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1 1.1 christos <html lang="en"> 2 1.1 christos <head> 3 1.1 christos <title>ntpd: Network Time Protocol (NTP) Daemon User's Manual</title> 4 1.1 christos <meta http-equiv="Content-Type" content="text/html"> 5 1.1 christos <meta name="description" content="ntpd: Network Time Protocol (NTP) Daemon User's Manual"> 6 1.1.1.6 christos <meta name="generator" content="makeinfo 4.8"> 7 1.1 christos <link title="Top" rel="top" href="#Top"> 8 1.1 christos <link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> 9 1.1 christos <meta http-equiv="Content-Style-Type" content="text/css"> 10 1.1 christos <style type="text/css"><!-- 11 1.1 christos pre.display { font-family:inherit } 12 1.1 christos pre.format { font-family:inherit } 13 1.1 christos pre.smalldisplay { font-family:inherit; font-size:smaller } 14 1.1 christos pre.smallformat { font-family:inherit; font-size:smaller } 15 1.1 christos pre.smallexample { font-size:smaller } 16 1.1 christos pre.smalllisp { font-size:smaller } 17 1.1.1.6 christos span.sc { font-variant:small-caps } 18 1.1.1.6 christos span.roman { font-family:serif; font-weight:normal; } 19 1.1.1.6 christos span.sansserif { font-family:sans-serif; font-weight:normal; } 20 1.1 christos --></style> 21 1.1 christos </head> 22 1.1 christos <body> 23 1.1 christos <h1 class="settitle">ntpd: Network Time Protocol (NTP) Daemon User's Manual</h1> 24 1.1 christos <div class="node"> 25 1.1 christos <p><hr> 26 1.1.1.6 christos <a name="Top"></a> 27 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-Description">ntpd Description</a>, 28 1.1 christos Previous: <a rel="previous" accesskey="p" href="#dir">(dir)</a>, 29 1.1 christos Up: <a rel="up" accesskey="u" href="#dir">(dir)</a> 30 1.1.1.6 christos 31 1.1 christos </div> 32 1.1 christos 33 1.1 christos <h2 class="unnumbered">ntpd: Network Time Protocol (NTP) Daemon User Manual</h2> 34 1.1 christos 35 1.1 christos <p>The <code>ntpd</code> program is an operating system daemon that synchronizes the 36 1.1 christos system clock to remote NTP time servers or local reference clocks. 37 1.1 christos It is a complete implementation of NTP version 4 defined by RFC-5905, but 38 1.1 christos also retains compatible with version 3 defined by RFC-1305 and versions 39 1.1 christos 1 and 2, defined by RFC-1059 and RFC-1119, respectively. 40 1.1 christos The program can operate in any of several modes, including client/server, 41 1.1 christos symmetric and broadcast modes, and with both symmetric-key and public-key 42 1.1 christos cryptography. 43 1.1 christos 44 1.1.1.6 christos <p>This document applies to version 4.2.8p5 of <code>ntpd</code>. 45 1.1 christos 46 1.1 christos <ul class="menu"> 47 1.1 christos <li><a accesskey="1" href="#ntpd-Description">ntpd Description</a>: Description 48 1.1 christos <li><a accesskey="2" href="#ntpd-Invocation">ntpd Invocation</a>: Invoking ntpd 49 1.1 christos <li><a accesskey="3" href="#Usage">Usage</a>: Usage 50 1.1 christos </ul> 51 1.1 christos 52 1.1 christos <div class="node"> 53 1.1 christos <p><hr> 54 1.1 christos <a name="ntpd-Description"></a> 55 1.1.1.6 christos 56 1.1.1.6 christos 57 1.1 christos </div> 58 1.1 christos 59 1.1 christos <!-- node-name, next, previous, up --> 60 1.1 christos <h3 class="section">Description</h3> 61 1.1 christos 62 1.1 christos <p>The <code>ntpd</code> program ordinarily requires 63 1.1 christos a configuration file described at <a href="#ntp_002econf">ntp.conf</a>. 64 1.1 christos This configuration file contains configuration commands described on 65 1.1 christos the pages listed above. 66 1.1 christos However a client can discover remote servers and configure them 67 1.1 christos automatically. 68 1.1 christos This makes it possible to deploy a fleet of workstations without 69 1.1 christos specifying configuration details specific to the local environment. 70 1.1 christos 71 1.1 christos <p>The <code>ntpd</code> program normally operates continuously while adjusting the 72 1.1 christos system time and frequency, but in some cases this might not be 73 1.1 christos practical. 74 1.1 christos With the <code>-q</code> option <code>ntpd</code> operates as in continuous mode, but 75 1.1 christos exits just after setting the clock for the first time. 76 1.1 christos Most applications will probably want to specify the <code>iburst</code> 77 1.1 christos option with the <code>server</code> command. 78 1.1 christos With this option an initial volley of messages is exchanged to 79 1.1 christos groom the data and set the clock in about ten seconds' time. 80 1.1 christos If nothing is heard after a few minutes' time, 81 1.1 christos the daemon times out and exits without setting the clock. 82 1.1 christos 83 1.1 christos <div class="node"> 84 1.1 christos <p><hr> 85 1.1 christos <a name="ntpd-Invocation"></a> 86 1.1.1.6 christos 87 1.1.1.6 christos 88 1.1 christos </div> 89 1.1 christos 90 1.1 christos <h3 class="section">Invoking ntpd</h3> 91 1.1 christos 92 1.1 christos <p><a name="index-ntpd-1"></a><a name="index-NTP-daemon-program-2"></a> 93 1.1 christos 94 1.1 christos <p>The 95 1.1 christos <code>ntpd</code> 96 1.1 christos utility is an operating system daemon which sets 97 1.1 christos and maintains the system time of day in synchronism with Internet 98 1.1 christos standard time servers. 99 1.1 christos It is a complete implementation of the 100 1.1 christos Network Time Protocol (NTP) version 4, as defined by RFC-5905, 101 1.1 christos but also retains compatibility with 102 1.1 christos version 3, as defined by RFC-1305, and versions 1 103 1.1 christos and 2, as defined by RFC-1059 and RFC-1119, respectively. 104 1.1 christos 105 1.1 christos <p>The 106 1.1 christos <code>ntpd</code> 107 1.1 christos utility does most computations in 64-bit floating point 108 1.1 christos arithmetic and does relatively clumsy 64-bit fixed point operations 109 1.1 christos only when necessary to preserve the ultimate precision, about 232 110 1.1 christos picoseconds. 111 1.1 christos While the ultimate precision is not achievable with 112 1.1 christos ordinary workstations and networks of today, it may be required 113 1.1 christos with future gigahertz CPU clocks and gigabit LANs. 114 1.1 christos 115 1.1 christos <p>Ordinarily, 116 1.1 christos <code>ntpd</code> 117 1.1 christos reads the 118 1.1 christos <code>ntp.conf(5)</code> 119 1.1 christos configuration file at startup time in order to determine the 120 1.1 christos synchronization sources and operating modes. 