help extended usage information passed thru pager 281275970Scy 282275970ScyOptions are specified by doubled hyphens and their name or by a single 283275970Scyhyphen and the flag character. 284275970Scy 285275970Scy 286275970ScyThe following option preset mechanisms are supported: 287275970Scy - examining environment variables named NTPD_* 288275970Scy 289275970ScyPlease send bug reports to: <http://bugs.ntp.org, bugs@ntp.org> 290275970Scy</pre> 291275970Scy <div class="node"> 292275970Scy<p><hr> 293275970Scy<a name="ntpd-ipv4"></a>Next: <a rel="next" accesskey="n" href="#ntpd-ipv6">ntpd ipv6</a>, 294275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-usage">ntpd usage</a>, 295275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 296275970Scy<br> 297275970Scy</div> 298275970Scy 299275970Scy<h4 class="subsection">ipv4 option (-4)</h4> 300275970Scy 301275970Scy<p><a name="index-ntpd_002dipv4-4"></a> 302275970ScyThis is the “force ipv4 dns name resolution” option. 303275970Scy 304275970Scy<p class="noindent">This option has some usage constraints. It: 305275970Scy <ul> 306275970Scy<li>must not appear in combination with any of the following options: 307275970Scyipv6. 308275970Scy</ul> 309275970Scy 310275970Scy <p>Force DNS resolution of following host names on the command line 311275970Scyto the IPv4 namespace. 312275970Scy<div class="node"> 313275970Scy<p><hr> 314275970Scy<a name="ntpd-ipv6"></a>Next: <a rel="next" accesskey="n" href="#ntpd-authreq">ntpd authreq</a>, 315275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-ipv4">ntpd ipv4</a>, 316275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 317275970Scy<br> 318275970Scy</div> 319275970Scy 320275970Scy<h4 class="subsection">ipv6 option (-6)</h4> 321275970Scy 322275970Scy<p><a name="index-ntpd_002dipv6-5"></a> 323275970ScyThis is the “force ipv6 dns name resolution” option. 324275970Scy 325275970Scy<p class="noindent">This option has some usage constraints. It: 326275970Scy <ul> 327275970Scy<li>must not appear in combination with any of the following options: 328275970Scyipv4. 329275970Scy</ul> 330275970Scy 331275970Scy <p>Force DNS resolution of following host names on the command line 332275970Scyto the IPv6 namespace. 333275970Scy<div class="node"> 334275970Scy<p><hr> 335275970Scy<a name="ntpd-authreq"></a>Next: <a rel="next" accesskey="n" href="#ntpd-authnoreq">ntpd authnoreq</a>, 336275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-ipv6">ntpd ipv6</a>, 337275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 338275970Scy<br> 339275970Scy</div> 340275970Scy 341275970Scy<h4 class="subsection">authreq option (-a)</h4> 342275970Scy 343275970Scy<p><a name="index-ntpd_002dauthreq-6"></a> 344275970ScyThis is the “require crypto authentication” option. 345275970Scy 346275970Scy<p class="noindent">This option has some usage constraints. It: 347275970Scy <ul> 348275970Scy<li>must not appear in combination with any of the following options: 349275970Scyauthnoreq. 350275970Scy</ul> 351275970Scy 352275970Scy <p>Require cryptographic authentication for broadcast client, 353275970Scymulticast client and symmetric passive associations. 354275970ScyThis is the default. 355275970Scy<div class="node"> 356275970Scy<p><hr> 357275970Scy<a name="ntpd-authnoreq"></a>Next: <a rel="next" accesskey="n" href="#ntpd-configfile">ntpd configfile</a>, 358275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-authreq">ntpd authreq</a>, 359275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 360275970Scy<br> 361275970Scy</div> 362275970Scy 363275970Scy<h4 class="subsection">authnoreq option (-A)</h4> 364275970Scy 365275970Scy<p><a name="index-ntpd_002dauthnoreq-7"></a> 366275970ScyThis is the “do not require crypto authentication” option. 367275970Scy 368275970Scy<p class="noindent">This option has some usage constraints. It: 369275970Scy <ul> 370275970Scy<li>must not appear in combination with any of the following options: 371275970Scyauthreq. 372275970Scy</ul> 373275970Scy 374275970Scy <p>Do not require cryptographic authentication for broadcast client, 375275970Scymulticast client and symmetric passive associations. 