1<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 2<html> 3<!-- Created by GNU Texinfo 6.6, http://www.gnu.org/software/texinfo/ --> 4<head> 5<meta http-equiv="Content-Type" content="text/html; charset=utf-8"> 6<title>ntpd: Network Time Protocol (NTP) Daemon User’s Manual</title> 7 8<meta name="description" content="ntpd: Network Time Protocol (NTP) Daemon User’s Manual"> 9<meta name="keywords" content="ntpd: Network Time Protocol (NTP) Daemon User’s Manual"> 10<meta name="resource-type" content="document"> 11<meta name="distribution" content="global"> 12<meta name="Generator" content="makeinfo"> 13<link href="#Top" rel="start" title="Top"> 14<link href="dir.html#Top" rel="up" title="(dir)"> 15<style type="text/css"> 16<!-- 17a.summary-letter {text-decoration: none} 18blockquote.indentedblock {margin-right: 0em} 19div.display {margin-left: 3.2em} 20div.example {margin-left: 3.2em} 21div.lisp {margin-left: 3.2em} 22kbd {font-style: oblique} 23pre.display {font-family: inherit} 24pre.format {font-family: inherit} 25pre.menu-comment {font-family: serif} 26pre.menu-preformatted {font-family: serif} 27span.nolinebreak {white-space: nowrap} 28span.roman {font-family: initial; font-weight: normal} 29span.sansserif {font-family: sans-serif; font-weight: normal} 30ul.no-bullet {list-style: none} 31--> 32</style> 33 34 35</head> 36 37<body lang="en"> 38<h1 class="settitle" align="center">ntpd: Network Time Protocol (NTP) Daemon User’s Manual</h1> 39 40 41 42 43 44<span id="Top"></span><div class="header"> 45<p> 46Next: <a href="#ntpd-Description" accesskey="n" rel="next">ntpd Description</a>, Previous: <a href="dir.html#Top" accesskey="p" rel="prev">(dir)</a>, Up: <a href="dir.html#Top" accesskey="u" rel="up">(dir)</a> </p> 47</div> 48<span id="ntpd_003a-Network-Time-Protocol-_0028NTP_0029-Daemon-User-Manual"></span><h1 class="top">ntpd: Network Time Protocol (NTP) Daemon User Manual</h1> 49 50<p>The <code>ntpd</code> program is an operating system daemon that synchronizes the 51system clock to remote NTP time servers or local reference clocks. 52It is a complete implementation of NTP version 4 defined by RFC-5905, but 53also retains compatible with version 3 defined by RFC-1305 and versions 541 and 2, defined by RFC-1059 and RFC-1119, respectively. 55The program can operate in any of several modes, including client/server, 56symmetric and broadcast modes, and with both symmetric-key and public-key 57cryptography. 58</p> 59<p>This document applies to version 4.2.8p18 of <code>ntpd</code>. 60</p> 61<span id="SEC_Overview"></span> 62<h2 class="shortcontents-heading">Short Table of Contents</h2> 63 64<div class="shortcontents"> 65<ul class="no-bullet"> 66<li><a id="stoc-Description" href="#toc-Description">1 Description</a></li> 67</ul> 68</div> 69 70 71<table class="menu" border="0" cellspacing="0"> 72<tr><td align="left" valign="top">• <a href="#ntpd-Description" accesskey="1">ntpd Description</a></td><td> </td><td align="left" valign="top">Description 73</td></tr> 74<tr><td align="left" valign="top">• <a href="#ntpd-Invocation" accesskey="2">ntpd Invocation</a></td><td> </td><td align="left" valign="top">Invoking ntpd 75</td></tr> 76<tr><td align="left" valign="top">• <a href="#Usage" accesskey="3">Usage</a></td><td> </td><td align="left" valign="top">Usage 77</td></tr> 78</table> 79 80<hr> 81<span id="ntpd-Description"></span><div class="header"> 82<p> 83Next: <a href="#ntpd-Invocation" accesskey="n" rel="next">ntpd Invocation</a>, Up: <a href="#Top" accesskey="u" rel="up">Top</a> </p> 84</div> 85<span id="Description"></span><h2 class="chapter">1 Description</h2> 86 87<p>The <code>ntpd</code> program ordinarily requires 88a configuration file described at ‘ntp.conf’. 89This configuration file contains configuration commands described on 90the pages listed above. 91However a client can discover remote servers and configure them 92automatically. 93This makes it possible to deploy a fleet of workstations without 94specifying configuration details specific to the local environment. 95</p> 96<p>The <code>ntpd</code> program normally operates continuously while adjusting the 97system time and frequency, but in some cases this might not be 98practical. 99With the <code>-q</code> option <code>ntpd</code> operates as in continuous mode, but 100exits just after setting the clock for the first time. 101Most applications will probably want to specify the <code>iburst</code> 102option with the <code>server</code> command. 103With this option an initial volley of messages is exchanged to 104groom the data and set the clock in about ten seconds’ time. 105If nothing is heard after a few minutes’ time, 106the daemon times out and exits without setting the clock. 107</p> 108<table class="menu" border="0" cellspacing="0"> 109<tr><td align="left" valign="top">• <a href="#ntpd-Invocation" accesskey="1">Invoking ntpd</a></td><td> </td><td align="left" valign="top"> 110</td></tr> 111<tr><td align="left" valign="top">• <a href="#Usage" accesskey="2">Usage</a></td><td> </td><td align="left" valign="top"> 112</td></tr> 113</table> 114 115<hr> 116<span id="ntpd-Invocation"></span><div class="header"> 117<p> 118Next: <a href="#Usage" accesskey="n" rel="next">Usage</a>, Previous: <a href="#ntpd-Description" accesskey="p" rel="prev">ntpd Description</a>, Up: <a href="#ntpd-Description" accesskey="u" rel="up">ntpd Description</a> </p> 119</div> 120<span id="Invoking-ntpd"></span><h3 class="section">1.1 Invoking ntpd</h3> 121<span id="index-ntpd"></span> 122<span id="index-NTP-daemon-program"></span> 123 124 125 126<p>The 127<code>ntpd</code> 128utility is an operating system daemon which sets 129and maintains the system time of day in synchronism with Internet 130standard time servers. 131It is a complete implementation of the 132Network Time Protocol (NTP) version 4, as defined by RFC-5905, 133but also retains compatibility with 134version 3, as defined by RFC-1305, and versions 1 135and 2, as defined by RFC-1059 and RFC-1119, respectively. 136</p> 137<p>The 138<code>ntpd</code> 139utility does most computations in 64-bit floating point 140arithmetic and does relatively clumsy 64-bit fixed point operations 141only when necessary to preserve the ultimate precision, about 232 142picoseconds. 