121 1.1 christos It is also possible to 122 1.1 christos specify a working, although limited, configuration entirely on the 123 1.1 christos command line, obviating the need for a configuration file. 124 1.1 christos This may 125 1.1 christos be particularly useful when the local host is to be configured as a 126 1.1 christos broadcast/multicast client, with all peers being determined by 127 1.1 christos listening to broadcasts at run time. 128 1.1 christos 129 1.1 christos <p>If NetInfo support is built into 130 1.1 christos <code>ntpd</code> 131 1.1 christos then 132 1.1 christos <code>ntpd</code> 133 1.1 christos will attempt to read its configuration from the 134 1.1 christos NetInfo if the default 135 1.1 christos <code>ntp.conf(5)</code> 136 1.1 christos file cannot be read and no file is 137 1.1 christos specified by the 138 1.1 christos <code>-c</code> 139 1.1 christos option. 140 1.1 christos 141 1.1 christos <p>Various internal 142 1.1 christos <code>ntpd</code> 143 1.1 christos variables can be displayed and 144 1.1 christos configuration options altered while the 145 1.1 christos <code>ntpd</code> 146 1.1 christos is running 147 1.1 christos using the 148 1.1 christos <code>ntpq(1ntpqmdoc)</code> 149 1.1 christos and 150 1.1 christos <code>ntpdc(1ntpdcmdoc)</code> 151 1.1 christos utility programs. 152 1.1 christos 153 1.1 christos <p>When 154 1.1 christos <code>ntpd</code> 155 1.1 christos starts it looks at the value of 156 1.1 christos <code>umask(2)</code>, 157 1.1 christos and if zero 158 1.1 christos <code>ntpd</code> 159 1.1 christos will set the 160 1.1 christos <code>umask(2)</code> 161 1.1 christos to 022. 162 1.1 christos 163 1.1 christos <p>This section was generated by <strong>AutoGen</strong>, 164 1.1 christos using the <code>agtexi-cmd</code> template and the option descriptions for the <code>ntpd</code> program. 165 1.1 christos This software is released under the NTP license, <http://ntp.org/license>;. 166 1.1 christos 167 1.1 christos <ul class="menu"> 168 1.1.1.6 christos <li><a accesskey="1" href="#ntpd-usage">ntpd usage</a>: ntpd help/usage (<samp><span class="option">--help</span></samp>) 169 1.1 christos <li><a accesskey="2" href="#ntpd-ipv4">ntpd ipv4</a>: ipv4 option (-4) 170 1.1 christos <li><a accesskey="3" href="#ntpd-ipv6">ntpd ipv6</a>: ipv6 option (-6) 171 1.1 christos <li><a accesskey="4" href="#ntpd-authreq">ntpd authreq</a>: authreq option (-a) 172 1.1 christos <li><a accesskey="5" href="#ntpd-authnoreq">ntpd authnoreq</a>: authnoreq option (-A) 173 1.1 christos <li><a accesskey="6" href="#ntpd-configfile">ntpd configfile</a>: configfile option (-c) 174 1.1 christos <li><a accesskey="7" href="#ntpd-driftfile">ntpd driftfile</a>: driftfile option (-f) 175 1.1 christos <li><a accesskey="8" href="#ntpd-panicgate">ntpd panicgate</a>: panicgate option (-g) 176 1.1.1.3 christos <li><a accesskey="9" href="#ntpd-force_002dstep_002donce">ntpd force-step-once</a>: force-step-once option (-G) 177 1.1.1.3 christos <li><a href="#ntpd-jaildir">ntpd jaildir</a>: jaildir option (-i) 178 1.1 christos <li><a href="#ntpd-interface">ntpd interface</a>: interface option (-I) 179 1.1 christos <li><a href="#ntpd-keyfile">ntpd keyfile</a>: keyfile option (-k) 180 1.1 christos <li><a href="#ntpd-logfile">ntpd logfile</a>: logfile option (-l) 181 1.1 christos <li><a href="#ntpd-novirtualips">ntpd novirtualips</a>: novirtualips option (-L) 182 1.1 christos <li><a href="#ntpd-modifymmtimer">ntpd modifymmtimer</a>: modifymmtimer option (-M) 183 1.1 christos <li><a href="#ntpd-nice">ntpd nice</a>: nice option (-N) 184 1.1 christos <li><a href="#ntpd-pidfile">ntpd pidfile</a>: pidfile option (-p) 185 1.1 christos <li><a href="#ntpd-priority">ntpd priority</a>: priority option (-P) 186 1.1 christos <li><a href="#ntpd-quit">ntpd quit</a>: quit option (-q) 187 1.1 christos <li><a href="#ntpd-propagationdelay">ntpd propagationdelay</a>: propagationdelay option (-r) 188 1.1 christos <li><a href="#ntpd-saveconfigquit">ntpd saveconfigquit</a>: saveconfigquit option 189 1.1 christos <li><a href="#ntpd-statsdir">ntpd statsdir</a>: statsdir option (-s) 190 1.1 christos <li><a href="#ntpd-trustedkey">ntpd trustedkey</a>: trustedkey option (-t) 191 1.1 christos <li><a href="#ntpd-user">ntpd user</a>: user option (-u) 192 1.1 christos <li><a href="#ntpd-updateinterval">ntpd updateinterval</a>: updateinterval option (-U) 193 1.1 christos <li><a href="#ntpd-wait_002dsync">ntpd wait-sync</a>: wait-sync option (-w) 194 1.1 christos <li><a href="#ntpd-slew">ntpd slew</a>: slew option (-x) 195 1.1 christos <li><a href="#ntpd-usepcc">ntpd usepcc</a>: usepcc option 196 1.1 christos <li><a href="#ntpd-pccfreq">ntpd pccfreq</a>: pccfreq option 197 1.1 christos <li><a href="#ntpd-mdns">ntpd mdns</a>: mdns option (-m) 198 1.1 christos <li><a href="#ntpd-config">ntpd config</a>: presetting/configuring ntpd 199 1.1 christos <li><a href="#ntpd-exit-status">ntpd exit status</a>: exit status 200 1.1 christos <li><a href="#ntpd-Usage">ntpd Usage</a>: Usage 201 1.1 christos <li><a href="#ntpd-Files">ntpd Files</a>: Files 202 1.1 christos <li><a href="#ntpd-See-Also">ntpd See Also</a>: See Also 203 1.1 christos <li><a href="#ntpd-Bugs">ntpd Bugs</a>: Bugs 204 1.1 christos <li><a href="#ntpd-Notes">ntpd Notes</a>: Notes 205 1.1 christos </ul> 206 1.1 christos 207 1.1 christos <div class="node"> 208 1.1 christos <p><hr> 209 1.1.1.6 christos <a name="ntpd-usage"></a> 210 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-ipv4">ntpd ipv4</a>, 211 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 212 1.1.1.6 christos 213 1.1 christos </div> 214 1.1 christos 215 1.1.1.6 christos <h4 class="subsection">ntpd help/usage (<samp><span class="option">--help</span></samp>)</h4> 216 1.1 christos 217 1.1 christos <p><a name="index-ntpd-help-3"></a> 218 1.1 christos This is the automatically generated usage text for ntpd. 219 1.1 christos 220 1.1 christos <p>The text printed is the same whether selected with the <code>help</code> option 221 1.1.1.6 christos (<samp><span class="option">--help</span></samp>) or the <code>more-help</code> option (<samp><span class="option">--more-help</span></samp>). <code>more-help</code> will print 222 1.1 christos the usage text by passing it through a pager program. 223 1.1 christos <code>more-help</code> is disabled on platforms without a working 224 1.1 christos <code>fork(2)</code> function. The <code>PAGER</code> environment variable is 225 1.1.1.6 christos used to select the program, defaulting to <samp><span class="file">more</span></samp>. Both will exit 226 1.1 christos with a status code of 0. 227 1.1 christos 228 1.1.1.6 christos <pre class="example">ntpd - NTP daemon program - Ver. 4.2.8p4 229 1.1 christos Usage: ntpd [ -<flag> [<val>] | --<name>[{=| }<val>] ]... \ 230 1.1 christos [ <server1> ... <serverN> ] 231 1.1 christos Flg Arg Option-Name Description 232 1.1 christos -4 no ipv4 Force IPv4 DNS name resolution 233 1.1 christos - prohibits the option 'ipv6' 234 1.1 christos -6 no ipv6 Force IPv6 DNS name resolution 235 1.1 christos - prohibits the option 'ipv4' 236 1.1 christos -a no authreq Require crypto authentication 237 1.1 christos - prohibits the option 'authnoreq' 238 1.1 christos -A no authnoreq Do not require crypto authentication 239 1.1 christos - prohibits the option 'authreq' 240 1.1 christos -b no bcastsync Allow us to sync to broadcast servers 241 1.1 christos -c Str configfile configuration file name 242 1.1 christos -d no debug-level Increase debug verbosity level 243 1.1 christos - may appear multiple times 244 1.1 christos -D Num set-debug-level Set the debug verbosity level 245 1.1 christos - may appear multiple times 246 1.1 christos -f Str driftfile frequency drift file name 247 1.1 christos -g no panicgate Allow the first adjustment to be Big 248 1.1 christos - may appear multiple times 249 1.1.1.3 christos -G no force-step-once Step any initial offset correction. 