NTPD(8)                       Programmer's Manual                      NTPD(8)



NAME
       ntpd - NTP daemon program

SYNOPSIS
       ntpd [-flag [value]]... [--opt-name [[=| ]value]]...

       All arguments must be options.

DESCRIPTION
       This manual page briefly documents the ntpd command.


OPTIONS
       -4, --ipv4
              Force  IPv4 DNS name resolution.  This option must not appear in
              combination with any of the following options: ipv6.

              Force DNS resolution of following host names on the command line
              to the IPv4 namespace.

       -6, --ipv6
              Force  IPv6 DNS name resolution.  This option must not appear in
              combination with any of the following options: ipv4.

              Force DNS resolution of following host names on the command line
              to the IPv6 namespace.

       -a, --authreq
              Require  crypto  authentication.  This option must not appear in
              combination with any of the following options: authnoreq.

              Require cryptographic authentication for broadcast client,  mul-
              ticast  client  and symmetric passive associations.  This is the
              default.

       -A, --authnoreq
              Do not require crypto  authentication.   This  option  must  not
              appear  in  combination  with  any  of  the  following  options:
              authreq.

              Do  not  require  cryptographic  authentication  for   broadcast
              client,  multicast  client  and  symmetric passive associations.
              This is almost never a good idea.

       -b, --bcastsync
              Allow us to sync to broadcast servers.



       -c string, --configfile=string
              configuration file name.

              The name and path of the configuration  file,  /etc/ntp.conf  by
              default.

       -d, --debug-level
              Increase  output debug message level.  This option may appear an
              unlimited number of times.

              Increase the debugging message output level.

       -D string, --set-debug-level=string
              Set the output debug message level.  This option may  appear  an
              unlimited number of times.

              Set the output debugging level.  Can be supplied multiple times,
              but each overrides the previous value(s).

       -f string, --driftfile=string
              frequency drift file name.

              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.

       -g, --panicgate
              Allow the first adjustment to be Big.  This option may appear an
              unlimited number of times.

              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  thresh-
              old 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.

       -i string, --jaildir=string
              Jail directory.

              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 ).

       -I iface, --interface=iface
              Listen  on an interface name or address.  This option may appear
              an unlimited number of times.

              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.

       -k string, --keyfile=string
              path to symmetric keys.

              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.

       -l string, --logfile=string
              path to the log file.

              Specify  the  name and path of the log file.  The default is the
              system log file.  This is the same operation as the logfile log-
              file configuration file directive.

       -L, --novirtualips
              Do not listen to virtual interfaces.

              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.

       -M, --modifymmtimer
              Modify Multimedia Timer (Windows only).

              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.

       -n, --nofork
              Do not fork.



       -N, --nice
              Run at high priority.

              To the extent permitted by the operating system, run ntpd at the
              highest priority.

       -p string, --pidfile=string
              path to the PID file.

              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.

       -P number, --priority=number
              Process  priority.   This  option takes an integer number as its
              argument.

              To the extent permitted by the operating system, run ntpd at the
              specified sched_setscheduler(SCHED_FIFO) priority.

       -q, --quit
              Set the time and quit.

              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.

       -r string, --propagationdelay=string
              Broadcast/propagation delay.

              Specify the default propagation delay from the  broadcast/multi-
              cast  server to this client. This is necessary only if the delay
              cannot be computed automatically by the protocol.

       --saveconfigquit=string
              Save parsed configuration and quit.

              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.

       -s string, --statsdir=string
              Statistics file location.

              Specify the directory path for files created by  the  statistics
              facility.   This  is the same operation as the statsdir statsdir
              configuration file directive.

       -t tkey, --trustedkey=tkey
              Trusted key number.  This option may appear an unlimited  number
              of times.

              Add a key number to the trusted key list.

       -u string, --user=string
              Run as userid (or userid:groupid).

              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 ).

       -U number, --updateinterval=number
              interval in seconds between scans for new or dropped interfaces.
              This option takes an integer number as its argument.

              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.

       --var=nvar
              make ARG an ntp variable (RW).  This option may appear an unlim-
              ited number of times.



       --dvar=ndvar
              make  ARG  an  ntp variable (RW|DEF).  This option may appear an
              unlimited number of times.



       -x, --slew
              Slew up to 600 seconds.

              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 direc-
              tive  for  other  options.   Note: The kernel time discipline is
              disabled with this option.

       --usepcc
              Use CPU cycle counter (Windows only).

              Attempt to substitute  the  CPU  counter  for  QueryPerformance-
              Counter.   The  CPU counter and QueryPerformanceCounter are com-
              pared, and if they have the  same  frequency,  the  CPU  counter
              (RDTSC on x86) is used directly, saving the overhead of a system
              call.

       --pccfreq=string
              Force CPU cycle counter use (Windows only).

              Force substitution the CPU counter for  QueryPerformanceCounter.
              The  CPU counter (RDTSC on x86) is used unconditionally with the
              given frequency (in Hz).

       -?, --help
              Display extended usage information and exit.

       -!, --more-help
              Extended usage information passed thru pager.

       - [{v|c|n}], --version[={v|c|n}]
              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.

OPTION PRESETS
       Any option that is not marked as not presettable may be preset by load-
       ing values from environment variables named:
         NTPD_<option-name> or NTPD

AUTHOR
       David L. Mills and/or others
       Please send bug reports to:  http://bugs.ntp.org, bugs@ntp.org


       see html/copyright.html


       This manual page was AutoGen-erated from the ntpd option definitions.



( 4.2.6p5)                        2011-12-24                           NTPD(8)

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