143While the ultimate precision is not achievable with 144ordinary workstations and networks of today, it may be required 145with future gigahertz CPU clocks and gigabit LANs. 146</p> 147<p>Ordinarily, 148<code>ntpd</code> 149reads the 150<code>ntp.conf(5)</code> 151configuration file at startup time in order to determine the 152synchronization sources and operating modes. 153It is also possible to 154specify a working, although limited, configuration entirely on the 155command line, obviating the need for a configuration file. 156This may 157be particularly useful when the local host is to be configured as a 158broadcast/multicast client, with all peers being determined by 159listening to broadcasts at run time. 160</p> 161<p>If NetInfo support is built into 162<code>ntpd</code> 163then 164<code>ntpd</code> 165will attempt to read its configuration from the 166NetInfo if the default 167<code>ntp.conf(5)</code> 168file cannot be read and no file is 169specified by the 170<code>-c</code> 171option. 172</p> 173<p>Various internal 174<code>ntpd</code> 175variables can be displayed and 176configuration options altered while the 177<code>ntpd</code> 178is running 179using the 180<code>ntpq(1ntpqmdoc)</code> 181and 182<code>ntpdc(1ntpdcmdoc)</code> 183utility programs. 184</p> 185<p>When 186<code>ntpd</code> 187starts it looks at the value of 188<code>umask(2)</code>, 189and if zero 190<code>ntpd</code> 191will set the 192<code>umask(2)</code> 193to 022. 194</p> 195<p>This section was generated by <strong>AutoGen</strong>, 196using the <code>agtexi-cmd</code> template and the option descriptions for the <code>ntpd</code> program. 197This software is released under the NTP license, <http://ntp.org/license>. 198</p> 199<table class="menu" border="0" cellspacing="0"> 200<tr><td align="left" valign="top">• <a href="#ntpd-usage" accesskey="1">ntpd usage</a></td><td> </td><td align="left" valign="top">ntpd help/usage (<samp>--help</samp>) 201</td></tr> 202<tr><td align="left" valign="top">• <a href="#ntpd-ipv4" accesskey="2">ntpd ipv4</a></td><td> </td><td align="left" valign="top">ipv4 option (-4) 203</td></tr> 204<tr><td align="left" valign="top">• <a href="#ntpd-ipv6" accesskey="3">ntpd ipv6</a></td><td> </td><td align="left" valign="top">ipv6 option (-6) 205</td></tr> 206<tr><td align="left" valign="top">• <a href="#ntpd-authreq" accesskey="4">ntpd authreq</a></td><td> </td><td align="left" valign="top">authreq option (-a) 207</td></tr> 208<tr><td align="left" valign="top">• <a href="#ntpd-authnoreq" accesskey="5">ntpd authnoreq</a></td><td> </td><td align="left" valign="top">authnoreq option (-A) 209</td></tr> 210<tr><td align="left" valign="top">• <a href="#ntpd-configfile" accesskey="6">ntpd configfile</a></td><td> </td><td align="left" valign="top">configfile option (-c) 211</td></tr> 212<tr><td align="left" valign="top">• <a href="#ntpd-driftfile" accesskey="7">ntpd driftfile</a></td><td> </td><td align="left" valign="top">driftfile option (-f) 213</td></tr> 214<tr><td align="left" valign="top">• <a href="#ntpd-panicgate" accesskey="8">ntpd panicgate</a></td><td> </td><td align="left" valign="top">panicgate option (-g) 215</td></tr> 216<tr><td align="left" valign="top">• <a href="#ntpd-force_002dstep_002donce" accesskey="9">ntpd force-step-once</a></td><td> </td><td align="left" valign="top">force-step-once option (-G) 217</td></tr> 218<tr><td align="left" valign="top">• <a href="#ntpd-jaildir">ntpd jaildir</a></td><td> </td><td align="left" valign="top">jaildir option (-i) 219</td></tr> 220<tr><td align="left" valign="top">• <a href="#ntpd-interface">ntpd interface</a></td><td> </td><td align="left" valign="top">interface option (-I) 221</td></tr> 222<tr><td align="left" valign="top">• <a href="#ntpd-keyfile">ntpd keyfile</a></td><td> </td><td align="left" valign="top">keyfile option (-k) 223</td></tr> 224<tr><td align="left" valign="top">• <a href="#ntpd-logfile">ntpd logfile</a></td><td> </td><td align="left" valign="top">logfile option (-l) 225</td></tr> 226<tr><td align="left" valign="top">• <a href="#ntpd-novirtualips">ntpd novirtualips</a></td><td> </td><td align="left" valign="top">novirtualips option (-L) 227</td></tr> 228<tr><td align="left" valign="top">• <a href="#ntpd-modifymmtimer">ntpd modifymmtimer</a></td><td> </td><td align="left" valign="top">modifymmtimer option (-M) 229</td></tr> 230<tr><td align="left" valign="top">• <a href="#ntpd-nice">ntpd nice</a></td><td> </td><td align="left" valign="top">nice option (-N) 231</td></tr> 232<tr><td align="left" valign="top">• <a href="#ntpd-pidfile">ntpd pidfile</a></td><td> </td><td align="left" valign="top">pidfile option (-p) 233</td></tr> 234<tr><td align="left" valign="top">• <a href="#ntpd-priority">ntpd priority</a></td><td> </td><td align="left" valign="top">priority option (-P) 235</td></tr> 236<tr><td align="left" valign="top">• <a href="#ntpd-quit">ntpd quit</a></td><td> </td><td align="left" valign="top">quit option (-q) 237</td></tr> 238<tr><td align="left" valign="top">• <a href="#ntpd-propagationdelay">ntpd propagationdelay</a></td><td> </td><td align="left" valign="top">propagationdelay option (-r) 239</td></tr> 240<tr><td align="left" valign="top">• <a href="#ntpd-saveconfigquit">ntpd saveconfigquit</a></td><td> </td><td align="left" valign="top">saveconfigquit option 241</td></tr> 242<tr><td align="left" valign="top">• <a href="#ntpd-statsdir">ntpd statsdir</a></td><td> </td><td align="left" valign="top">statsdir option (-s) 243</td></tr> 244<tr><td align="left" valign="top">• <a href="#ntpd-trustedkey">ntpd trustedkey</a></td><td> </td><td align="left" valign="top">trustedkey option (-t) 245</td></tr> 246<tr><td align="left" valign="top">• <a href="#ntpd-user">ntpd user</a></td><td> </td><td align="left" valign="top">user option (-u) 247</td></tr> 248<tr><td align="left" valign="top">• <a href="#ntpd-updateinterval">ntpd updateinterval</a></td><td> </td><td align="left" valign="top">updateinterval option (-U) 249</td></tr> 250<tr><td align="left" valign="top">• <a href="#ntpd-wait_002dsync">ntpd wait-sync</a></td><td> </td><td