250 1.1 christos -i Str jaildir Jail directory 251 1.1 christos -I Str interface Listen on an interface name or address 252 1.1 christos - may appear multiple times 253 1.1 christos -k Str keyfile path to symmetric keys 254 1.1 christos -l Str logfile path to the log file 255 1.1 christos -L no novirtualips Do not listen to virtual interfaces 256 1.1 christos -n no nofork Do not fork 257 1.1 christos - prohibits the option 'wait-sync' 258 1.1 christos -N no nice Run at high priority 259 1.1 christos -p Str pidfile path to the PID file 260 1.1 christos -P Num priority Process priority 261 1.1 christos -q no quit Set the time and quit 262 1.1 christos - prohibits these options: 263 1.1 christos saveconfigquit 264 1.1 christos wait-sync 265 1.1 christos -r Str propagationdelay Broadcast/propagation delay 266 1.1 christos Str saveconfigquit Save parsed configuration and quit 267 1.1 christos - prohibits these options: 268 1.1 christos quit 269 1.1 christos wait-sync 270 1.1 christos -s Str statsdir Statistics file location 271 1.1 christos -t Str trustedkey Trusted key number 272 1.1 christos - may appear multiple times 273 1.1 christos -u Str user Run as userid (or userid:groupid) 274 1.1 christos -U Num updateinterval interval in seconds between scans for new or dropped interfaces 275 1.1 christos Str var make ARG an ntp variable (RW) 276 1.1 christos - may appear multiple times 277 1.1 christos Str dvar make ARG an ntp variable (RW|DEF) 278 1.1 christos - may appear multiple times 279 1.1 christos -w Num wait-sync Seconds to wait for first clock sync 280 1.1 christos - prohibits these options: 281 1.1 christos nofork 282 1.1 christos quit 283 1.1 christos saveconfigquit 284 1.1 christos -x no slew Slew up to 600 seconds 285 1.1 christos opt version output version information and exit 286 1.1 christos -? no help display extended usage information and exit 287 1.1 christos -! no more-help extended usage information passed thru pager 288 1.1 christos 289 1.1 christos Options are specified by doubled hyphens and their name or by a single 290 1.1 christos hyphen and the flag character. 291 1.1 christos 292 1.1 christos 293 1.1 christos The following option preset mechanisms are supported: 294 1.1 christos - examining environment variables named NTPD_* 295 1.1 christos 296 1.1 christos Please send bug reports to: <http://bugs.ntp.org, bugs (a] ntp.org> 297 1.1 christos </pre> 298 1.1 christos <div class="node"> 299 1.1 christos <p><hr> 300 1.1.1.6 christos <a name="ntpd-ipv4"></a> 301 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-ipv6">ntpd ipv6</a>, 302 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-usage">ntpd usage</a>, 303 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 304 1.1.1.6 christos 305 1.1 christos </div> 306 1.1 christos 307 1.1 christos <h4 class="subsection">ipv4 option (-4)</h4> 308 1.1 christos 309 1.1 christos <p><a name="index-ntpd_002dipv4-4"></a> 310 1.1 christos This is the “force ipv4 dns name resolution” option. 311 1.1 christos 312 1.1 christos <p class="noindent">This option has some usage constraints. It: 313 1.1 christos <ul> 314 1.1 christos <li>must not appear in combination with any of the following options: 315 1.1 christos ipv6. 316 1.1 christos </ul> 317 1.1 christos 318 1.1 christos <p>Force DNS resolution of following host names on the command line 319 1.1 christos to the IPv4 namespace. 320 1.1 christos <div class="node"> 321 1.1 christos <p><hr> 322 1.1.1.6 christos <a name="ntpd-ipv6"></a> 323 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-authreq">ntpd authreq</a>, 324 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-ipv4">ntpd ipv4</a>, 325 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 326 1.1.1.6 christos 327 1.1 christos </div> 328 1.1 christos 329 1.1 christos <h4 class="subsection">ipv6 option (-6)</h4> 330 1.1 christos 331 1.1 christos <p><a name="index-ntpd_002dipv6-5"></a> 332 1.1 christos This is the “force ipv6 dns name resolution” option. 333 1.1 christos 334 1.1 christos <p class="noindent">This option has some usage constraints. It: 335 1.1 christos <ul> 336 1.1 christos <li>must not appear in combination with any of the following options: 337 1.1 christos ipv4. 338 1.1 christos </ul> 339 1.1 christos 340 1.1 christos <p>Force DNS resolution of following host names on the command line 341 1.1 christos to the IPv6 namespace. 342 1.1 christos <div class="node"> 343 1.1 christos <p><hr> 344 1.1.1.6 christos <a name="ntpd-authreq"></a> 345 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-authnoreq">ntpd authnoreq</a>, 346 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-ipv6">ntpd ipv6</a>, 347 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 348 1.1.1.6 christos 349 1.1 christos </div> 350 1.1 christos 351 1.1 christos <h4 class="subsection">authreq option (-a)</h4> 352 1.1 christos 353 1.1 christos <p><a name="index-ntpd_002dauthreq-6"></a> 354 1.1 christos This is the “require crypto authentication” option. 355 1.1 christos 356 1.1 christos <p class="noindent">This option has some usage constraints. It: 357 1.1 christos <ul> 358 1.1 christos <li>must not appear in combination with any of the following options: 359 1.1 christos authnoreq. 360 1.1 christos </ul> 361 1.1 christos 362 1.1 christos <p>Require cryptographic authentication for broadcast client, 363 1.1 christos multicast client and symmetric passive associations. 364 1.1 christos This is the default. 365 1.1 christos <div class="node"> 366 1.1 christos <p><hr> 367 1.1.1.6 christos <a name="ntpd-authnoreq"></a> 368 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-configfile">ntpd configfile</a>, 369 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-authreq">ntpd authreq</a>, 370 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 371 1.1.1.6 christos 372 1.1 christos </div> 373 1.1 christos 374 1.1 christos <h4 class="subsection">authnoreq option (-A)</h4> 375 1.1 christos 376 1.1 christos <p><a name="index-ntpd_002dauthnoreq-7"></a> 377 1.1 christos This is the “do not require crypto authentication” option. 378 1.1 christos 379 1.1 christos <p class="noindent">This option has some usage constraints. It: 380 1.1 christos <ul> 381 1.1 christos <li>must not appear in combination with any of the following options: 382 1.1 christos authreq. 