4 @cindex NTP daemon program
7 # EDIT THIS FILE WITH CAUTION (ntpd-opts.texi)
9 # It has been AutoGen-ed December 10, 2009 at 05:01:23 AM by AutoGen 5.10
10 # From the definitions ntpd-opts.def
11 # and the template file aginfo.tpl
13 This program has no explanation.
17 This section was generated by @strong{AutoGen},
18 the aginfo template and the option descriptions for the @command{ntpd} program. It documents the ntpd usage text and option meanings.
20 This software is released under a specialized copyright license.
23 * ntpd usage:: ntpd usage help (-?)
24 * ntpd authnoreq:: authnoreq option (-A)
25 * ntpd authreq:: authreq option (-a)
26 * ntpd bcastsync:: bcastsync option (-b)
27 * ntpd configfile:: configfile option (-c)
28 * ntpd debug-level:: debug-level option (-d)
29 * ntpd driftfile:: driftfile option (-f)
30 * ntpd dvar:: dvar option
31 * ntpd interface:: interface option (-I)
32 * ntpd ipv4:: ipv4 option (-4)
33 * ntpd ipv6:: ipv6 option (-6)
34 * ntpd jaildir:: jaildir option (-i)
35 * ntpd keyfile:: keyfile option (-k)
36 * ntpd logfile:: logfile option (-l)
37 * ntpd modifymmtimer:: modifymmtimer option (-M)
38 * ntpd nice:: nice option (-N)
39 * ntpd nofork:: nofork option (-n)
40 * ntpd novirtualips:: novirtualips option (-L)
41 * ntpd panicgate:: panicgate option (-g)
42 * ntpd pccfreq:: pccfreq option
43 * ntpd pidfile:: pidfile option (-p)
44 * ntpd priority:: priority option (-P)
45 * ntpd propagationdelay:: propagationdelay option (-r)
46 * ntpd quit:: quit option (-q)
47 * ntpd saveconfigquit:: saveconfigquit option
48 * ntpd set-debug-level:: set-debug-level option (-D)
49 * ntpd slew:: slew option (-x)
50 * ntpd statsdir:: statsdir option (-s)
51 * ntpd trustedkey:: trustedkey option (-t)
52 * ntpd updateinterval:: updateinterval option (-U)
53 * ntpd usepcc:: usepcc option
54 * ntpd user:: user option (-u)
55 * ntpd var:: var option
59 @subsection ntpd usage help (-?)
62 This is the automatically generated usage text for ntpd:
66 ntpd - NTP daemon program - Ver. 4.2.6
67 USAGE: ntpd [ -<flag> [<val>] | --<name>[@{=| @}<val>] ]...
68 Flg Arg Option-Name Description
69 -4 no ipv4 Force IPv4 DNS name resolution
70 - prohibits these options:
72 -6 no ipv6 Force IPv6 DNS name resolution
73 - prohibits these options:
75 -a no authreq Require crypto authentication
76 - prohibits these options:
78 -A no authnoreq Do not require crypto authentication
79 - prohibits these options:
81 -b no bcastsync Allow us to sync to broadcast servers
82 -c Str configfile configuration file name
83 -d no debug-level Increase output debug message level
84 - may appear multiple times
85 -D Str set-debug-level Set the output debug message level
86 - may appear multiple times
87 -f Str driftfile frequency drift file name
88 -g no panicgate Allow the first adjustment to be Big
89 - may appear multiple times
90 -i --- jaildir built without --enable-clockctl or --enable-linuxcaps
91 -I Str interface Listen on an interface name or address
92 - may appear multiple times
93 -k Str keyfile path to symmetric keys
94 -l Str logfile path to the log file
95 -L no novirtualips Do not listen to virtual interfaces
96 -n no nofork Do not fork
97 -N no nice Run at high priority
98 -p Str pidfile path to the PID file
99 -P Num priority Process priority
100 -q no quit Set the time and quit
101 -r Str propagationdelay Broadcast/propagation delay
102 Str saveconfigquit Save parsed configuration and quit
103 -s Str statsdir Statistics file location
104 -t Str trustedkey Trusted key number
105 - may appear multiple times
106 -u --- user built without --enable-clockctl or --enable-linuxcaps
107 -U Num updateinterval interval in seconds between scans for new or dropped interfaces
108 Str var make ARG an ntp variable (RW)
109 - may appear multiple times
110 Str dvar make ARG an ntp variable (RW|DEF)
111 - may appear multiple times
112 -x no slew Slew up to 600 seconds
113 opt version Output version information and exit
114 -? no help Display extended usage information and exit
115 -! no more-help Extended usage information passed thru pager
117 Options are specified by doubled hyphens and their name
118 or by a single hyphen and the flag character.