align="left" valign="top">wait-sync option (-w) 251</td></tr> 252<tr><td align="left" valign="top">• <a href="#ntpd-slew">ntpd slew</a></td><td> </td><td align="left" valign="top">slew option (-x) 253</td></tr> 254<tr><td align="left" valign="top">• <a href="#ntpd-usepcc">ntpd usepcc</a></td><td> </td><td align="left" valign="top">usepcc option 255</td></tr> 256<tr><td align="left" valign="top">• <a href="#ntpd-pccfreq">ntpd pccfreq</a></td><td> </td><td align="left" valign="top">pccfreq option 257</td></tr> 258<tr><td align="left" valign="top">• <a href="#ntpd-mdns">ntpd mdns</a></td><td> </td><td align="left" valign="top">mdns option (-m) 259</td></tr> 260<tr><td align="left" valign="top">• <a href="#ntpd-config">ntpd config</a></td><td> </td><td align="left" valign="top">presetting/configuring ntpd 261</td></tr> 262<tr><td align="left" valign="top">• <a href="#ntpd-exit-status">ntpd exit status</a></td><td> </td><td align="left" valign="top">exit status 263</td></tr> 264<tr><td align="left" valign="top">• <a href="#ntpd-Usage">ntpd Usage</a></td><td> </td><td align="left" valign="top">Usage 265</td></tr> 266<tr><td align="left" valign="top">• <a href="#ntpd-Files">ntpd Files</a></td><td> </td><td align="left" valign="top">Files 267</td></tr> 268<tr><td align="left" valign="top">• <a href="#ntpd-See-Also">ntpd See Also</a></td><td> </td><td align="left" valign="top">See Also 269</td></tr> 270<tr><td align="left" valign="top">• <a href="#ntpd-Bugs">ntpd Bugs</a></td><td> </td><td align="left" valign="top">Bugs 271</td></tr> 272<tr><td align="left" valign="top">• <a href="#ntpd-Notes">ntpd Notes</a></td><td> </td><td align="left" valign="top">Notes 273</td></tr> 274</table> 275 276<hr> 277<span id="ntpd-usage"></span><div class="header"> 278<p> 279Next: <a href="#ntpd-ipv4" accesskey="n" rel="next">ntpd ipv4</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 280</div> 281<span id="ntpd-help_002fusage-_0028_002d_002dhelp_0029"></span><h4 class="subsection">1.1.1 ntpd help/usage (<samp>--help</samp>)</h4> 282<span id="index-ntpd-help"></span> 283 284<p>This is the automatically generated usage text for ntpd. 285</p> 286<p>The text printed is the same whether selected with the <code>help</code> option 287(<samp>--help</samp>) or the <code>more-help</code> option (<samp>--more-help</samp>). <code>more-help</code> will print 288the usage text by passing it through a pager program. 289<code>more-help</code> is disabled on platforms without a working 290<code>fork(2)</code> function. The <code>PAGER</code> environment variable is 291used to select the program, defaulting to <samp>more</samp>. Both will exit 292with a status code of 0. 293</p> 294<div class="example"> 295<pre class="example">ntpd - NTP daemon program - Ver. 4.2.8p18 296Usage: ntpd [ -<flag> [<val>] | --<name>[{=| }<val>] ]... \ 297 [ <server1> ... <serverN> ] 298 Flg Arg Option-Name Description 299 -4 no ipv4 Force IPv4 DNS name resolution 300 - prohibits the option 'ipv6' 301 -6 no ipv6 Force IPv6 DNS name resolution 302 - prohibits the option 'ipv4' 303 -a no authreq Require crypto authentication 304 - prohibits the option 'authnoreq' 305 -A no authnoreq Do not require crypto authentication 306 - prohibits the option 'authreq' 307 -b no bcastsync Allow us to sync to broadcast servers 308 -c Str configfile configuration file name 309 -d no debug-level Increase debug verbosity level 310 - may appear multiple times 311 -D Num set-debug-level Set the debug verbosity level 312 - may appear multiple times 313 -f Str driftfile frequency drift file name 314 -g no panicgate Allow the first adjustment to be Big 315 - may appear multiple times 316 -G no force-step-once Step any initial offset correction. 317 -i --- jaildir built without --enable-clockctl or --enable-linuxcaps or --enable-solarisprivs 318 -I Str interface Listen on an interface name or address 319 - may appear multiple times 320 -k Str keyfile path to symmetric keys 321 -l Str logfile path to the log file 322 -L no novirtualips Do not listen to virtual interfaces 323 -n no nofork Do not fork 324 - prohibits the option 'wait-sync' 325 -N no nice Run at high priority 326 -p Str pidfile path to the PID file 327 -P Num priority Process priority 328 -q no quit Set the time and quit 329 - prohibits these options: 330 saveconfigquit 331 wait-sync 332 -r Str propagationdelay Broadcast/propagation delay 333 Str saveconfigquit Save parsed configuration and quit 334 - prohibits these options: 335 quit 336 wait-sync 337 -s Str statsdir Statistics file location 338 -t Str trustedkey Trusted key number 339 - may appear multiple times 340 -u --- user built without --enable-clockctl or --enable-linuxcaps or --enable-solarisprivs 341 -U Num updateinterval interval in seconds between scans for new or dropped interfaces 342 Str var make ARG an ntp variable (RW) 343 - may appear multiple times 344 Str dvar make ARG an ntp variable (RW|DEF) 345 - may appear multiple times 346 -w Num wait-sync Seconds to wait for first clock sync 347 - prohibits these options: 348 nofork 349 quit 350 saveconfigquit 351 -x no slew Slew up to 600 seconds 352 opt version output version information and exit 353 -? no help display extended usage information and exit 354 -! no more-help extended usage information passed thru pager 355 356Options are specified by doubled hyphens and their name or by a single 357hyphen and the flag character. 358 359 360The following option preset mechanisms are supported: 361 - examining environment variables named NTPD_* 362 363Please send bug reports to: <https://bugs.ntp.org, bugs@ntp.org> 364</pre></div> 365 366<hr> 367<span id="ntpd-ipv4"></span><div class="header"> 368<p> 369Next: <a href="#ntpd-ipv6" accesskey="n" rel="next">ntpd ipv6</a>, Previous: <a href="#ntpd-usage" accesskey="p" rel="prev">ntpd usage</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 370</div> 371<span id="ipv4-option-_0028_002d4_0029"></span><h4 class="subsection">1.1.2 ipv4 option (-4)</h4> 372<span id="index-ntpd_002dipv4"></span> 373 374<p>This is the “force ipv4 dns name resolution” option. 375</p> 376<p>This option has some usage constraints. It: 377</p><ul> 378<li> must not appear in combination with any of the following options: 379ipv6. 