383 1.1 christos </ul> 384 1.1 christos 385 1.1 christos <p>Do not require cryptographic authentication for broadcast client, 386 1.1 christos multicast client and symmetric passive associations. 387 1.1 christos This is almost never a good idea. 388 1.1 christos <div class="node"> 389 1.1 christos <p><hr> 390 1.1.1.6 christos <a name="ntpd-configfile"></a> 391 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-driftfile">ntpd driftfile</a>, 392 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-authnoreq">ntpd authnoreq</a>, 393 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 394 1.1.1.6 christos 395 1.1 christos </div> 396 1.1 christos 397 1.1 christos <h4 class="subsection">configfile option (-c)</h4> 398 1.1 christos 399 1.1 christos <p><a name="index-ntpd_002dconfigfile-8"></a> 400 1.1 christos This is the “configuration file name” option. 401 1.1 christos This option takes a string argument. 402 1.1 christos The name and path of the configuration file, 403 1.1.1.6 christos <samp><span class="file">/etc/ntp.conf</span></samp> 404 1.1 christos by default. 405 1.1 christos <div class="node"> 406 1.1 christos <p><hr> 407 1.1.1.6 christos <a name="ntpd-driftfile"></a> 408 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-panicgate">ntpd panicgate</a>, 409 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-configfile">ntpd configfile</a>, 410 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 411 1.1.1.6 christos 412 1.1 christos </div> 413 1.1 christos 414 1.1 christos <h4 class="subsection">driftfile option (-f)</h4> 415 1.1 christos 416 1.1 christos <p><a name="index-ntpd_002ddriftfile-9"></a> 417 1.1 christos This is the “frequency drift file name” option. 418 1.1 christos This option takes a string argument. 419 1.1 christos The name and path of the frequency file, 420 1.1.1.6 christos <samp><span class="file">/etc/ntp.drift</span></samp> 421 1.1 christos by default. 422 1.1 christos This is the same operation as the 423 1.1 christos <code>driftfile</code> <kbd>driftfile</kbd> 424 1.1 christos configuration specification in the 425 1.1.1.6 christos <samp><span class="file">/etc/ntp.conf</span></samp> 426 1.1 christos file. 427 1.1 christos <div class="node"> 428 1.1 christos <p><hr> 429 1.1.1.6 christos <a name="ntpd-panicgate"></a> 430 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-force_002dstep_002donce">ntpd force-step-once</a>, 431 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-driftfile">ntpd driftfile</a>, 432 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 433 1.1.1.6 christos 434 1.1 christos </div> 435 1.1 christos 436 1.1 christos <h4 class="subsection">panicgate option (-g)</h4> 437 1.1 christos 438 1.1 christos <p><a name="index-ntpd_002dpanicgate-10"></a> 439 1.1 christos This is the “allow the first adjustment to be big” option. 440 1.1 christos 441 1.1 christos <p class="noindent">This option has some usage constraints. It: 442 1.1 christos <ul> 443 1.1 christos <li>may appear an unlimited number of times. 444 1.1 christos </ul> 445 1.1 christos 446 1.1 christos <p>Normally, 447 1.1 christos <code>ntpd</code> 448 1.1 christos exits 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, 449 1.1 christos <code>ntpd</code> 450 1.1 christos will exit with a message to the system log. This option can be used with the 451 1.1 christos <code>-q</code> 452 1.1 christos and 453 1.1 christos <code>-x</code> 454 1.1 christos options. 455 1.1 christos See the 456 1.1 christos <code>tinker</code> 457 1.1 christos configuration file directive for other options. 458 1.1 christos <div class="node"> 459 1.1 christos <p><hr> 460 1.1.1.6 christos <a name="ntpd-force-step-once"></a> 461 1.1.1.6 christos <a name="ntpd-force_002dstep_002donce"></a> 462 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-jaildir">ntpd jaildir</a>, 463 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-panicgate">ntpd panicgate</a>, 464 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 465 1.1.1.6 christos 466 1.1 christos </div> 467 1.1 christos 468 1.1.1.3 christos <h4 class="subsection">force-step-once option (-G)</h4> 469 1.1.1.3 christos 470 1.1.1.3 christos <p><a name="index-ntpd_002dforce_002dstep_002donce-11"></a> 471 1.1.1.3 christos This is the “step any initial offset correction.” option. 472 1.1.1.3 christos Normally, 473 1.1.1.3 christos <code>ntpd</code> 474 1.1.1.3 christos steps the time if the time offset exceeds the step threshold, 475 1.1.1.3 christos which is 128 ms by default, and otherwise slews the time. 476 1.1.1.3 christos This option forces the initial offset correction to be stepped, 477 1.1.1.3 christos so the highest time accuracy can be achieved quickly. 478 1.1.1.3 christos However, this may also cause the time to be stepped back 479 1.1.1.3 christos so this option must not be used if 480 1.1.1.3 christos applications requiring monotonic time are running. 481 1.1.1.3 christos See the <code>tinker</code> configuration file directive for other options. 482 1.1.1.3 christos <div class="node"> 483 1.1.1.3 christos <p><hr> 484 1.1.1.6 christos <a name="ntpd-jaildir"></a> 485 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-interface">ntpd interface</a>, 486 1.1.1.3 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-force_002dstep_002donce">ntpd force-step-once</a>, 487 1.1.1.3 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 488 1.1.1.6 christos 489 1.1.1.3 christos </div> 490 1.1.1.3 christos 491 1.1 christos <h4 class="subsection">jaildir option (-i)</h4> 492 1.1 christos 493 1.1.1.3 christos <p><a name="index-ntpd_002djaildir-12"></a> 494 1.1 christos This is the “jail directory” option. 495 1.1 christos This option takes a string argument. 496 1.1 christos 497 1.1 christos <p class="noindent">This option has some usage constraints. It: 498 1.1 christos <ul> 499 1.1 christos <li>must be compiled in by defining <code>HAVE_DROPROOT</code> during the compilation. 500 1.1 christos </ul> 501 1.1 christos 502 1.1 christos <p>Chroot the server to the directory 503 1.1 christos <kbd>jaildir</kbd> 504 1.1 christos . 505 1.1 christos This option also implies that the server attempts to drop root privileges at startup. 506 1.1 christos You may need to also specify a 507 1.1 christos <code>-u</code> 508 1.1 christos option. 509 1.1 christos This option is only available if the OS supports adjusting the clock 510 1.1 christos without full root privileges. 511 1.1 christos This option is supported under NetBSD (configure with 512 1.1 christos <code>--enable-clockctl</code>) or Linux (configure with 513 1.1 christos <code>--enable-linuxcaps</code>) or Solaris (configure with <code>--enable-solarisprivs</code>). 514 1.1 christos <div class="node"> 515 1.1 christos <p><hr> 516 1.1.1.6 christos <a name="ntpd-interface"></a> 517 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-keyfile">ntpd keyfile</a>, 518 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-jaildir">ntpd jaildir</a>, 519 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 520 1.1.1.6 christos 521 1.1 christos </div> 522 1.1 christos 523 1.1 christos <h4 class="subsection">interface option (-I)</h4> 524 1.1 christos 525 1.1.1.3 christos <p><a name="index-ntpd_002dinterface-13"></a> 526 1.1 christos This is the “listen on an interface name or address” option. 