.TH NTPD 1 2009-12-10 "( 4.2.6)" "Programmer's Manual"
.\" EDIT THIS FILE WITH CAUTION (ntpd.1)
.\"
.\" It has been AutoGen-ed December 10, 2009 at 04:56:49 AM by AutoGen 5.10
.\" From the definitions ntpd-opts.def
.\" and the template file agman1.tpl
.\"
.SH NAME
ntpd \- NTP daemon program
.SH SYNOPSIS
.B ntpd
.\" Mixture of short (flag) options and long options
.RB [ \-\fIflag\fP " [\fIvalue\fP]]... [" \--\fIopt-name\fP " [[=| ]\fIvalue\fP]]..."
.PP
All arguments must be options.
.SH "DESCRIPTION"
This manual page briefly documents the \fBntpd\fP command.
.SH OPTIONS
.TP
.BR \-4 ", " \--ipv4
Force IPv4 DNS name resolution.
This option must not appear in combination with any of the following options:
ipv6.
.sp
Force DNS resolution of following host names on the command line
to the IPv4 namespace.
.TP
.BR \-6 ", " \--ipv6
Force IPv6 DNS name resolution.
This option must not appear in combination with any of the following options:
ipv4.
.sp
Force DNS resolution of following host names on the command line
to the IPv6 namespace.
.TP
.BR \-a ", " \--authreq
Require crypto authentication.
This option must not appear in combination with any of the following options:
authnoreq.
.sp
Require cryptographic authentication for broadcast client,
multicast client and symmetric passive associations.
This is the default.
.TP
.BR \-A ", " \--authnoreq
Do not require crypto authentication.
This option must not appear in combination with any of the following options:
authreq.
.sp
Do not require cryptographic authentication for broadcast client,
multicast client and symmetric passive associations.
This is almost never a good idea.
.TP
.BR \-b ", " \--bcastsync
Allow us to sync to broadcast servers.
.sp
.TP
.BR \-c " \fIstring\fP, " \--configfile "=" \fIstring\fP
configuration file name.
.sp
The name and path of the configuration file,
/etc/ntp.conf
by default.
.TP
.BR \-d ", " \--debug-level
Increase output debug message level.
This option may appear an unlimited number of times.
.sp
Increase the debugging message output level.
.TP
.BR \-D " \fIstring\fP, " \--set-debug-level "=" \fIstring\fP
Set the output debug message level.
This option may appear an unlimited number of times.
.sp
Set the output debugging level. Can be supplied multiple times,
but each overrides the previous value(s).
.TP
.BR \-f " \fIstring\fP, " \--driftfile "=" \fIstring\fP
frequency drift file name.
.sp
The name and path of the frequency file,
/etc/ntp.drift
by default.
This is the same operation as the
driftfile driftfile
configuration specification in the
/etc/ntp.conf
file.
.TP
.BR \-g ", " \--panicgate
Allow the first adjustment to be Big.
This option may appear an unlimited number of times.
.sp
Normally,
ntpd
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,
ntpd
will exit with a message to the system log. This option can be used with the
-q
and
-x
options.
See the
tinker
configuration file directive for other options.
.TP
.BR \-i " \fIstring\fP, " \--jaildir "=" \fIstring\fP
Jail directory.
.sp
Chroot the server to the directory
jaildir
.
This option also implies that the server attempts to drop root privileges at startup.
You may need to also specify a
-u
option.
This option is only available if the OS supports adjusting the clock
without full root privileges.
This option is supported under NetBSD (configure with
--enable-clockctl
) and Linux (configure with
--enable-linuxcaps
).
.TP
.BR \-I " \fIiface\fP, " \--interface "=" \fIiface\fP
Listen on an interface name or address.
This option may appear an unlimited number of times.
.sp
Open the network address given, or all the addresses associated with the
given interface name. This option may appear multiple times. This option
also implies not opening other addresses, except wildcard and localhost.
This option is deprecated. Please consider using the configuration file
interface command, which is more versatile.
.TP
.BR \-k " \fIstring\fP, " \--keyfile "=" \fIstring\fP
path to symmetric keys.
.sp
Specify the name and path of the symmetric key file.
/etc/ntp.keys
is the default.
This is the same operation as the
keys keyfile
configuration file directive.
.TP
.BR \-l " \fIstring\fP, " \--logfile "=" \fIstring\fP
path to the log file.
.sp
Specify the name and path of the log file.
The default is the system log file.
This is the same operation as the
logfile logfile
configuration file directive.
.TP
.BR \-L ", " \--novirtualips
Do not listen to virtual interfaces.
.sp
Do not listen to virtual interfaces, defined as those with
names containing a colon. This option is deprecated. Please
consider using the configuration file interface command, which
is more versatile.
.TP
.BR \-M ", " \--modifymmtimer
Modify Multimedia Timer (Windows only).
.sp
Set the Windows Multimedia Timer to highest resolution. This
ensures the resolution does not change while ntpd is running,
avoiding timekeeping glitches associated with changes.