380</li></ul> 381 382<p>Force DNS resolution of following host names on the command line 383to the IPv4 namespace. 384</p><hr> 385<span id="ntpd-ipv6"></span><div class="header"> 386<p> 387Next: <a href="#ntpd-authreq" accesskey="n" rel="next">ntpd authreq</a>, Previous: <a href="#ntpd-ipv4" accesskey="p" rel="prev">ntpd ipv4</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 388</div> 389<span id="ipv6-option-_0028_002d6_0029"></span><h4 class="subsection">1.1.3 ipv6 option (-6)</h4> 390<span id="index-ntpd_002dipv6"></span> 391 392<p>This is the “force ipv6 dns name resolution” option. 393</p> 394<p>This option has some usage constraints. It: 395</p><ul> 396<li> must not appear in combination with any of the following options: 397ipv4. 398</li></ul> 399 400<p>Force DNS resolution of following host names on the command line 401to the IPv6 namespace. 402</p><hr> 403<span id="ntpd-authreq"></span><div class="header"> 404<p> 405Next: <a href="#ntpd-authnoreq" accesskey="n" rel="next">ntpd authnoreq</a>, Previous: <a href="#ntpd-ipv6" accesskey="p" rel="prev">ntpd ipv6</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 406</div> 407<span id="authreq-option-_0028_002da_0029"></span><h4 class="subsection">1.1.4 authreq option (-a)</h4> 408<span id="index-ntpd_002dauthreq"></span> 409 410<p>This is the “require crypto authentication” option. 411</p> 412<p>This option has some usage constraints. It: 413</p><ul> 414<li> must not appear in combination with any of the following options: 415authnoreq. 416</li></ul> 417 418<p>Require cryptographic authentication for broadcast client, 419multicast client and symmetric passive associations. 420This is the default. 421</p><hr> 422<span id="ntpd-authnoreq"></span><div class="header"> 423<p> 424Next: <a href="#ntpd-configfile" accesskey="n" rel="next">ntpd configfile</a>, Previous: <a href="#ntpd-authreq" accesskey="p" rel="prev">ntpd authreq</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 425</div> 426<span id="authnoreq-option-_0028_002dA_0029"></span><h4 class="subsection">1.1.5 authnoreq option (-A)</h4> 427<span id="index-ntpd_002dauthnoreq"></span> 428 429<p>This is the “do not require crypto authentication” option. 430</p> 431<p>This option has some usage constraints. It: 432</p><ul> 433<li> must not appear in combination with any of the following options: 434authreq. 435</li></ul> 436 437<p>Do not require cryptographic authentication for broadcast client, 438multicast client and symmetric passive associations. 439This is almost never a good idea. 440</p><hr> 441<span id="ntpd-configfile"></span><div class="header"> 442<p> 443Next: <a href="#ntpd-driftfile" accesskey="n" rel="next">ntpd driftfile</a>, Previous: <a href="#ntpd-authnoreq" accesskey="p" rel="prev">ntpd authnoreq</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 444</div> 445<span id="configfile-option-_0028_002dc_0029"></span><h4 class="subsection">1.1.6 configfile option (-c)</h4> 446<span id="index-ntpd_002dconfigfile"></span> 447 448<p>This is the “configuration file name” option. 449This option takes a string argument. 450The name and path of the configuration file, 451<samp>/etc/ntp.conf</samp> 452by default. 453</p><hr> 454<span id="ntpd-driftfile"></span><div class="header"> 455<p> 456Next: <a href="#ntpd-panicgate" accesskey="n" rel="next">ntpd panicgate</a>, Previous: <a href="#ntpd-configfile" accesskey="p" rel="prev">ntpd configfile</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 457</div> 458<span id="driftfile-option-_0028_002df_0029"></span><h4 class="subsection">1.1.7 driftfile option (-f)</h4> 459<span id="index-ntpd_002ddriftfile"></span> 460 461<p>This is the “frequency drift file name” option. 462This option takes a string argument. 463The name and path of the frequency file, 464<samp>/etc/ntp.drift</samp> 465by default. 466This is the same operation as the 467<code>driftfile</code> <kbd>driftfile</kbd> 468configuration specification in the 469<samp>/etc/ntp.conf</samp> 470file. 471</p><hr> 472<span id="ntpd-panicgate"></span><div class="header"> 473<p> 474Next: <a href="#ntpd-force_002dstep_002donce" accesskey="n" rel="next">ntpd force-step-once</a>, Previous: <a href="#ntpd-driftfile" accesskey="p" rel="prev">ntpd driftfile</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 475</div> 476<span id="panicgate-option-_0028_002dg_0029"></span><h4 class="subsection">1.1.8 panicgate option (-g)</h4> 477<span id="index-ntpd_002dpanicgate"></span> 478 479<p>This is the “allow the first adjustment to be big” option. 480</p> 481<p>This option has some usage constraints. It: 482</p><ul> 483<li> may appear an unlimited number of times. 484</li></ul> 485 486<p>Normally, 487<code>ntpd</code> 488exits 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, 489<code>ntpd</code> 490will exit with a message to the system log. This option can be used with the 491<code>-q</code> 492and 493<code>-x</code> 494options. 495See the 496<code>tinker</code> 497configuration file directive for other options. 498</p><hr> 499<span id="ntpd-force_002dstep_002donce"></span><div class="header"> 500<p> 501Next: <a href="#ntpd-jaildir" accesskey="n" rel="next">ntpd jaildir</a>, Previous: <a href="#ntpd-panicgate" accesskey="p" rel="prev">ntpd panicgate</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 502</div> 503<span id="force_002dstep_002donce-option-_0028_002dG_0029"></span><h4 class="subsection">1.1.9 force-step-once option (-G)</h4> 504<span id="index-ntpd_002dforce_002dstep_002donce"></span> 505 506<p>This is the “step any initial offset correction.” option. 507Normally, 508<code>ntpd</code> 509steps the time if the time offset exceeds the step threshold, 510which is 128 ms by default, and otherwise slews the time. 511This option forces the initial offset correction to be stepped, 512so the highest time accuracy can be achieved quickly. 513However, this may also cause the time to be stepped back 514so this option must not be used if 515applications requiring monotonic time are running. 516See the <code>tinker</code> configuration file directive for other options. 