527 1.1.1.6 christos This option takes a string argument <samp><span class="file">iface</span></samp>. 528 1.1 christos 529 1.1 christos <p class="noindent">This option has some usage constraints. It: 530 1.1 christos <ul> 531 1.1 christos <li>may appear an unlimited number of times. 532 1.1 christos </ul> 533 1.1 christos 534 1.1 christos <p>Open the network address given, or all the addresses associated with the 535 1.1 christos given interface name. This option may appear multiple times. This option 536 1.1 christos also implies not opening other addresses, except wildcard and localhost. 537 1.1 christos This option is deprecated. Please consider using the configuration file 538 1.1 christos <code>interface</code> command, which is more versatile. 539 1.1 christos <div class="node"> 540 1.1 christos <p><hr> 541 1.1.1.6 christos <a name="ntpd-keyfile"></a> 542 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-logfile">ntpd logfile</a>, 543 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-interface">ntpd interface</a>, 544 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 545 1.1.1.6 christos 546 1.1 christos </div> 547 1.1 christos 548 1.1 christos <h4 class="subsection">keyfile option (-k)</h4> 549 1.1 christos 550 1.1.1.3 christos <p><a name="index-ntpd_002dkeyfile-14"></a> 551 1.1 christos This is the “path to symmetric keys” option. 552 1.1 christos This option takes a string argument. 553 1.1 christos Specify the name and path of the symmetric key file. 554 1.1.1.6 christos <samp><span class="file">/etc/ntp.keys</span></samp> 555 1.1 christos is the default. 556 1.1 christos This is the same operation as the 557 1.1 christos <code>keys</code> <kbd>keyfile</kbd> 558 1.1 christos configuration file directive. 559 1.1 christos <div class="node"> 560 1.1 christos <p><hr> 561 1.1.1.6 christos <a name="ntpd-logfile"></a> 562 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-novirtualips">ntpd novirtualips</a>, 563 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-keyfile">ntpd keyfile</a>, 564 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 565 1.1.1.6 christos 566 1.1 christos </div> 567 1.1 christos 568 1.1 christos <h4 class="subsection">logfile option (-l)</h4> 569 1.1 christos 570 1.1.1.3 christos <p><a name="index-ntpd_002dlogfile-15"></a> 571 1.1 christos This is the “path to the log file” option. 572 1.1 christos This option takes a string argument. 573 1.1 christos Specify the name and path of the log file. 574 1.1 christos The default is the system log file. 575 1.1 christos This is the same operation as the 576 1.1 christos <code>logfile</code> <kbd>logfile</kbd> 577 1.1 christos configuration file directive. 578 1.1 christos <div class="node"> 579 1.1 christos <p><hr> 580 1.1.1.6 christos <a name="ntpd-novirtualips"></a> 581 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-modifymmtimer">ntpd modifymmtimer</a>, 582 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-logfile">ntpd logfile</a>, 583 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 584 1.1.1.6 christos 585 1.1 christos </div> 586 1.1 christos 587 1.1 christos <h4 class="subsection">novirtualips option (-L)</h4> 588 1.1 christos 589 1.1.1.3 christos <p><a name="index-ntpd_002dnovirtualips-16"></a> 590 1.1 christos This is the “do not listen to virtual interfaces” option. 591 1.1 christos Do not listen to virtual interfaces, defined as those with 592 1.1 christos names containing a colon. This option is deprecated. Please 593 1.1 christos consider using the configuration file <code>interface</code> command, which 594 1.1 christos is more versatile. 595 1.1 christos <div class="node"> 596 1.1 christos <p><hr> 597 1.1.1.6 christos <a name="ntpd-modifymmtimer"></a> 598 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-nice">ntpd nice</a>, 599 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-novirtualips">ntpd novirtualips</a>, 600 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 601 1.1.1.6 christos 602 1.1 christos </div> 603 1.1 christos 604 1.1 christos <h4 class="subsection">modifymmtimer option (-M)</h4> 605 1.1 christos 606 1.1.1.3 christos <p><a name="index-ntpd_002dmodifymmtimer-17"></a> 607 1.1 christos This is the “modify multimedia timer (windows only)” option. 608 1.1 christos 609 1.1 christos <p class="noindent">This option has some usage constraints. It: 610 1.1 christos <ul> 611 1.1 christos <li>must be compiled in by defining <code>SYS_WINNT</code> during the compilation. 612 1.1 christos </ul> 613 1.1 christos 614 1.1 christos <p>Set the Windows Multimedia Timer to highest resolution. This 615 1.1 christos ensures the resolution does not change while ntpd is running, 616 1.1 christos avoiding timekeeping glitches associated with changes. 617 1.1 christos <div class="node"> 618 1.1 christos <p><hr> 619 1.1.1.6 christos <a name="ntpd-nice"></a> 620 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-pidfile">ntpd pidfile</a>, 621 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-modifymmtimer">ntpd modifymmtimer</a>, 622 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 623 1.1.1.6 christos 624 1.1 christos </div> 625 1.1 christos 626 1.1 christos <h4 class="subsection">nice option (-N)</h4> 627 1.1 christos 628 1.1.1.3 christos <p><a name="index-ntpd_002dnice-18"></a> 629 1.1 christos This is the “run at high priority” option. 630 1.1 christos To the extent permitted by the operating system, run 631 1.1 christos <code>ntpd</code> 632 1.1 christos at the highest priority. 633 1.1 christos <div class="node"> 634 1.1 christos <p><hr> 635 1.1.1.6 christos <a name="ntpd-pidfile"></a> 636 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-priority">ntpd priority</a>, 637 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-nice">ntpd nice</a>, 638 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 639 1.1.1.6 christos 640 1.1 christos </div> 641 1.1 christos 642 1.1 christos <h4 class="subsection">pidfile option (-p)</h4> 643 1.1 christos 644 1.1.1.3 christos <p><a name="index-ntpd_002dpidfile-19"></a> 645 1.1 christos This is the “path to the pid file” option. 646 1.1 christos This option takes a string argument. 647 1.1 christos Specify the name and path of the file used to record 648 1.1 christos <code>ntpd</code>'s 649 1.1 christos process ID. 650 1.1 christos This is the same operation as the 651 1.1 christos <code>pidfile</code> <kbd>pidfile</kbd> 652 1.1 christos configuration file directive. 