376275970ScyThis is almost never a good idea. 377275970Scy<div class="node"> 378275970Scy<p><hr> 379275970Scy<a name="ntpd-configfile"></a>Next: <a rel="next" accesskey="n" href="#ntpd-driftfile">ntpd driftfile</a>, 380275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-authnoreq">ntpd authnoreq</a>, 381275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 382275970Scy<br> 383275970Scy</div> 384275970Scy 385275970Scy<h4 class="subsection">configfile option (-c)</h4> 386275970Scy 387275970Scy<p><a name="index-ntpd_002dconfigfile-8"></a> 388275970ScyThis is the “configuration file name” option. 389275970ScyThis option takes a string argument. 390275970ScyThe name and path of the configuration file, 391275970Scy<span class="file">/etc/ntp.conf</span> 392275970Scyby default. 393275970Scy<div class="node"> 394275970Scy<p><hr> 395275970Scy<a name="ntpd-driftfile"></a>Next: <a rel="next" accesskey="n" href="#ntpd-panicgate">ntpd panicgate</a>, 396275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-configfile">ntpd configfile</a>, 397275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 398275970Scy<br> 399275970Scy</div> 400275970Scy 401275970Scy<h4 class="subsection">driftfile option (-f)</h4> 402275970Scy 403275970Scy<p><a name="index-ntpd_002ddriftfile-9"></a> 404275970ScyThis is the “frequency drift file name” option. 405275970ScyThis option takes a string argument. 406275970ScyThe name and path of the frequency file, 407275970Scy<span class="file">/etc/ntp.drift</span> 408275970Scyby default. 409275970ScyThis is the same operation as the 410275970Scy<code>driftfile</code> <kbd>driftfile</kbd> 411275970Scyconfiguration specification in the 412275970Scy<span class="file">/etc/ntp.conf</span> 413275970Scyfile. 414275970Scy<div class="node"> 415275970Scy<p><hr> 416275970Scy<a name="ntpd-panicgate"></a>Next: <a rel="next" accesskey="n" href="#ntpd-jaildir">ntpd jaildir</a>, 417275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-driftfile">ntpd driftfile</a>, 418275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 419275970Scy<br> 420275970Scy</div> 421275970Scy 422275970Scy<h4 class="subsection">panicgate option (-g)</h4> 423275970Scy 424275970Scy<p><a name="index-ntpd_002dpanicgate-10"></a> 425275970ScyThis is the “allow the first adjustment to be big” option. 426275970Scy 427275970Scy<p class="noindent">This option has some usage constraints. It: 428275970Scy <ul> 429275970Scy<li>may appear an unlimited number of times. 430275970Scy</ul> 431275970Scy 432275970Scy <p>Normally, 433275970Scy<code>ntpd</code> 434275970Scyexits 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, 435275970Scy<code>ntpd</code> 436275970Scywill exit with a message to the system log. This option can be used with the 437275970Scy<code>-q</code> 438275970Scyand 439275970Scy<code>-x</code> 440275970Scyoptions. 441275970ScySee the 442275970Scy<code>tinker</code> 443275970Scyconfiguration file directive for other options. 444275970Scy<div class="node"> 445275970Scy<p><hr> 446275970Scy<a name="ntpd-jaildir"></a>Next: <a rel="next" accesskey="n" href="#ntpd-interface">ntpd interface</a>, 447275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-panicgate">ntpd panicgate</a>, 448275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 449275970Scy<br> 450275970Scy</div> 451275970Scy 452275970Scy<h4 class="subsection">jaildir option (-i)</h4> 453275970Scy 454275970Scy<p><a name="index-ntpd_002djaildir-11"></a> 455275970ScyThis is the “jail directory” option. 456275970ScyThis option takes a string argument. 457275970Scy 458275970Scy<p class="noindent">This option has some usage constraints. It: 459275970Scy <ul> 460275970Scy<li>must be compiled in by defining <code>HAVE_DROPROOT</code> during the compilation. 461275970Scy</ul> 462275970Scy 463275970Scy <p>Chroot the server to the directory 464275970Scy<kbd>jaildir</kbd> 465275970Scy. 466275970ScyThis option also implies that the server attempts to drop root privileges at startup. 467275970ScyYou may need to also specify a 468275970Scy<code>-u</code> 469275970Scyoption. 470275970ScyThis option is only available if the OS supports adjusting the clock 471275970Scywithout full root privileges. 