517</p><hr> 518<span id="ntpd-jaildir"></span><div class="header"> 519<p> 520Next: <a href="#ntpd-interface" accesskey="n" rel="next">ntpd interface</a>, Previous: <a href="#ntpd-force_002dstep_002donce" accesskey="p" rel="prev">ntpd force-step-once</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 521</div> 522<span id="jaildir-option-_0028_002di_0029"></span><h4 class="subsection">1.1.10 jaildir option (-i)</h4> 523<span id="index-ntpd_002djaildir"></span> 524 525<p>This is the “jail directory” option. 526This option takes a string argument. 527</p> 528<p>This option has some usage constraints. It: 529</p><ul> 530<li> must be compiled in by defining <code>HAVE_DROPROOT</code> during the compilation. 531</li></ul> 532 533<p>Chroot the server to the directory 534<kbd>jaildir</kbd> 535. 536This option also implies that the server attempts to drop root privileges at startup. 537You may need to also specify a 538<code>-u</code> 539option. 540This option is only available if the OS supports adjusting the clock 541without full root privileges. 542This option is supported under NetBSD (configure with 543<code>--enable-clockctl</code>) or Linux (configure with 544<code>--enable-linuxcaps</code>) or Solaris (configure with <code>--enable-solarisprivs</code>). 545</p><hr> 546<span id="ntpd-interface"></span><div class="header"> 547<p> 548Next: <a href="#ntpd-keyfile" accesskey="n" rel="next">ntpd keyfile</a>, Previous: <a href="#ntpd-jaildir" accesskey="p" rel="prev">ntpd jaildir</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 549</div> 550<span id="interface-option-_0028_002dI_0029"></span><h4 class="subsection">1.1.11 interface option (-I)</h4> 551<span id="index-ntpd_002dinterface"></span> 552 553<p>This is the “listen on an interface name or address” option. 554This option takes a string argument <samp>iface</samp>. 555</p> 556<p>This option has some usage constraints. It: 557</p><ul> 558<li> may appear an unlimited number of times. 559</li></ul> 560 561<p>Open the network address given, or all the addresses associated with the 562given interface name. This option may appear multiple times. This option 563also implies not opening other addresses, except wildcard and localhost. 564This option is deprecated. Please consider using the configuration file 565<code>interface</code> command, which is more versatile. 566</p><hr> 567<span id="ntpd-keyfile"></span><div class="header"> 568<p> 569Next: <a href="#ntpd-logfile" accesskey="n" rel="next">ntpd logfile</a>, Previous: <a href="#ntpd-interface" accesskey="p" rel="prev">ntpd interface</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 570</div> 571<span id="keyfile-option-_0028_002dk_0029"></span><h4 class="subsection">1.1.12 keyfile option (-k)</h4> 572<span id="index-ntpd_002dkeyfile"></span> 573 574<p>This is the “path to symmetric keys” option. 575This option takes a string argument. 576Specify the name and path of the symmetric key file. 577<samp>/etc/ntp.keys</samp> 578is the default. 579This is the same operation as the 580<code>keys</code> <kbd>keyfile</kbd> 581configuration file directive. 582</p><hr> 583<span id="ntpd-logfile"></span><div class="header"> 584<p> 585Next: <a href="#ntpd-novirtualips" accesskey="n" rel="next">ntpd novirtualips</a>, Previous: <a href="#ntpd-keyfile" accesskey="p" rel="prev">ntpd keyfile</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 586</div> 587<span id="logfile-option-_0028_002dl_0029"></span><h4 class="subsection">1.1.13 logfile option (-l)</h4> 588<span id="index-ntpd_002dlogfile"></span> 589 590<p>This is the “path to the log file” option. 591This option takes a string argument. 592Specify the name and path of the log file. 593The default is the system log file. 594This is the same operation as the 595<code>logfile</code> <kbd>logfile</kbd> 596configuration file directive. 597</p><hr> 598<span id="ntpd-novirtualips"></span><div class="header"> 599<p> 600Next: <a href="#ntpd-modifymmtimer" accesskey="n" rel="next">ntpd modifymmtimer</a>, Previous: <a href="#ntpd-logfile" accesskey="p" rel="prev">ntpd logfile</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 601</div> 602<span id="novirtualips-option-_0028_002dL_0029"></span><h4 class="subsection">1.1.14 novirtualips option (-L)</h4> 603<span id="index-ntpd_002dnovirtualips"></span> 604 605<p>This is the “do not listen to virtual interfaces” option. 606Do not listen to virtual interfaces, defined as those with 607names containing a colon. This option is deprecated. Please 608consider using the configuration file <code>interface</code> command, which 609is more versatile. 610</p><hr> 611<span id="ntpd-modifymmtimer"></span><div class="header"> 612<p> 613Next: <a href="#ntpd-nice" accesskey="n" rel="next">ntpd nice</a>, Previous: <a href="#ntpd-novirtualips" accesskey="p" rel="prev">ntpd novirtualips</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 614</div> 615<span id="modifymmtimer-option-_0028_002dM_0029"></span><h4 class="subsection">1.1.15 modifymmtimer option (-M)</h4> 616<span id="index-ntpd_002dmodifymmtimer"></span> 617 618<p>This is the “modify multimedia timer (windows only)” option. 619</p> 620<p>This option has some usage constraints. It: 621</p><ul> 622<li> must be compiled in by defining <code>SYS_WINNT</code> during the compilation. 623</li></ul> 624 625<p>Set the Windows Multimedia Timer to highest resolution. This 626ensures the resolution does not change while ntpd is running, 627avoiding timekeeping glitches associated with changes. 628</p><hr> 629<span id="ntpd-nice"></span><div class="header"> 630<p> 631Next: <a href="#ntpd-pidfile" accesskey="n" rel="next">ntpd pidfile</a>, Previous: <a href="#ntpd-modifymmtimer" accesskey="p" rel="prev">ntpd modifymmtimer</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 632</div> 633<span id="nice-option-_0028_002dN_0029"></span><h4 class="subsection">1.1.16 nice option (-N)</h4> 634<span id="index-ntpd_002dnice"></span> 635 636<p>This is the “run at high priority” option. 637To the extent permitted by the operating system, run 638<code>ntpd</code> 639at the highest priority. 