1 .TH NTPD 1 2009-12-08 "( 4.2.4p8)" "Programmer's Manual"
2 .\" EDIT THIS FILE WITH CAUTION (ntpd.1)
4 .\" It has been AutoGen-ed Tuesday December 8, 2009 at 08:13:11 AM EST
5 .\" From the definitions ntpd-opts.def
6 .\" and the template file agman1.tpl
9 ntpd \- NTP daemon program
12 .\" Mixture of short (flag) options and long options
13 .RB [ \-\fIflag\fP " [\fIvalue\fP]]... [" \--\fIopt-name\fP " [[=| ]\fIvalue\fP]]..."
15 All arguments must be options.
17 This manual page documents, briefly, the \fBntpd\fP command.
22 Force IPv4 DNS name resolution.
23 This option is a member of the ipv4 class of options.
25 Force DNS resolution of following host names on the command line
26 to the IPv4 namespace.
29 Force IPv6 DNS name resolution.
30 This option is a member of the ipv4 class of options.
32 Force DNS resolution of following host names on the command line
33 to the IPv6 namespace.
35 .BR \-a ", " \--authreq
36 Require crypto authentication.
37 This option must not appear in combination with any of the following options:
40 Require cryptographic authentication for broadcast client,
41 multicast client and symmetric passive associations.
44 .BR \-A ", " \--authnoreq
45 Do not require crypto authentication.
46 This option must not appear in combination with any of the following options:
49 Do not require cryptographic authentication for broadcast client,
50 multicast client and symmetric passive associations.
51 This is almost never a good idea.
53 .BR \-b ", " \--bcastsync
54 Allow us to sync to broadcast servers.
58 .BR \-c " \fIstring\fP, " \--configfile "=" \fIstring\fP
59 configuration file name.
61 The name and path of the configuration file,
65 .BR \-d ", " \--debug-level
66 Increase output debug message level.
67 This option may appear an unlimited number of times.
69 Increase the debugging message output level.
71 .BR \-D " \fIstring\fP, " \--set-debug-level "=" \fIstring\fP
72 Set the output debug message level.
73 This option may appear an unlimited number of times.
75 Set the output debugging level. Can be supplied multiple times,
76 but each overrides the previous value(s).
78 .BR \-f " \fIstring\fP, " \--driftfile "=" \fIstring\fP
79 frequency drift file name.
81 The name and path of the frequency file,
84 This is the same operation as the
86 configuration specification in the
90 .BR \-g ", " \--panicgate
91 Allow the first adjustment to be Big.
95 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,
97 will exit with a message to the system log. This option can be used with the
104 configuration file directive for other options.
106 .BR \-i " \fIstring\fP, " \--jaildir "=" \fIstring\fP
109 Chroot the server to the directory
112 This option also implies that the server attempts to drop root privileges at startup (otherwise, chroot gives very little additional security), and it is only available if the OS supports to run the server without full root privileges.
113 You may need to also specify a
117 .BR \-I " \fIiface\fP, " \--interface "=" \fIiface\fP
119 This option may appear an unlimited number of times.
123 .BR \-k " \fIstring\fP, " \--keyfile "=" \fIstring\fP
124 path to symmetric keys.
126 Specify the name and path of the symmetric key file.
129 This is the same operation as the
131 configuration file directive.
133 .BR \-l " \fIstring\fP, " \--logfile "=" \fIstring\fP
134 path to the log file.
136 Specify the name and path of the log file.
137 The default is the system log file.
138 This is the same operation as the
140 configuration file directive.
142 .BR \-L ", " \--novirtualips
143 Do not listen to virtual IPs.
145 Do not listen to virtual IPs. The default is to listen.
147 .BR \-M ", " \--modifymmtimer
148 Modify Multimedia Timer (Windows only).
150 Set the Windows Multimedia Timer to highest resolution.
152 .BR \-n ", " \--nofork
158 Run at high priority.
160 To the extent permitted by the operating system, run
162 at the highest priority.
164 .BR \-p " \fIstring\fP, " \--pidfile "=" \fIstring\fP
165 path to the PID file.
167 Specify the name and path of the file used to record
170 This is the same operation as the
172 configuration file directive.
174 .BR \-P " \fInumber\fP, " \--priority "=" \fInumber\fP
176 This option takes an integer number as its argument.
178 To the extent permitted by the operating system, run
181 sched_setscheduler(SCHED_FIFO)
185 Set the time and quit.
188 will exit just after the first time the clock is set. This behavior mimics that of the
190 program, which is to be retired.
195 options can be used with this option.
196 Note: The kernel time discipline is disabled with this option.
198 .BR \-r " \fIstring\fP, " \--propagationdelay "=" \fIstring\fP
199 Broadcast/propagation delay.
201 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.
203 .BR \-U " \fInumber\fP, " \--updateinterval "=" \fInumber\fP
204 interval in seconds between scans for new or dropped interfaces.
205 This option takes an integer number as its argument.
207 Give the time in seconds between two scans for new or dropped interfaces.
208 For systems with routing socket support the scans will be performed shortly after the interface change
209 has been detected by the system.
210 Use 0 to disable scanning.
212 .BR \-s " \fIstring\fP, " \--statsdir "=" \fIstring\fP
213 Statistics file location.
215 Specify the directory path for files created by the statistics facility.
216 This is the same operation as the
218 configuration file directive.
220 .BR \-t " \fItkey\fP, " \--trustedkey "=" \fItkey\fP
222 This option may appear an unlimited number of times.
224 Add a key number to the trusted key list.
226 .BR \-u " \fIstring\fP, " \--user "=" \fIstring\fP
227 Run as userid (or userid:groupid).
229 Specify a user, and optionally a group, to switch to.
230 This option is only available if the OS supports to run the server without full root privileges.
231 Currently, this option is supported under NetBSD (configure with
233 ) and Linux (configure with
237 .BR \-v " \fInvar\fP, " \--var "=" \fInvar\fP
238 make ARG an ntp variable (RW).
239 This option may appear an unlimited number of times.
243 .BR \-V " \fIndvar\fP, " \--dvar "=" \fIndvar\fP
244 make ARG an ntp variable (RW|DEF).
245 This option may appear an unlimited number of times.
250 Slew up to 600 seconds.
252 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.
253 This option sets the threshold to 600 s, which is well within the accuracy window to set the clock manually.
254 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.
255 Thus, an adjustment as much as 600 s will take almost 14 days to complete.
256 This option can be used with the
263 configuration file directive for other options.
264 Note: The kernel time discipline is disabled with this option.
267 Display usage information and exit.
269 .BR \-! , " \--more-help"
270 Extended usage information passed thru pager.
272 .BR \-v " [{\fIv|c|n\fP}]," " \--version" "[=\fI{v|c|n}\fP]"
273 Output version of program and exit. The default mode is `v', a simple
274 version. The `c' mode will print copyright information and `n' will
275 print the full copyright notice.
277 Any option that is not marked as \fInot presettable\fP may be preset
278 by loading values from environment variables named:
280 \fBNTPD_<option-name>\fP or \fBNTPD\fP
284 David L. Mills and/or others
286 Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
291 see /usr/share/doc/html/ntp/copyright.html
295 This manual page was \fIAutoGen\fP-erated from the \fBntpd\fP