472275970ScyThis option is supported under NetBSD (configure with 473275970Scy<code>--enable-clockctl</code>) or Linux (configure with 474275970Scy<code>--enable-linuxcaps</code>) or Solaris (configure with <code>--enable-solarisprivs</code>). 475275970Scy<div class="node"> 476275970Scy<p><hr> 477275970Scy<a name="ntpd-interface"></a>Next: <a rel="next" accesskey="n" href="#ntpd-keyfile">ntpd keyfile</a>, 478275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-jaildir">ntpd jaildir</a>, 479275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 480275970Scy<br> 481275970Scy</div> 482275970Scy 483275970Scy<h4 class="subsection">interface option (-I)</h4> 484275970Scy 485275970Scy<p><a name="index-ntpd_002dinterface-12"></a> 486275970ScyThis is the “listen on an interface name or address” option. 487275970ScyThis option takes a string argument <span class="file">iface</span>. 488275970Scy 489275970Scy<p class="noindent">This option has some usage constraints. It: 490275970Scy <ul> 491275970Scy<li>may appear an unlimited number of times. 492275970Scy</ul> 493275970Scy 494275970Scy <p>Open the network address given, or all the addresses associated with the 495275970Scygiven interface name. This option may appear multiple times. This option 496275970Scyalso implies not opening other addresses, except wildcard and localhost. 497275970ScyThis option is deprecated. Please consider using the configuration file 498275970Scy<code>interface</code> command, which is more versatile. 499275970Scy<div class="node"> 500275970Scy<p><hr> 501275970Scy<a name="ntpd-keyfile"></a>Next: <a rel="next" accesskey="n" href="#ntpd-logfile">ntpd logfile</a>, 502275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-interface">ntpd interface</a>, 503275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 504275970Scy<br> 505275970Scy</div> 506275970Scy 507275970Scy<h4 class="subsection">keyfile option (-k)</h4> 508275970Scy 509275970Scy<p><a name="index-ntpd_002dkeyfile-13"></a> 510275970ScyThis is the “path to symmetric keys” option. 511275970ScyThis option takes a string argument. 512275970ScySpecify the name and path of the symmetric key file. 513275970Scy<span class="file">/etc/ntp.keys</span> 514275970Scyis the default. 515275970ScyThis is the same operation as the 516275970Scy<code>keys</code> <kbd>keyfile</kbd> 517275970Scyconfiguration file directive. 518275970Scy<div class="node"> 519275970Scy<p><hr> 520275970Scy<a name="ntpd-logfile"></a>Next: <a rel="next" accesskey="n" href="#ntpd-novirtualips">ntpd novirtualips</a>, 521275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-keyfile">ntpd keyfile</a>, 522275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 523275970Scy<br> 524275970Scy</div> 525275970Scy 526275970Scy<h4 class="subsection">logfile option (-l)</h4> 527275970Scy 528275970Scy<p><a name="index-ntpd_002dlogfile-14"></a> 529275970ScyThis is the “path to the log file” option. 530275970ScyThis option takes a string argument. 531275970ScySpecify the name and path of the log file. 532275970ScyThe default is the system log file. 533275970ScyThis is the same operation as the 534275970Scy<code>logfile</code> <kbd>logfile</kbd> 535275970Scyconfiguration file directive. 536275970Scy<div class="node"> 537275970Scy<p><hr> 538275970Scy<a name="ntpd-novirtualips"></a>Next: <a rel="next" accesskey="n" href="#ntpd-modifymmtimer">ntpd modifymmtimer</a>, 539275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-logfile">ntpd logfile</a>, 540275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 541275970Scy<br> 542275970Scy</div> 543275970Scy 544275970Scy<h4 class="subsection">novirtualips option (-L)</h4> 545275970Scy 546275970Scy<p><a name="index-ntpd_002dnovirtualips-15"></a> 547275970ScyThis is the “do not listen to virtual interfaces” option. 548275970ScyDo not listen to virtual interfaces, defined as those with 549275970Scynames containing a colon. This option is deprecated. Please 550275970Scyconsider using the configuration file <code>interface</code> command, which 551275970Scyis more versatile. 