640</p><hr> 641<span id="ntpd-pidfile"></span><div class="header"> 642<p> 643Next: <a href="#ntpd-priority" accesskey="n" rel="next">ntpd priority</a>, Previous: <a href="#ntpd-nice" accesskey="p" rel="prev">ntpd nice</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 644</div> 645<span id="pidfile-option-_0028_002dp_0029"></span><h4 class="subsection">1.1.17 pidfile option (-p)</h4> 646<span id="index-ntpd_002dpidfile"></span> 647 648<p>This is the “path to the pid file” option. 649This option takes a string argument. 650Specify the name and path of the file used to record 651<code>ntpd</code>’s 652process ID. 653This is the same operation as the 654<code>pidfile</code> <kbd>pidfile</kbd> 655configuration file directive. 656</p><hr> 657<span id="ntpd-priority"></span><div class="header"> 658<p> 659Next: <a href="#ntpd-quit" accesskey="n" rel="next">ntpd quit</a>, Previous: <a href="#ntpd-pidfile" accesskey="p" rel="prev">ntpd pidfile</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 660</div> 661<span id="priority-option-_0028_002dP_0029"></span><h4 class="subsection">1.1.18 priority option (-P)</h4> 662<span id="index-ntpd_002dpriority"></span> 663 664<p>This is the “process priority” option. 665This option takes a number argument. 666To the extent permitted by the operating system, run 667<code>ntpd</code> 668at the specified 669<code>sched_setscheduler(SCHED_FIFO)</code> 670priority. 671</p><hr> 672<span id="ntpd-quit"></span><div class="header"> 673<p> 674Next: <a href="#ntpd-propagationdelay" accesskey="n" rel="next">ntpd propagationdelay</a>, Previous: <a href="#ntpd-priority" accesskey="p" rel="prev">ntpd priority</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 675</div> 676<span id="quit-option-_0028_002dq_0029"></span><h4 class="subsection">1.1.19 quit option (-q)</h4> 677<span id="index-ntpd_002dquit"></span> 678 679<p>This is the “set the time and quit” option. 680</p> 681<p>This option has some usage constraints. It: 682</p><ul> 683<li> must not appear in combination with any of the following options: 684saveconfigquit, wait-sync. 685</li></ul> 686 687<p><code>ntpd</code> 688will not daemonize and will exit after the clock is first 689synchronized. This behavior mimics that of the 690<code>ntpdate</code> 691program, which will soon be replaced with a shell script. 692The 693<code>-g</code> 694and 695<code>-x</code> 696options can be used with this option. 697Note: The kernel time discipline is disabled with this option. 698</p><hr> 699<span id="ntpd-propagationdelay"></span><div class="header"> 700<p> 701Next: <a href="#ntpd-saveconfigquit" accesskey="n" rel="next">ntpd saveconfigquit</a>, Previous: <a href="#ntpd-quit" accesskey="p" rel="prev">ntpd quit</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 702</div> 703<span id="propagationdelay-option-_0028_002dr_0029"></span><h4 class="subsection">1.1.20 propagationdelay option (-r)</h4> 704<span id="index-ntpd_002dpropagationdelay"></span> 705 706<p>This is the “broadcast/propagation delay” option. 707This option takes a string argument. 708Specify 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. 709</p><hr> 710<span id="ntpd-saveconfigquit"></span><div class="header"> 711<p> 712Next: <a href="#ntpd-statsdir" accesskey="n" rel="next">ntpd statsdir</a>, Previous: <a href="#ntpd-propagationdelay" accesskey="p" rel="prev">ntpd propagationdelay</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 713</div> 714<span id="saveconfigquit-option"></span><h4 class="subsection">1.1.21 saveconfigquit option</h4> 715<span id="index-ntpd_002dsaveconfigquit"></span> 716 717<p>This is the “save parsed configuration and quit” option. 718This option takes a string argument. 719</p> 720<p>This option has some usage constraints. It: 721</p><ul> 722<li> must be compiled in by defining <code>SAVECONFIG</code> during the compilation. 723</li><li> must not appear in combination with any of the following options: 724quit, wait-sync. 725</li></ul> 726 727<p>Cause <code>ntpd</code> to parse its startup configuration file and save an 728equivalent to the given filename and exit. This option was 729designed for automated testing. 730</p><hr> 731<span id="ntpd-statsdir"></span><div class="header"> 732<p> 733Next: <a href="#ntpd-trustedkey" accesskey="n" rel="next">ntpd trustedkey</a>, Previous: <a href="#ntpd-saveconfigquit" accesskey="p" rel="prev">ntpd saveconfigquit</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 734</div> 735<span id="statsdir-option-_0028_002ds_0029"></span><h4 class="subsection">1.1.22 statsdir option (-s)</h4> 736<span id="index-ntpd_002dstatsdir"></span> 737 738<p>This is the “statistics file location” option. 739This option takes a string argument. 740Specify the directory path for files created by the statistics facility. 741This is the same operation as the 742<code>statsdir</code> <kbd>statsdir</kbd> 743configuration file directive. 744</p><hr> 745<span id="ntpd-trustedkey"></span><div class="header"> 746<p> 747Next: <a href="#ntpd-user" accesskey="n" rel="next">ntpd user</a>, Previous: <a href="#ntpd-statsdir" accesskey="p" rel="prev">ntpd statsdir</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 748</div> 749<span id="trustedkey-option-_0028_002dt_0029"></span><h4 class="subsection">1.1.23 trustedkey option (-t)</h4> 750<span id="index-ntpd_002dtrustedkey"></span> 751 752<p>This is the “trusted key number” option. 753This option takes a string argument <samp>tkey</samp>. 754</p> 755<p>This option has some usage constraints. It: 756</p><ul> 757<li> may appear an unlimited number of times. 758</li></ul> 759 760<p>Add the specified key number to the trusted key list. 761</p><hr> 762<span id="ntpd-user"></span><div class="header"> 763<p> 764Next: <a href="#ntpd-updateinterval" accesskey="n" rel="next">ntpd updateinterval</a>, Previous: <a href="#ntpd-trustedkey" accesskey="p" rel="prev">ntpd trustedkey</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 765</div> 766<span id="user-option-_0028_002du_0029"></span><h4 class="subsection">1.1.24 user option (-u)</h4> 767<span id="index-ntpd_002duser"></span> 768 769<p>This is the “run as userid (or userid:groupid)” option. 770This option takes a string argument. 771</p> 772<p>This option has some usage constraints. It: 773</p><ul> 774<li> must be compiled in by defining <code>HAVE_DROPROOT</code> during the compilation. 