653 1.1 christos <div class="node"> 654 1.1 christos <p><hr> 655 1.1.1.6 christos <a name="ntpd-priority"></a> 656 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-quit">ntpd quit</a>, 657 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-pidfile">ntpd pidfile</a>, 658 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 659 1.1.1.6 christos 660 1.1 christos </div> 661 1.1 christos 662 1.1 christos <h4 class="subsection">priority option (-P)</h4> 663 1.1 christos 664 1.1.1.3 christos <p><a name="index-ntpd_002dpriority-20"></a> 665 1.1 christos This is the “process priority” option. 666 1.1 christos This option takes a number argument. 667 1.1 christos To the extent permitted by the operating system, run 668 1.1 christos <code>ntpd</code> 669 1.1 christos at the specified 670 1.1 christos <code>sched_setscheduler(SCHED_FIFO)</code> 671 1.1 christos priority. 672 1.1 christos <div class="node"> 673 1.1 christos <p><hr> 674 1.1.1.6 christos <a name="ntpd-quit"></a> 675 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-propagationdelay">ntpd propagationdelay</a>, 676 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-priority">ntpd priority</a>, 677 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 678 1.1.1.6 christos 679 1.1 christos </div> 680 1.1 christos 681 1.1 christos <h4 class="subsection">quit option (-q)</h4> 682 1.1 christos 683 1.1.1.3 christos <p><a name="index-ntpd_002dquit-21"></a> 684 1.1 christos This is the “set the time and quit” option. 685 1.1 christos 686 1.1 christos <p class="noindent">This option has some usage constraints. It: 687 1.1 christos <ul> 688 1.1 christos <li>must not appear in combination with any of the following options: 689 1.1 christos saveconfigquit, wait-sync. 690 1.1 christos </ul> 691 1.1 christos 692 1.1 christos <p><code>ntpd</code> 693 1.1 christos will not daemonize and will exit after the clock is first 694 1.1 christos synchronized. This behavior mimics that of the 695 1.1 christos <code>ntpdate</code> 696 1.1 christos program, which will soon be replaced with a shell script. 697 1.1 christos The 698 1.1 christos <code>-g</code> 699 1.1 christos and 700 1.1 christos <code>-x</code> 701 1.1 christos options can be used with this option. 702 1.1 christos Note: The kernel time discipline is disabled with this option. 703 1.1 christos <div class="node"> 704 1.1 christos <p><hr> 705 1.1.1.6 christos <a name="ntpd-propagationdelay"></a> 706 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-saveconfigquit">ntpd saveconfigquit</a>, 707 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-quit">ntpd quit</a>, 708 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 709 1.1.1.6 christos 710 1.1 christos </div> 711 1.1 christos 712 1.1 christos <h4 class="subsection">propagationdelay option (-r)</h4> 713 1.1 christos 714 1.1.1.3 christos <p><a name="index-ntpd_002dpropagationdelay-22"></a> 715 1.1 christos This is the “broadcast/propagation delay” option. 716 1.1 christos This option takes a string argument. 717 1.1 christos Specify 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. 718 1.1 christos <div class="node"> 719 1.1 christos <p><hr> 720 1.1.1.6 christos <a name="ntpd-saveconfigquit"></a> 721 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-statsdir">ntpd statsdir</a>, 722 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-propagationdelay">ntpd propagationdelay</a>, 723 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 724 1.1.1.6 christos 725 1.1 christos </div> 726 1.1 christos 727 1.1 christos <h4 class="subsection">saveconfigquit option</h4> 728 1.1 christos 729 1.1.1.3 christos <p><a name="index-ntpd_002dsaveconfigquit-23"></a> 730 1.1 christos This is the “save parsed configuration and quit” option. 731 1.1 christos This option takes a string argument. 732 1.1 christos 733 1.1 christos <p class="noindent">This option has some usage constraints. It: 734 1.1 christos <ul> 735 1.1 christos <li>must be compiled in by defining <code>SAVECONFIG</code> during the compilation. 736 1.1 christos <li>must not appear in combination with any of the following options: 737 1.1 christos quit, wait-sync. 738 1.1 christos </ul> 739 1.1 christos 740 1.1 christos <p>Cause <code>ntpd</code> to parse its startup configuration file and save an 741 1.1 christos equivalent to the given filename and exit. This option was 742 1.1 christos designed for automated testing. 743 1.1 christos <div class="node"> 744 1.1 christos <p><hr> 745 1.1.1.6 christos <a name="ntpd-statsdir"></a> 746 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-trustedkey">ntpd trustedkey</a>, 747 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-saveconfigquit">ntpd saveconfigquit</a>, 748 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 749 1.1.1.6 christos 750 1.1 christos </div> 751 1.1 christos 752 1.1 christos <h4 class="subsection">statsdir option (-s)</h4> 753 1.1 christos 754 1.1.1.3 christos <p><a name="index-ntpd_002dstatsdir-24"></a> 755 1.1 christos This is the “statistics file location” option. 756 1.1 christos This option takes a string argument. 757 1.1 christos Specify the directory path for files created by the statistics facility. 758 1.1 christos This is the same operation as the 759 1.1 christos <code>statsdir</code> <kbd>statsdir</kbd> 760 1.1 christos configuration file directive. 761 1.1 christos <div class="node"> 762 1.1 christos <p><hr> 763 1.1.1.6 christos <a name="ntpd-trustedkey"></a> 764 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-user">ntpd user</a>, 765 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-statsdir">ntpd statsdir</a>, 766 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 767 1.1.1.6 christos 768 1.1 christos </div> 769 1.1 christos 770 1.1 christos <h4 class="subsection">trustedkey option (-t)</h4> 771 1.1 christos 772 1.1.1.3 christos <p><a name="index-ntpd_002dtrustedkey-25"></a> 773 1.1 christos This is the “trusted key number” option. 774 1.1.1.6 christos This option takes a string argument <samp><span class="file">tkey</span></samp>. 775 1.1 christos 776 1.1 christos <p class="noindent">This option has some usage constraints. It: 777 1.1 christos <ul> 778 1.1 christos <li>may appear an unlimited number of times. 779 1.1 christos </ul> 780 1.1 christos 781 1.1 christos <p>Add the specified key number to the trusted key list. 782 1.1 christos <div class="node"> 783 1.1 christos <p><hr> 784 1.1.1.6 christos <a name="ntpd-user"></a> 785 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-updateinterval">ntpd updateinterval</a>, 786 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-trustedkey">ntpd trustedkey</a>, 787 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 788 1.1.1.6 christos 789 1.1 christos </div> 790 1.1 christos 791 1.1 christos <h4 class="subsection">user option (-u)</h4> 792 1.1 christos 793 1.1.1.3 christos <p><a name="index-ntpd_002duser-26"></a> 794 1.1 christos This is the “run as userid (or userid:groupid)” option. 795 1.1 christos This option takes a string argument. 796 1.1 christos 797 1.1 christos <p class="noindent">This option has some usage constraints. It: 798 1.1 christos <ul> 799 1.1 christos <li>must be compiled in by defining <code>HAVE_DROPROOT</code> during the compilation. 