552275970Scy<div class="node"> 553275970Scy<p><hr> 554275970Scy<a name="ntpd-modifymmtimer"></a>Next: <a rel="next" accesskey="n" href="#ntpd-nice">ntpd nice</a>, 555275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-novirtualips">ntpd novirtualips</a>, 556275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 557275970Scy<br> 558275970Scy</div> 559275970Scy 560275970Scy<h4 class="subsection">modifymmtimer option (-M)</h4> 561275970Scy 562275970Scy<p><a name="index-ntpd_002dmodifymmtimer-16"></a> 563275970ScyThis is the “modify multimedia timer (windows only)” option. 564275970Scy 565275970Scy<p class="noindent">This option has some usage constraints. It: 566275970Scy <ul> 567275970Scy<li>must be compiled in by defining <code>SYS_WINNT</code> during the compilation. 568275970Scy</ul> 569275970Scy 570275970Scy <p>Set the Windows Multimedia Timer to highest resolution. This 571275970Scyensures the resolution does not change while ntpd is running, 572275970Scyavoiding timekeeping glitches associated with changes. 573275970Scy<div class="node"> 574275970Scy<p><hr> 575275970Scy<a name="ntpd-nice"></a>Next: <a rel="next" accesskey="n" href="#ntpd-pidfile">ntpd pidfile</a>, 576275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-modifymmtimer">ntpd modifymmtimer</a>, 577275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 578275970Scy<br> 579275970Scy</div> 580275970Scy 581275970Scy<h4 class="subsection">nice option (-N)</h4> 582275970Scy 583275970Scy<p><a name="index-ntpd_002dnice-17"></a> 584275970ScyThis is the “run at high priority” option. 585275970ScyTo the extent permitted by the operating system, run 586275970Scy<code>ntpd</code> 587275970Scyat the highest priority. 588275970Scy<div class="node"> 589275970Scy<p><hr> 590275970Scy<a name="ntpd-pidfile"></a>Next: <a rel="next" accesskey="n" href="#ntpd-priority">ntpd priority</a>, 591275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-nice">ntpd nice</a>, 592275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 593275970Scy<br> 594275970Scy</div> 595275970Scy 596275970Scy<h4 class="subsection">pidfile option (-p)</h4> 597275970Scy 598275970Scy<p><a name="index-ntpd_002dpidfile-18"></a> 599275970ScyThis is the “path to the pid file” option. 600275970ScyThis option takes a string argument. 601275970ScySpecify the name and path of the file used to record 602275970Scy<code>ntpd</code>'s 603275970Scyprocess ID. 604275970ScyThis is the same operation as the 605275970Scy<code>pidfile</code> <kbd>pidfile</kbd> 606275970Scyconfiguration file directive. 607275970Scy<div class="node"> 608275970Scy<p><hr> 609275970Scy<a name="ntpd-priority"></a>Next: <a rel="next" accesskey="n" href="#ntpd-quit">ntpd quit</a>, 610275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-pidfile">ntpd pidfile</a>, 611275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 612275970Scy<br> 613275970Scy</div> 614275970Scy 615275970Scy<h4 class="subsection">priority option (-P)</h4> 616275970Scy 617275970Scy<p><a name="index-ntpd_002dpriority-19"></a> 618275970ScyThis is the “process priority” option. 619275970ScyThis option takes a number argument. 620275970ScyTo the extent permitted by the operating system, run 621275970Scy<code>ntpd</code> 622275970Scyat the specified 623275970Scy<code>sched_setscheduler(SCHED_FIFO)</code> 624275970Scypriority. 625275970Scy<div class="node"> 626275970Scy<p><hr> 627275970Scy<a name="ntpd-quit"></a>Next: <a rel="next" accesskey="n" href="#ntpd-propagationdelay">ntpd propagationdelay</a>, 628275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-priority">ntpd priority</a>, 629275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 630275970Scy<br> 631275970Scy</div> 632275970Scy 633275970Scy<h4 class="subsection">quit option (-q)</h4> 634275970Scy 635275970Scy<p><a name="index-ntpd_002dquit-20"></a> 636275970ScyThis is the “set the time and quit” option. 637275970Scy 638275970Scy<p class="noindent">This option has some usage constraints. It: 639275970Scy <ul> 640275970Scy<li>must not appear in combination with any of the following options: 641275970Scysaveconfigquit, wait-sync. 642275970Scy</ul> 643275970Scy 644275970Scy <p><code>ntpd</code> 645275970Scywill not daemonize and will exit after the clock is first 646275970Scysynchronized. This behavior mimics that of the 647275970Scy<code>ntpdate</code> 648275970Scyprogram, which will soon be replaced with a shell script. 