775</li></ul> 776 777<p>Specify a user, and optionally a group, to switch to. 778This option is only available if the OS supports adjusting the clock 779without full root privileges. 780This option is supported under NetBSD (configure with 781<code>--enable-clockctl</code>) or Linux (configure with 782<code>--enable-linuxcaps</code>) or Solaris (configure with <code>--enable-solarisprivs</code>). 783</p><hr> 784<span id="ntpd-updateinterval"></span><div class="header"> 785<p> 786Next: <a href="#ntpd-wait_002dsync" accesskey="n" rel="next">ntpd wait-sync</a>, Previous: <a href="#ntpd-user" accesskey="p" rel="prev">ntpd user</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 787</div> 788<span id="updateinterval-option-_0028_002dU_0029"></span><h4 class="subsection">1.1.25 updateinterval option (-U)</h4> 789<span id="index-ntpd_002dupdateinterval"></span> 790 791<p>This is the “interval in seconds between scans for new or dropped interfaces” option. 792This option takes a number argument. 793Give the time in seconds between two scans for new or dropped interfaces. 794For systems with routing socket support the scans will be performed shortly after the interface change 795has been detected by the system. 796Use 0 to disable scanning. 60 seconds is the minimum time between scans. 797</p><hr> 798<span id="ntpd-wait_002dsync"></span><div class="header"> 799<p> 800Next: <a href="#ntpd-slew" accesskey="n" rel="next">ntpd slew</a>, Previous: <a href="#ntpd-updateinterval" accesskey="p" rel="prev">ntpd updateinterval</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 801</div> 802<span id="wait_002dsync-option-_0028_002dw_0029"></span><h4 class="subsection">1.1.26 wait-sync option (-w)</h4> 803<span id="index-ntpd_002dwait_002dsync"></span> 804 805<p>This is the “seconds to wait for first clock sync” option. 806This option takes a number argument. 807</p> 808<p>This option has some usage constraints. It: 809</p><ul> 810<li> must be compiled in by defining <code>HAVE_WORKING_FORK</code> during the compilation. 811</li><li> must not appear in combination with any of the following options: 812nofork, quit, saveconfigquit. 813</li></ul> 814 815<p>If greater than zero, alters <code>ntpd</code>’s behavior when forking to 816daemonize. Instead of exiting with status 0 immediately after 817the fork, the parent waits up to the specified number of 818seconds for the child to first synchronize the clock. The exit 819status is zero (success) if the clock was synchronized, 820otherwise it is <code>ETIMEDOUT</code>. 821This provides the option for a script starting <code>ntpd</code> to easily 822wait for the first set of the clock before proceeding. 823</p><hr> 824<span id="ntpd-slew"></span><div class="header"> 825<p> 826Next: <a href="#ntpd-usepcc" accesskey="n" rel="next">ntpd usepcc</a>, Previous: <a href="#ntpd-wait_002dsync" accesskey="p" rel="prev">ntpd wait-sync</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 827</div> 828<span id="slew-option-_0028_002dx_0029"></span><h4 class="subsection">1.1.27 slew option (-x)</h4> 829<span id="index-ntpd_002dslew"></span> 830 831<p>This is the “slew up to 600 seconds” option. 832Normally, 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. 833This option sets the threshold to 600 s, which is well within the accuracy window to set the clock manually. 834Note: 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. 835Thus, an adjustment as much as 600 s will take almost 14 days to complete. 836This option can be used with the 837<code>-g</code> 838and 839<code>-q</code> 840options. 841See the 842<code>tinker</code> 843configuration file directive for other options. 844Note: The kernel time discipline is disabled with this option. 845</p><hr> 846<span id="ntpd-usepcc"></span><div class="header"> 847<p> 848Next: <a href="#ntpd-pccfreq" accesskey="n" rel="next">ntpd pccfreq</a>, Previous: <a href="#ntpd-slew" accesskey="p" rel="prev">ntpd slew</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 849</div> 850<span id="usepcc-option"></span><h4 class="subsection">1.1.28 usepcc option</h4> 851<span id="index-ntpd_002dusepcc"></span> 852 853<p>This is the “use cpu cycle counter (windows only)” option. 854</p> 855<p>This option has some usage constraints. It: 856</p><ul> 857<li> must be compiled in by defining <code>SYS_WINNT</code> during the compilation. 858</li></ul> 859 860<p>Attempt to substitute the CPU counter for <code>QueryPerformanceCounter</code>. 861The CPU counter and <code>QueryPerformanceCounter</code> are compared, and if 862they have the same frequency, the CPU counter (RDTSC on x86) is 863used directly, saving the overhead of a system call. 864</p><hr> 865<span id="ntpd-pccfreq"></span><div class="header"> 866<p> 867Next: <a href="#ntpd-mdns" accesskey="n" rel="next">ntpd mdns</a>, Previous: <a href="#ntpd-usepcc" accesskey="p" rel="prev">ntpd usepcc</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 868</div> 869<span id="pccfreq-option"></span><h4 class="subsection">1.1.29 pccfreq option</h4> 870<span id="index-ntpd_002dpccfreq"></span> 871 872<p>This is the “force cpu cycle counter use (windows only)” option. 873This option takes a string argument. 874</p> 875<p>This option has some usage constraints. It: 876</p><ul> 877<li> must be compiled in by defining <code>SYS_WINNT</code> during the compilation. 878</li></ul> 879 880<p>Force substitution the CPU counter for <code>QueryPerformanceCounter</code>. 881The CPU counter (RDTSC on x86) is used unconditionally with the 882given frequency (in Hz). 883</p><hr> 884<span id="ntpd-mdns"></span><div class="header"> 885<p> 886Next: <a href="#ntpd-config" accesskey="n" rel="next">ntpd config</a>, Previous: <a href="#ntpd-pccfreq" accesskey="p" rel="prev">ntpd pccfreq</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 887</div> 888<span id="mdns-option-_0028_002dm_0029"></span><h4 class="subsection">1.1.30 mdns option (-m)</h4> 889<span id="index-ntpd_002dmdns"></span> 890 891<p>This is the “register with mdns as a ntp server” option. 892</p> 893<p>This option has some usage constraints. It: 894</p><ul> 895<li> must be compiled in by defining <code>HAVE_DNSREGISTRATION</code> during the compilation. 