800 1.1 christos </ul> 801 1.1 christos 802 1.1 christos <p>Specify a user, and optionally a group, to switch to. 803 1.1 christos This option is only available if the OS supports adjusting the clock 804 1.1 christos without full root privileges. 805 1.1 christos This option is supported under NetBSD (configure with 806 1.1 christos <code>--enable-clockctl</code>) or Linux (configure with 807 1.1 christos <code>--enable-linuxcaps</code>) or Solaris (configure with <code>--enable-solarisprivs</code>). 808 1.1 christos <div class="node"> 809 1.1 christos <p><hr> 810 1.1.1.6 christos <a name="ntpd-updateinterval"></a> 811 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-wait_002dsync">ntpd wait-sync</a>, 812 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-user">ntpd user</a>, 813 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 814 1.1.1.6 christos 815 1.1 christos </div> 816 1.1 christos 817 1.1 christos <h4 class="subsection">updateinterval option (-U)</h4> 818 1.1 christos 819 1.1.1.3 christos <p><a name="index-ntpd_002dupdateinterval-27"></a> 820 1.1 christos This is the “interval in seconds between scans for new or dropped interfaces” option. 821 1.1 christos This option takes a number argument. 822 1.1 christos Give the time in seconds between two scans for new or dropped interfaces. 823 1.1 christos For systems with routing socket support the scans will be performed shortly after the interface change 824 1.1 christos has been detected by the system. 825 1.1 christos Use 0 to disable scanning. 60 seconds is the minimum time between scans. 826 1.1 christos <div class="node"> 827 1.1 christos <p><hr> 828 1.1.1.6 christos <a name="ntpd-wait-sync"></a> 829 1.1.1.6 christos <a name="ntpd-wait_002dsync"></a> 830 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-slew">ntpd slew</a>, 831 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-updateinterval">ntpd updateinterval</a>, 832 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 833 1.1.1.6 christos 834 1.1 christos </div> 835 1.1 christos 836 1.1 christos <h4 class="subsection">wait-sync option (-w)</h4> 837 1.1 christos 838 1.1.1.3 christos <p><a name="index-ntpd_002dwait_002dsync-28"></a> 839 1.1 christos This is the “seconds to wait for first clock sync” option. 840 1.1 christos This option takes a number argument. 841 1.1 christos 842 1.1 christos <p class="noindent">This option has some usage constraints. It: 843 1.1 christos <ul> 844 1.1 christos <li>must be compiled in by defining <code>HAVE_WORKING_FORK</code> during the compilation. 845 1.1 christos <li>must not appear in combination with any of the following options: 846 1.1 christos nofork, quit, saveconfigquit. 847 1.1 christos </ul> 848 1.1 christos 849 1.1 christos <p>If greater than zero, alters <code>ntpd</code>'s behavior when forking to 850 1.1 christos daemonize. Instead of exiting with status 0 immediately after 851 1.1 christos the fork, the parent waits up to the specified number of 852 1.1 christos seconds for the child to first synchronize the clock. The exit 853 1.1 christos status is zero (success) if the clock was synchronized, 854 1.1 christos otherwise it is <code>ETIMEDOUT</code>. 855 1.1 christos This provides the option for a script starting <code>ntpd</code> to easily 856 1.1 christos wait for the first set of the clock before proceeding. 857 1.1 christos <div class="node"> 858 1.1 christos <p><hr> 859 1.1.1.6 christos <a name="ntpd-slew"></a> 860 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-usepcc">ntpd usepcc</a>, 861 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-wait_002dsync">ntpd wait-sync</a>, 862 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 863 1.1.1.6 christos 864 1.1 christos </div> 865 1.1 christos 866 1.1 christos <h4 class="subsection">slew option (-x)</h4> 867 1.1 christos 868 1.1.1.3 christos <p><a name="index-ntpd_002dslew-29"></a> 869 1.1 christos This is the “slew up to 600 seconds” option. 870 1.1 christos Normally, 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. 871 1.1 christos This option sets the threshold to 600 s, which is well within the accuracy window to set the clock manually. 872 1.1 christos Note: 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. 873 1.1 christos Thus, an adjustment as much as 600 s will take almost 14 days to complete. 874 1.1 christos This option can be used with the 875 1.1 christos <code>-g</code> 876 1.1 christos and 877 1.1 christos <code>-q</code> 878 1.1 christos options. 879 1.1 christos See the 880 1.1 christos <code>tinker</code> 881 1.1 christos configuration file directive for other options. 882 1.1 christos Note: The kernel time discipline is disabled with this option. 883 1.1 christos <div class="node"> 884 1.1 christos <p><hr> 885 1.1.1.6 christos <a name="ntpd-usepcc"></a> 886 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-pccfreq">ntpd pccfreq</a>, 887 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-slew">ntpd slew</a>, 888 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 889 1.1.1.6 christos 890 1.1 christos </div> 891 1.1 christos 892 1.1 christos <h4 class="subsection">usepcc option</h4> 893 1.1 christos 894 1.1.1.3 christos <p><a name="index-ntpd_002dusepcc-30"></a> 895 1.1 christos This is the “use cpu cycle counter (windows only)” option. 896 1.1 christos 897 1.1 christos <p class="noindent">This option has some usage constraints. It: 898 1.1 christos <ul> 899 1.1 christos <li>must be compiled in by defining <code>SYS_WINNT</code> during the compilation. 900 1.1 christos </ul> 901 1.1 christos 902 1.1 christos <p>Attempt to substitute the CPU counter for <code>QueryPerformanceCounter</code>. 903 1.1 christos The CPU counter and <code>QueryPerformanceCounter</code> are compared, and if 904 1.1 christos they have the same frequency, the CPU counter (RDTSC on x86) is 905 1.1 christos used directly, saving the overhead of a system call. 906 1.1 christos <div class="node"> 907 1.1 christos <p><hr> 908 1.1.1.6 christos <a name="ntpd-pccfreq"></a> 909 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-mdns">ntpd mdns</a>, 910 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-usepcc">ntpd usepcc</a>, 911 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 912 1.1.1.6 christos 913 1.1 christos </div> 914 1.1 christos 915 1.1 christos <h4 class="subsection">pccfreq option</h4> 916 1.1 christos 917 1.1.1.3 christos <p><a name="index-ntpd_002dpccfreq-31"></a> 918 1.1 christos This is the “force cpu cycle counter use (windows only)” option. 919 1.1 christos This option takes a string argument. 920 1.1 christos 921 1.1 christos <p class="noindent">This option has some usage constraints. It: 922 1.1 christos <ul> 923 1.1 christos <li>must be compiled in by defining <code>SYS_WINNT</code> during the compilation. 