649275970ScyThe 650275970Scy<code>-g</code> 651275970Scyand 652275970Scy<code>-x</code> 653275970Scyoptions can be used with this option. 654275970ScyNote: The kernel time discipline is disabled with this option. 655275970Scy<div class="node"> 656275970Scy<p><hr> 657275970Scy<a name="ntpd-propagationdelay"></a>Next: <a rel="next" accesskey="n" href="#ntpd-saveconfigquit">ntpd saveconfigquit</a>, 658275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-quit">ntpd quit</a>, 659275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 660275970Scy<br> 661275970Scy</div> 662275970Scy 663275970Scy<h4 class="subsection">propagationdelay option (-r)</h4> 664275970Scy 665275970Scy<p><a name="index-ntpd_002dpropagationdelay-21"></a> 666275970ScyThis is the “broadcast/propagation delay” option. 667275970ScyThis option takes a string argument. 668275970ScySpecify 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. 669275970Scy<div class="node"> 670275970Scy<p><hr> 671275970Scy<a name="ntpd-saveconfigquit"></a>Next: <a rel="next" accesskey="n" href="#ntpd-statsdir">ntpd statsdir</a>, 672275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-propagationdelay">ntpd propagationdelay</a>, 673275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 674275970Scy<br> 675275970Scy</div> 676275970Scy 677275970Scy<h4 class="subsection">saveconfigquit option</h4> 678275970Scy 679275970Scy<p><a name="index-ntpd_002dsaveconfigquit-22"></a> 680275970ScyThis is the “save parsed configuration and quit” option. 681275970ScyThis option takes a string argument. 682275970Scy 683275970Scy<p class="noindent">This option has some usage constraints. It: 684275970Scy <ul> 685275970Scy<li>must be compiled in by defining <code>SAVECONFIG</code> during the compilation. 686275970Scy<li>must not appear in combination with any of the following options: 687275970Scyquit, wait-sync. 688275970Scy</ul> 689275970Scy 690275970Scy <p>Cause <code>ntpd</code> to parse its startup configuration file and save an 691275970Scyequivalent to the given filename and exit. This option was 692275970Scydesigned for automated testing. 693275970Scy<div class="node"> 694275970Scy<p><hr> 695275970Scy<a name="ntpd-statsdir"></a>Next: <a rel="next" accesskey="n" href="#ntpd-trustedkey">ntpd trustedkey</a>, 696275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-saveconfigquit">ntpd saveconfigquit</a>, 697275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 698275970Scy<br> 699275970Scy</div> 700275970Scy 701275970Scy<h4 class="subsection">statsdir option (-s)</h4> 702275970Scy 703275970Scy<p><a name="index-ntpd_002dstatsdir-23"></a> 704275970ScyThis is the “statistics file location” option. 705275970ScyThis option takes a string argument. 706275970ScySpecify the directory path for files created by the statistics facility. 707275970ScyThis is the same operation as the 708275970Scy<code>statsdir</code> <kbd>statsdir</kbd> 709275970Scyconfiguration file directive. 710275970Scy<div class="node"> 711275970Scy<p><hr> 712275970Scy<a name="ntpd-trustedkey"></a>Next: <a rel="next" accesskey="n" href="#ntpd-user">ntpd user</a>, 713275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-statsdir">ntpd statsdir</a>, 714275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 715275970Scy<br> 716275970Scy</div> 717275970Scy 718275970Scy<h4 class="subsection">trustedkey option (-t)</h4> 719275970Scy 720275970Scy<p><a name="index-ntpd_002dtrustedkey-24"></a> 721275970ScyThis is the “trusted key number” option. 722275970ScyThis option takes a string argument <span class="file">tkey</span>. 723275970Scy 724275970Scy<p class="noindent">This option has some usage constraints. It: 725275970Scy <ul> 726275970Scy<li>may appear an unlimited number of times. 727275970Scy</ul> 728275970Scy 729275970Scy <p>Add the specified key number to the trusted key list. 730275970Scy<div class="node"> 731275970Scy<p><hr> 732275970Scy<a name="ntpd-user"></a>Next: <a rel="next" accesskey="n" href="#ntpd-updateinterval">ntpd updateinterval</a>, 733275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-trustedkey">ntpd trustedkey</a>, 734275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 735275970Scy<br> 736275970Scy</div> 737275970Scy 738275970Scy<h4 class="subsection">user option (-u)</h4> 739275970Scy 740275970Scy<p><a name="index-ntpd_002duser-25"></a> 741275970ScyThis is the “run as userid (or userid:groupid)” option. 