.TP
.BR \-n ", " \--nofork
Do not fork.
.sp
.TP
.BR \-N ", " \--nice
Run at high priority.
.sp
To the extent permitted by the operating system, run
ntpd
at the highest priority.
.TP
.BR \-p " \fIstring\fP, " \--pidfile "=" \fIstring\fP
path to the PID file.
.sp
Specify the name and path of the file used to record
ntpd's
process ID.
This is the same operation as the
pidfile pidfile
configuration file directive.
.TP
.BR \-P " \fInumber\fP, " \--priority "=" \fInumber\fP
Process priority.
This option takes an integer number as its argument.
.sp
To the extent permitted by the operating system, run
ntpd
at the specified
sched_setscheduler(SCHED_FIFO)
priority.
.TP
.BR \-q ", " \--quit
Set the time and quit.
.sp
ntpd
will exit just after the first time the clock is set. This behavior mimics that of the
ntpdate
program, which is to be retired.
The
-g
and
-x
options can be used with this option.
Note: The kernel time discipline is disabled with this option.
.TP
.BR \-r " \fIstring\fP, " \--propagationdelay "=" \fIstring\fP
Broadcast/propagation delay.
.sp
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.
.TP
.BR \--saveconfigquit "=\fIstring\fP"
Save parsed configuration and quit.
.sp
Cause ntpd to parse its startup configuration file and save an
equivalent to the given filename and exit. This option was
designed for automated testing.
.TP
.BR \-s " \fIstring\fP, " \--statsdir "=" \fIstring\fP
Statistics file location.
.sp
Specify the directory path for files created by the statistics facility.
This is the same operation as the
statsdir statsdir
configuration file directive.
.TP
.BR \-t " \fItkey\fP, " \--trustedkey "=" \fItkey\fP
Trusted key number.
This option may appear an unlimited number of times.
.sp
Add a key number to the trusted key list.
.TP
.BR \-u " \fIstring\fP, " \--user "=" \fIstring\fP
Run as userid (or userid:groupid).
.sp
Specify a user, and optionally a group, to switch to.
This option is only available if the OS supports adjusting the clock
without full root privileges.
This option is supported under NetBSD (configure with
--enable-clockctl
) and Linux (configure with
--enable-linuxcaps
).
.TP
.BR \-U " \fInumber\fP, " \--updateinterval "=" \fInumber\fP
interval in seconds between scans for new or dropped interfaces.
This option takes an integer number as its argument.
.sp
Give the time in seconds between two scans for new or dropped interfaces.
For systems with routing socket support the scans will be performed shortly after the interface change
has been detected by the system.
Use 0 to disable scanning. 60 seconds is the minimum time between scans.
.TP
.BR \--var "=\fInvar\fP"
make ARG an ntp variable (RW).
This option may appear an unlimited number of times.
.sp
.TP
.BR \--dvar "=\fIndvar\fP"
make ARG an ntp variable (RW|DEF).
This option may appear an unlimited number of times.
.sp
.TP
.BR \-x ", " \--slew
Slew up to 600 seconds.
.sp
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.
This option sets the threshold to 600 s, which is well within the accuracy window to set the clock manually.
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.
Thus, an adjustment as much as 600 s will take almost 14 days to complete.
This option can be used with the
-g
and
-q
options.
See the
tinker
configuration file directive for other options.
Note: The kernel time discipline is disabled with this option.
.TP
.BR \--usepcc
Use CPU cycle counter (Windows only).
.sp
Attempt to substitute the CPU counter for QueryPerformanceCounter.
The CPU counter and QueryPerformanceCounter are compared, and if
they have the same frequency, the CPU counter (RDTSC on x86) is
used directly, saving the overhead of a system call.
.TP
.BR \--pccfreq "=\fIstring\fP"
Force CPU cycle counter use (Windows only).
.sp
Force substitution the CPU counter for QueryPerformanceCounter.
The CPU counter (RDTSC on x86) is used unconditionally with the
given frequency (in Hz).
.TP
.BR \-? , " \--help"
Display extended usage information and exit.
.TP
.BR \-! , " \--more-help"
Extended usage information passed thru pager.
.TP
.BR \- " [{\fIv|c|n\fP}]," " \--version" "[=\fI{v|c|n}\fP]"
Output version of program and exit. The default mode is `v', a simple
version. The `c' mode will print copyright information and `n' will
print the full copyright notice.
.SH OPTION PRESETS
Any option that is not marked as \fInot presettable\fP may be preset
by loading values from environment variables named:
.nf
\fBNTPD_<option-name>\fP or \fBNTPD\fP
.fi
.ad
.SH AUTHOR
David L. Mills and/or others
.br
Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.PP
.nf
.na
see html/copyright.html
.fi
.ad
.PP
This manual page was \fIAutoGen\fP-erated from the \fBntpd\fP
option definitions.