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 documents, briefly, the ntpd command.


OPTIONS
       -4, --ipv4
              Force  IPv4 DNS name resolution.  This option is a member of the
              ipv4 class of options.

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

       -6, --ipv6
              Force  IPv6 DNS name resolution.  This option is a member of the
              ipv4 class of options.

              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.

              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 (otherwise, chroot gives very  little  additional  secu-
              rity),  and  it  is only available if the OS supports to run the
              server without full root privileges.  You may need to also spec-
              ify a -u option.

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



       -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 IPs.

              Do not listen to virtual IPs. The default is to listen.

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

              Set the Windows Multimedia Timer to highest resolution.

       -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.

       -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.

       -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 to  run  the  server
              without  full  root  privileges.  Currently, this option is sup-
              ported under NetBSD  (configure  with  --enable-clockctl  )  and
              Linux (configure with --enable-linuxcaps ).

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



       -V ndvar, --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.

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

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

       -v [{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.isc.org, bugs@ntp.org


       see /usr/share/doc/html/ntp/copyright.html

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



( 4.2.4p6)                        2009-01-08                           NTPD(8)

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