742275970ScyThis option takes a string argument. 743275970Scy 744275970Scy<p class="noindent">This option has some usage constraints. It: 745275970Scy <ul> 746275970Scy<li>must be compiled in by defining <code>HAVE_DROPROOT</code> during the compilation. 747275970Scy</ul> 748275970Scy 749275970Scy <p>Specify a user, and optionally a group, to switch to. 750275970ScyThis option is only available if the OS supports adjusting the clock 751275970Scywithout full root privileges. 752275970ScyThis option is supported under NetBSD (configure with 753275970Scy<code>--enable-clockctl</code>) or Linux (configure with 754275970Scy<code>--enable-linuxcaps</code>) or Solaris (configure with <code>--enable-solarisprivs</code>). 755275970Scy<div class="node"> 756275970Scy<p><hr> 757275970Scy<a name="ntpd-updateinterval"></a>Next: <a rel="next" accesskey="n" href="#ntpd-wait_002dsync">ntpd wait-sync</a>, 758275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-user">ntpd user</a>, 759275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 760275970Scy<br> 761275970Scy</div> 762275970Scy 763275970Scy<h4 class="subsection">updateinterval option (-U)</h4> 764275970Scy 765275970Scy<p><a name="index-ntpd_002dupdateinterval-26"></a> 766275970ScyThis is the “interval in seconds between scans for new or dropped interfaces” option. 767275970ScyThis option takes a number argument. 768275970ScyGive the time in seconds between two scans for new or dropped interfaces. 769275970ScyFor systems with routing socket support the scans will be performed shortly after the interface change 770275970Scyhas been detected by the system. 771275970ScyUse 0 to disable scanning. 60 seconds is the minimum time between scans. 772275970Scy<div class="node"> 773275970Scy<p><hr> 774275970Scy<a name="ntpd-wait_002dsync"></a>Next: <a rel="next" accesskey="n" href="#ntpd-slew">ntpd slew</a>, 775275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-updateinterval">ntpd updateinterval</a>, 776275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 777275970Scy<br> 778275970Scy</div> 779275970Scy 780275970Scy<h4 class="subsection">wait-sync option (-w)</h4> 781275970Scy 782275970Scy<p><a name="index-ntpd_002dwait_002dsync-27"></a> 783275970ScyThis is the “seconds to wait for first clock sync” option. 784275970ScyThis option takes a number argument. 785275970Scy 786275970Scy<p class="noindent">This option has some usage constraints. It: 787275970Scy <ul> 788275970Scy<li>must be compiled in by defining <code>HAVE_WORKING_FORK</code> during the compilation. 789275970Scy<li>must not appear in combination with any of the following options: 790275970Scynofork, quit, saveconfigquit. 791275970Scy</ul> 792275970Scy 793275970Scy <p>If greater than zero, alters <code>ntpd</code>'s behavior when forking to 794275970Scydaemonize. Instead of exiting with status 0 immediately after 795275970Scythe fork, the parent waits up to the specified number of 796275970Scyseconds for the child to first synchronize the clock. The exit 797275970Scystatus is zero (success) if the clock was synchronized, 798275970Scyotherwise it is <code>ETIMEDOUT</code>. 799275970ScyThis provides the option for a script starting <code>ntpd</code> to easily 800275970Scywait for the first set of the clock before proceeding. 801275970Scy<div class="node"> 802275970Scy<p><hr> 803275970Scy<a name="ntpd-slew"></a>Next: <a rel="next" accesskey="n" href="#ntpd-usepcc">ntpd usepcc</a>, 804275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-wait_002dsync">ntpd wait-sync</a>, 805275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 806275970Scy<br> 807275970Scy</div> 808275970Scy 809275970Scy<h4 class="subsection">slew option (-x)</h4> 810275970Scy 811275970Scy<p><a name="index-ntpd_002dslew-28"></a> 812275970ScyThis is the “slew up to 600 seconds” option. 813275970ScyNormally, 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. 814275970ScyThis option sets the threshold to 600 s, which is well within the accuracy window to set the clock manually. 815275970ScyNote: 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. 