120 The following option preset mechanisms are supported:
121 - examining environment variables named NTPD_*
125 please send bug reports to: http://bugs.ntp.org, bugs@@ntp.org
130 @subsection ipv4 option (-4)
133 This is the ``force ipv4 dns name resolution'' option.
135 This option has some usage constraints. It:
138 must not appear in combination with any of the following options:
142 Force DNS resolution of following host names on the command line
143 to the IPv4 namespace.
146 @subsection ipv6 option (-6)
149 This is the ``force ipv6 dns name resolution'' option.
151 This option has some usage constraints. It:
154 must not appear in combination with any of the following options:
158 Force DNS resolution of following host names on the command line
159 to the IPv6 namespace.
162 @subsection authreq option (-a)
165 This is the ``require crypto authentication'' option.
167 This option has some usage constraints. It:
170 must not appear in combination with any of the following options:
174 Require cryptographic authentication for broadcast client,
175 multicast client and symmetric passive associations.
179 @subsection authnoreq option (-A)
180 @cindex ntpd-authnoreq
182 This is the ``do not require crypto authentication'' option.
184 This option has some usage constraints. It:
187 must not appear in combination with any of the following options:
191 Do not require cryptographic authentication for broadcast client,
192 multicast client and symmetric passive associations.
193 This is almost never a good idea.
196 @subsection bcastsync option (-b)
197 @cindex ntpd-bcastsync
199 This is the ``allow us to sync to broadcast servers'' option.
202 @node ntpd configfile
203 @subsection configfile option (-c)
204 @cindex ntpd-configfile
206 This is the ``configuration file name'' option.
207 The name and path of the configuration file,
211 @node ntpd debug-level
212 @subsection debug-level option (-d)
213 @cindex ntpd-debug-level
215 This is the ``increase output debug message level'' option.
217 This option has some usage constraints. It:
220 may appear an unlimited number of times.
222 must be compiled in by defining @code{DEBUG} during the compilation.
225 Increase the debugging message output level.
227 @node ntpd set-debug-level
228 @subsection set-debug-level option (-D)
229 @cindex ntpd-set-debug-level
231 This is the ``set the output debug message level'' option.
233 This option has some usage constraints. It:
236 may appear an unlimited number of times.
238 must be compiled in by defining @code{DEBUG} during the compilation.
241 Set the output debugging level. Can be supplied multiple times,
242 but each overrides the previous value(s).
245 @subsection driftfile option (-f)
246 @cindex ntpd-driftfile
248 This is the ``frequency drift file name'' option.
249 The name and path of the frequency file,
252 This is the same operation as the
254 configuration specification in the
259 @subsection panicgate option (-g)
260 @cindex ntpd-panicgate
262 This is the ``allow the first adjustment to be big'' option.
264 This option has some usage constraints. It:
267 may appear an unlimited number of times.
272 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,
274 will exit with a message to the system log. This option can be used with the
281 configuration file directive for other options.
284 @subsection jaildir option (-i)
287 This is the ``jail directory'' option.
289 This option has some usage constraints. It:
292 must be compiled in by defining @code{HAVE_DROPROOT} during the compilation.
295 Chroot the server to the directory
298 This option also implies that the server attempts to drop root privileges at startup.
299 You may need to also specify a
302 This option is only available if the OS supports adjusting the clock
303 without full root privileges.
304 This option is supported under NetBSD (configure with
306 ) and Linux (configure with
311 @subsection interface option (-I)
312 @cindex ntpd-interface
314 This is the ``listen on an interface name or address'' option.
316 This option has some usage constraints. It:
319 may appear an unlimited number of times.
322 Open the network address given, or all the addresses associated with the
323 given interface name. This option may appear multiple times. This option
324 also implies not opening other addresses, except wildcard and localhost.
325 This option is deprecated. Please consider using the configuration file
326 interface command, which is more versatile.
329 @subsection keyfile option (-k)
332 This is the ``path to symmetric keys'' option.
333 Specify the name and path of the symmetric key file.
336 This is the same operation as the
338 configuration file directive.
341 @subsection logfile option (-l)
344 This is the ``path to the log file'' option.
345 Specify the name and path of the log file.
346 The default is the system log file.
347 This is the same operation as the
349 configuration file directive.
351 @node ntpd novirtualips
352 @subsection novirtualips option (-L)
353 @cindex ntpd-novirtualips
355 This is the ``do not listen to virtual interfaces'' option.
356 Do not listen to virtual interfaces, defined as those with
357 names containing a colon. This option is deprecated. Please
358 consider using the configuration file interface command, which
361 @node ntpd modifymmtimer
362 @subsection modifymmtimer option (-M)
363 @cindex ntpd-modifymmtimer
365 This is the ``modify multimedia timer (windows only)'' option.
367 This option has some usage constraints. It:
370 must be compiled in by defining @code{SYS_WINNT} during the compilation.