924 1.1 christos </ul> 925 1.1 christos 926 1.1 christos <p>Force substitution the CPU counter for <code>QueryPerformanceCounter</code>. 927 1.1 christos The CPU counter (RDTSC on x86) is used unconditionally with the 928 1.1 christos given frequency (in Hz). 929 1.1 christos <div class="node"> 930 1.1 christos <p><hr> 931 1.1.1.6 christos <a name="ntpd-mdns"></a> 932 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-config">ntpd config</a>, 933 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-pccfreq">ntpd pccfreq</a>, 934 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 935 1.1.1.6 christos 936 1.1 christos </div> 937 1.1 christos 938 1.1 christos <h4 class="subsection">mdns option (-m)</h4> 939 1.1 christos 940 1.1.1.3 christos <p><a name="index-ntpd_002dmdns-32"></a> 941 1.1 christos This is the “register with mdns as a ntp server” option. 942 1.1 christos 943 1.1 christos <p class="noindent">This option has some usage constraints. It: 944 1.1 christos <ul> 945 1.1 christos <li>must be compiled in by defining <code>HAVE_DNSREGISTRATION</code> during the compilation. 946 1.1 christos </ul> 947 1.1 christos 948 1.1 christos <p>Registers as an NTP server with the local mDNS server which allows 949 1.1 christos the server to be discovered via mDNS client lookup. 950 1.1 christos 951 1.1 christos <div class="node"> 952 1.1 christos <p><hr> 953 1.1.1.6 christos <a name="ntpd-config"></a> 954 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-exit-status">ntpd exit status</a>, 955 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-mdns">ntpd mdns</a>, 956 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 957 1.1.1.6 christos 958 1.1 christos </div> 959 1.1 christos 960 1.1 christos <h4 class="subsection">presetting/configuring ntpd</h4> 961 1.1 christos 962 1.1 christos <p>Any option that is not marked as <i>not presettable</i> may be preset by 963 1.1 christos loading values from environment variables named <code>NTPD</code> and <code>NTPD_<OPTION_NAME></code>. <code><OPTION_NAME></code> must be one of 964 1.1 christos the options listed above in upper case and segmented with underscores. 965 1.1 christos The <code>NTPD</code> variable will be tokenized and parsed like 966 1.1 christos the command line. The remaining variables are tested for existence and their 967 1.1 christos values are treated like option arguments. 968 1.1 christos 969 1.1 christos <p>The command line options relating to configuration and/or usage help are: 970 1.1 christos 971 1.1 christos <h5 class="subsubheading">version (-)</h5> 972 1.1 christos 973 1.1 christos <p>Print the program version to standard out, optionally with licensing 974 1.1 christos information, then exit 0. The optional argument specifies how much licensing 975 1.1 christos detail to provide. The default is to print just the version. The licensing infomation may be selected with an option argument. 976 1.1 christos Only the first letter of the argument is examined: 977 1.1 christos 978 1.1 christos <dl> 979 1.1.1.6 christos <dt>`<samp><span class="samp">version</span></samp>'<dd>Only print the version. This is the default. 980 1.1.1.6 christos <br><dt>`<samp><span class="samp">copyright</span></samp>'<dd>Name the copyright usage licensing terms. 981 1.1.1.6 christos <br><dt>`<samp><span class="samp">verbose</span></samp>'<dd>Print the full copyright usage licensing terms. 982 1.1 christos </dl> 983 1.1 christos 984 1.1 christos <div class="node"> 985 1.1 christos <p><hr> 986 1.1.1.6 christos <a name="ntpd-exit-status"></a> 987 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-Usage">ntpd Usage</a>, 988 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-config">ntpd config</a>, 989 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 990 1.1.1.6 christos 991 1.1 christos </div> 992 1.1 christos 993 1.1 christos <h4 class="subsection">ntpd exit status</h4> 994 1.1 christos 995 1.1 christos <p>One of the following exit values will be returned: 996 1.1 christos <dl> 997 1.1.1.6 christos <dt>`<samp><span class="samp">0 (EXIT_SUCCESS)</span></samp>'<dd>Successful program execution. 998 1.1.1.6 christos <br><dt>`<samp><span class="samp">1 (EXIT_FAILURE)</span></samp>'<dd>The operation failed or the command syntax was not valid. 999 1.1 christos </dl> 1000 1.1 christos <div class="node"> 1001 1.1 christos <p><hr> 1002 1.1.1.6 christos <a name="ntpd-Usage"></a> 1003 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-Files">ntpd Files</a>, 1004 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-exit-status">ntpd exit status</a>, 1005 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 1006 1.1.1.6 christos 1007 1.1 christos </div> 1008 1.1 christos 1009 1.1 christos <h4 class="subsection">ntpd Usage</h4> 1010 1.1 christos 1011 1.1 christos <div class="node"> 1012 1.1 christos <p><hr> 1013 1.1.1.6 christos <a name="ntpd-Files"></a> 1014 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-See-Also">ntpd See Also</a>, 1015 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-Usage">ntpd Usage</a>, 1016 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 1017 1.1.1.6 christos 1018 1.1 christos </div> 1019 1.1 christos 1020 1.1 christos <h4 class="subsection">ntpd Files</h4> 1021 1.1 christos 1022 1.1 christos <div class="node"> 1023 1.1 christos <p><hr> 1024 1.1.1.6 christos <a name="ntpd-See-Also"></a> 1025 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-Bugs">ntpd Bugs</a>, 1026 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-Files">ntpd Files</a>, 1027 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 1028 1.1.1.6 christos 1029 1.1 christos </div> 1030 1.1 christos 1031 1.1 christos <h4 class="subsection">ntpd See Also</h4> 1032 1.1 christos 1033 1.1 christos <div class="node"> 1034 1.1 christos <p><hr> 1035 1.1.1.6 christos <a name="ntpd-Bugs"></a> 1036 1.1.1.6 christos Next: <a rel="next" accesskey="n" href="#ntpd-Notes">ntpd Notes</a>, 1037 1.1 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-See-Also">ntpd See Also</a>, 1038 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 1039 1.1.1.6 christos 1040 1.1 christos </div> 1041 1.1 christos 1042 1.1 christos <h4 class="subsection">ntpd Bugs</h4> 1043 1.1 christos 1044 1.1 christos <div class="node"> 1045 1.1 christos <p><hr> 1046 1.1.1.6 christos <a name="ntpd-Notes"></a> 1047 1.1.1.6 christos Previous: <a rel="previous" accesskey="p" href="#ntpd-Bugs">ntpd Bugs</a>, 1048 1.1 christos Up: <a rel="up" accesskey="u" href="#ntpd-Invocation">ntpd Invocation</a> 1049 1.1.1.6 christos 1050 1.1 christos </div> 1051 1.1 christos 1052 1.1 christos <h4 class="subsection">ntpd Notes</h4> 1053 1.1 christos 1054 1.1 christos <div class="node"> 1055 1.1 christos <p><hr> 1056 1.1 christos <a name="Usage"></a> 1057 1.1.1.6 christos 1058 1.1.1.6 christos 1059 1.1 christos </div> 1060 1.1 christos 1061 1.1 christos <!-- node-name, next, previous, up --> 1062 1.1 christos <h3 class="section">Usage</h3> 1063 1.1 christos 1064
Indexes created Wed Apr 15 00:22:22 UTC 2026