816275970ScyThus, an adjustment as much as 600 s will take almost 14 days to complete. 817275970ScyThis option can be used with the 818275970Scy<code>-g</code> 819275970Scyand 820275970Scy<code>-q</code> 821275970Scyoptions. 822275970ScySee the 823275970Scy<code>tinker</code> 824275970Scyconfiguration file directive for other options. 825275970ScyNote: The kernel time discipline is disabled with this option. 826275970Scy<div class="node"> 827275970Scy<p><hr> 828275970Scy<a name="ntpd-usepcc"></a>Next: <a rel="next" accesskey="n" href="#ntpd-pccfreq">ntpd pccfreq</a>, 829275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-slew">ntpd slew</a>, 830275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 831275970Scy<br> 832275970Scy</div> 833275970Scy 834275970Scy<h4 class="subsection">usepcc option</h4> 835275970Scy 836275970Scy<p><a name="index-ntpd_002dusepcc-29"></a> 837275970ScyThis is the “use cpu cycle counter (windows only)” option. 838275970Scy 839275970Scy<p class="noindent">This option has some usage constraints. It: 840275970Scy <ul> 841275970Scy<li>must be compiled in by defining <code>SYS_WINNT</code> during the compilation. 842275970Scy</ul> 843275970Scy 844275970Scy <p>Attempt to substitute the CPU counter for <code>QueryPerformanceCounter</code>. 845275970ScyThe CPU counter and <code>QueryPerformanceCounter</code> are compared, and if 846275970Scythey have the same frequency, the CPU counter (RDTSC on x86) is 847275970Scyused directly, saving the overhead of a system call. 848275970Scy<div class="node"> 849275970Scy<p><hr> 850275970Scy<a name="ntpd-pccfreq"></a>Next: <a rel="next" accesskey="n" href="#ntpd-mdns">ntpd mdns</a>, 851275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-usepcc">ntpd usepcc</a>, 852275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 853275970Scy<br> 854275970Scy</div> 855275970Scy 856275970Scy<h4 class="subsection">pccfreq option</h4> 857275970Scy 858275970Scy<p><a name="index-ntpd_002dpccfreq-30"></a> 859275970ScyThis is the “force cpu cycle counter use (windows only)” option. 860275970ScyThis option takes a string argument. 861275970Scy 862275970Scy<p class="noindent">This option has some usage constraints. It: 863275970Scy <ul> 864275970Scy<li>must be compiled in by defining <code>SYS_WINNT</code> during the compilation. 865275970Scy</ul> 866275970Scy 867275970Scy <p>Force substitution the CPU counter for <code>QueryPerformanceCounter</code>. 868275970ScyThe CPU counter (RDTSC on x86) is used unconditionally with the 869275970Scygiven frequency (in Hz). 870275970Scy<div class="node"> 871275970Scy<p><hr> 872275970Scy<a name="ntpd-mdns"></a>Next: <a rel="next" accesskey="n" href="#ntpd-config">ntpd config</a>, 873275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-pccfreq">ntpd pccfreq</a>, 874275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 875275970Scy<br> 876275970Scy</div> 877275970Scy 878275970Scy<h4 class="subsection">mdns option (-m)</h4> 879275970Scy 880275970Scy<p><a name="index-ntpd_002dmdns-31"></a> 881275970ScyThis is the “register with mdns as a ntp server” option. 882275970Scy 883275970Scy<p class="noindent">This option has some usage constraints. It: 884275970Scy <ul> 885275970Scy<li>must be compiled in by defining <code>HAVE_DNSREGISTRATION</code> during the compilation. 886275970Scy</ul> 887275970Scy 888275970Scy <p>Registers as an NTP server with the local mDNS server which allows 889275970Scythe server to be discovered via mDNS client lookup. 890275970Scy 891275970Scy<div class="node"> 892275970Scy<p><hr> 893275970Scy<a name="ntpd-config"></a>Next: <a rel="next" accesskey="n" href="#ntpd-exit-status">ntpd exit status</a>, 894275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-mdns">ntpd mdns</a>, 895275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 896275970Scy<br> 897275970Scy</div> 898275970Scy 899275970Scy<h4 class="subsection">presetting/configuring ntpd</h4> 900275970Scy 901275970Scy<p>Any option that is not marked as <i>not presettable</i> may be preset by 902275970Scyloading values from environment variables named <code>NTPD</code> and <code>NTPD_<OPTION_NAME></code>. <code><OPTION_NAME></code> must be one of 903275970Scythe options listed above in upper case and segmented with underscores. 