896</li></ul> 897 898<p>Registers as an NTP server with the local mDNS server which allows 899the server to be discovered via mDNS client lookup. 900</p> 901 902<hr> 903<span id="ntpd-config"></span><div class="header"> 904<p> 905Next: <a href="#ntpd-exit-status" accesskey="n" rel="next">ntpd exit status</a>, Previous: <a href="#ntpd-mdns" accesskey="p" rel="prev">ntpd mdns</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 906</div> 907<span id="presetting_002fconfiguring-ntpd"></span><h4 class="subsection">1.1.31 presetting/configuring ntpd</h4> 908 909<p>Any option that is not marked as <i>not presettable</i> may be preset by 910loading values from environment variables named <code>NTPD</code> and <code>NTPD_<OPTION_NAME></code>. <code><OPTION_NAME></code> must be one of 911the options listed above in upper case and segmented with underscores. 912The <code>NTPD</code> variable will be tokenized and parsed like 913the command line. The remaining variables are tested for existence and their 914values are treated like option arguments. 915</p> 916 917<p>The command line options relating to configuration and/or usage help are: 918</p> 919<span id="version-_0028_002d_0029"></span><h4 class="subsubheading">version (-)</h4> 920 921<p>Print the program version to standard out, optionally with licensing 922information, then exit 0. The optional argument specifies how much licensing 923detail to provide. The default is to print just the version. The licensing information may be selected with an option argument. 924Only the first letter of the argument is examined: 925</p> 926<dl compact="compact"> 927<dt>‘<samp>version</samp>’</dt> 928<dd><p>Only print the version. This is the default. 929</p></dd> 930<dt>‘<samp>copyright</samp>’</dt> 931<dd><p>Name the copyright usage licensing terms. 932</p></dd> 933<dt>‘<samp>verbose</samp>’</dt> 934<dd><p>Print the full copyright usage licensing terms. 935</p></dd> 936</dl> 937 938<hr> 939<span id="ntpd-exit-status"></span><div class="header"> 940<p> 941Next: <a href="#ntpd-Usage" accesskey="n" rel="next">ntpd Usage</a>, Previous: <a href="#ntpd-config" accesskey="p" rel="prev">ntpd config</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 942</div> 943<span id="ntpd-exit-status-1"></span><h4 class="subsection">1.1.32 ntpd exit status</h4> 944 945<p>One of the following exit values will be returned: 946</p><dl compact="compact"> 947<dt>‘<samp>0 (EXIT_SUCCESS)</samp>’</dt> 948<dd><p>Successful program execution. 949</p></dd> 950<dt>‘<samp>1 (EXIT_FAILURE)</samp>’</dt> 951<dd><p>The operation failed or the command syntax was not valid. 952</p></dd> 953</dl> 954<hr> 955<span id="ntpd-Usage"></span><div class="header"> 956<p> 957Next: <a href="#ntpd-Files" accesskey="n" rel="next">ntpd Files</a>, Previous: <a href="#ntpd-exit-status" accesskey="p" rel="prev">ntpd exit status</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 958</div> 959<span id="ntpd-Usage-1"></span><h4 class="subsection">1.1.33 ntpd Usage</h4> 960<hr> 961<span id="ntpd-Files"></span><div class="header"> 962<p> 963Next: <a href="#ntpd-See-Also" accesskey="n" rel="next">ntpd See Also</a>, Previous: <a href="#ntpd-Usage" accesskey="p" rel="prev">ntpd Usage</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 964</div> 965<span id="ntpd-Files-1"></span><h4 class="subsection">1.1.34 ntpd Files</h4> 966<hr> 967<span id="ntpd-See-Also"></span><div class="header"> 968<p> 969Next: <a href="#ntpd-Bugs" accesskey="n" rel="next">ntpd Bugs</a>, Previous: <a href="#ntpd-Files" accesskey="p" rel="prev">ntpd Files</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 970</div> 971<span id="ntpd-See-Also-1"></span><h4 class="subsection">1.1.35 ntpd See Also</h4> 972<hr> 973<span id="ntpd-Bugs"></span><div class="header"> 974<p> 975Next: <a href="#ntpd-Notes" accesskey="n" rel="next">ntpd Notes</a>, Previous: <a href="#ntpd-See-Also" accesskey="p" rel="prev">ntpd See Also</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 976</div> 977<span id="ntpd-Bugs-1"></span><h4 class="subsection">1.1.36 ntpd Bugs</h4> 978<hr> 979<span id="ntpd-Notes"></span><div class="header"> 980<p> 981Previous: <a href="#ntpd-Bugs" accesskey="p" rel="prev">ntpd Bugs</a>, Up: <a href="#ntpd-Invocation" accesskey="u" rel="up">ntpd Invocation</a> </p> 982</div> 983<span id="ntpd-Notes-1"></span><h4 class="subsection">1.1.37 ntpd Notes</h4> 984 985<hr> 986<span id="Usage"></span><div class="header"> 987<p> 988Previous: <a href="#ntpd-Invocation" accesskey="p" rel="prev">ntpd Invocation</a>, Up: <a href="#ntpd-Description" accesskey="u" rel="up">ntpd Description</a> </p> 989</div> 990<span id="Usage-1"></span><h3 class="section">1.2 Usage</h3> 991 992<table> 993<thead><tr><th width="23%">What</th><th width="23%">Default</th><th width="5%">Flag</th><th width="15%">Option</th></tr></thead> 994<tr><td width="23%">configuration file</td><td width="23%"><code>/etc/ntp.conf</code></td><td width="5%"><code>-c</code></td><td width="15%"><code>conffile</code></td></tr> 995<tr><td width="23%">frequency file</td><td width="23%">none</td><td width="5%"><code>-f</code></td><td width="15%"><code>driftfile</code></td></tr> 996<tr><td width="23%">leapseconds file</td><td width="23%">none</td><td width="5%"></td><td width="15%"><code>leapfile</code></td></tr> 997<tr><td width="23%">process ID file</td><td width="23%">none</td><td width="5%"><code>-p</code></td><td width="15%"><code>pidfile</code></td></tr> 998<tr><td width="23%">log file</td><td width="23%">system log</td><td width="5%"><code>-l</code></td><td width="15%"><code>logfile</code></td></tr> 999<tr><td width="23%">include file</td><td width="23%">none</td><td width="5%">none</td><td width="15%"><code>includefile</code></td></tr> 1000<tr><td width="23%">statistics path</td><td width="23%"><code>/var/NTP</code></td><td width="5%"><code>-s</code></td><td width="15%"><code>statsdir</code></td></tr> 1001<tr><td width="23%">keys path</td><td width="23%"><code>/usr/local/etc</code></td><td width="5%"><code>-k</code></td><td width="15%"><code>keysdir</code></td></tr> 1002</table> 1003<hr> 1004 1005 1006 1007</body> 1008</html> 1009