373 Set the Windows Multimedia Timer to highest resolution. This
374 ensures the resolution does not change while ntpd is running,
375 avoiding timekeeping glitches associated with changes.
378 @subsection nofork option (-n)
381 This is the ``do not fork'' option.
385 @subsection nice option (-N)
388 This is the ``run at high priority'' option.
389 To the extent permitted by the operating system, run
391 at the highest priority.
394 @subsection pidfile option (-p)
397 This is the ``path to the pid file'' option.
398 Specify the name and path of the file used to record
401 This is the same operation as the
403 configuration file directive.
406 @subsection priority option (-P)
407 @cindex ntpd-priority
409 This is the ``process priority'' option.
410 To the extent permitted by the operating system, run
413 sched_setscheduler(SCHED_FIFO)
417 @subsection quit option (-q)
420 This is the ``set the time and quit'' option.
422 will exit just after the first time the clock is set. This behavior mimics that of the
424 program, which is to be retired.
429 options can be used with this option.
430 Note: The kernel time discipline is disabled with this option.
432 @node ntpd propagationdelay
433 @subsection propagationdelay option (-r)
434 @cindex ntpd-propagationdelay
436 This is the ``broadcast/propagation delay'' option.
437 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.
439 @node ntpd saveconfigquit
440 @subsection saveconfigquit option
441 @cindex ntpd-saveconfigquit
443 This is the ``save parsed configuration and quit'' option.
445 This option has some usage constraints. It:
448 must be compiled in by defining @code{SAVECONFIG} during the compilation.
451 Cause ntpd to parse its startup configuration file and save an
452 equivalent to the given filename and exit. This option was
453 designed for automated testing.
456 @subsection statsdir option (-s)
457 @cindex ntpd-statsdir
459 This is the ``statistics file location'' option.
460 Specify the directory path for files created by the statistics facility.
461 This is the same operation as the
463 configuration file directive.
465 @node ntpd trustedkey
466 @subsection trustedkey option (-t)
467 @cindex ntpd-trustedkey
469 This is the ``trusted key number'' option.
471 This option has some usage constraints. It:
474 may appear an unlimited number of times.
477 Add a key number to the trusted key list.
480 @subsection user option (-u)
483 This is the ``run as userid (or userid:groupid)'' option.
485 This option has some usage constraints. It:
488 must be compiled in by defining @code{HAVE_DROPROOT} during the compilation.
491 Specify a user, and optionally a group, to switch to.
492 This option is only available if the OS supports adjusting the clock
493 without full root privileges.
494 This option is supported under NetBSD (configure with
496 ) and Linux (configure with
500 @node ntpd updateinterval
501 @subsection updateinterval option (-U)
502 @cindex ntpd-updateinterval
504 This is the ``interval in seconds between scans for new or dropped interfaces'' option.
505 Give the time in seconds between two scans for new or dropped interfaces.
506 For systems with routing socket support the scans will be performed shortly after the interface change
507 has been detected by the system.
508 Use 0 to disable scanning. 60 seconds is the minimum time between scans.
511 @subsection var option
514 This is the ``make arg an ntp variable (rw)'' option.
516 This option has some usage constraints. It:
519 may appear an unlimited number of times.
525 @subsection dvar option
528 This is the ``make arg an ntp variable (rw|def)'' option.
530 This option has some usage constraints. It:
533 may appear an unlimited number of times.
539 @subsection slew option (-x)
542 This is the ``slew up to 600 seconds'' option.
543 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.
544 This option sets the threshold to 600 s, which is well within the accuracy window to set the clock manually.
545 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.
546 Thus, an adjustment as much as 600 s will take almost 14 days to complete.
547 This option can be used with the
554 configuration file directive for other options.
555 Note: The kernel time discipline is disabled with this option.
558 @subsection usepcc option
561 This is the ``use cpu cycle counter (windows only)'' option.
563 This option has some usage constraints. It:
566 must be compiled in by defining @code{SYS_WINNT} during the compilation.
569 Attempt to substitute the CPU counter for QueryPerformanceCounter.
570 The CPU counter and QueryPerformanceCounter are compared, and if
571 they have the same frequency, the CPU counter (RDTSC on x86) is
572 used directly, saving the overhead of a system call.
575 @subsection pccfreq option
578 This is the ``force cpu cycle counter use (windows only)'' option.
580 This option has some usage constraints. It:
583 must be compiled in by defining @code{SYS_WINNT} during the compilation.
586 Force substitution the CPU counter for QueryPerformanceCounter.
587 The CPU counter (RDTSC on x86) is used unconditionally with the
588 given frequency (in Hz).