904275970ScyThe <code>NTPD</code> variable will be tokenized and parsed like 905275970Scythe command line. The remaining variables are tested for existence and their 906275970Scyvalues are treated like option arguments. 907275970Scy 908275970Scy <p>The command line options relating to configuration and/or usage help are: 909275970Scy 910275970Scy<h5 class="subsubheading">version (-)</h5> 911275970Scy 912275970Scy<p>Print the program version to standard out, optionally with licensing 913275970Scyinformation, then exit 0. The optional argument specifies how much licensing 914275970Scydetail to provide. The default is to print just the version. The licensing infomation may be selected with an option argument. 915275970ScyOnly the first letter of the argument is examined: 916275970Scy 917275970Scy <dl> 918275970Scy<dt><span class="samp">version</span><dd>Only print the version. This is the default. 919275970Scy<br><dt><span class="samp">copyright</span><dd>Name the copyright usage licensing terms. 920275970Scy<br><dt><span class="samp">verbose</span><dd>Print the full copyright usage licensing terms. 921275970Scy</dl> 922275970Scy 923275970Scy<div class="node"> 924275970Scy<p><hr> 925275970Scy<a name="ntpd-exit-status"></a>Next: <a rel="next" accesskey="n" href="#ntpd-Usage">ntpd Usage</a>, 926275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-config">ntpd config</a>, 927275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 928275970Scy<br> 929275970Scy</div> 930275970Scy 931275970Scy<h4 class="subsection">ntpd exit status</h4> 932275970Scy 933275970Scy<p>One of the following exit values will be returned: 934275970Scy <dl> 935275970Scy<dt><span class="samp">0 (EXIT_SUCCESS)</span><dd>Successful program execution. 936275970Scy<br><dt><span class="samp">1 (EXIT_FAILURE)</span><dd>The operation failed or the command syntax was not valid. 937275970Scy</dl> 938275970Scy <div class="node"> 939275970Scy<p><hr> 940275970Scy<a name="ntpd-Usage"></a>Next: <a rel="next" accesskey="n" href="#ntpd-Files">ntpd Files</a>, 941275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-exit-status">ntpd exit status</a>, 942275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 943275970Scy<br> 944275970Scy</div> 945275970Scy 946275970Scy<h4 class="subsection">ntpd Usage</h4> 947275970Scy 948275970Scy<div class="node"> 949275970Scy<p><hr> 950275970Scy<a name="ntpd-Files"></a>Next: <a rel="next" accesskey="n" href="#ntpd-See-Also">ntpd See Also</a>, 951275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-Usage">ntpd Usage</a>, 952275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 953275970Scy<br> 954275970Scy</div> 955275970Scy 956275970Scy<h4 class="subsection">ntpd Files</h4> 957275970Scy 958275970Scy<div class="node"> 959275970Scy<p><hr> 960275970Scy<a name="ntpd-See-Also"></a>Next: <a rel="next" accesskey="n" href="#ntpd-Bugs">ntpd Bugs</a>, 961275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-Files">ntpd Files</a>, 962275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 963275970Scy<br> 964275970Scy</div> 965275970Scy 966275970Scy<h4 class="subsection">ntpd See Also</h4> 967275970Scy 968275970Scy<div class="node"> 969275970Scy<p><hr> 970275970Scy<a name="ntpd-Bugs"></a>Next: <a rel="next" accesskey="n" href="#ntpd-Notes">ntpd Notes</a>, 971275970ScyPrevious: <a rel="previous" accesskey="p" href="#ntpd-See-Also">ntpd See Also</a>, 972275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 973275970Scy<br> 974275970Scy</div> 975275970Scy 976275970Scy<h4 class="subsection">ntpd Bugs</h4> 977275970Scy 978275970Scy<div class="node"> 979275970Scy<p><hr> 980275970Scy<a name="ntpd-Notes"></a>Previous: <a rel="previous" accesskey="p" href="#ntpd-Bugs">ntpd Bugs</a>, 981275970ScyUp: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 982275970Scy<br> 983275970Scy</div> 984275970Scy 985275970Scy<h4 class="subsection">ntpd Notes</h4> 986275970Scy 987275970Scy<div class="node"> 988275970Scy<p><hr> 989275970Scy<a name="Usage"></a> 990275970Scy<br> 991275970Scy</div> 992275970Scy 993275970Scy<!-- node-name, next, previous, up --> 994275970Scy<h3 class="section">Usage</h3> 995275970Scy 996