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ntp_misc(5)		      File Formats Manual		   ntp_misc(5)



NAME
       ntp_misc - Miscellaneous Options


       broadcastdelay seconds
	       The broadcast and multicast modes require a special calibration
	       to determine the network delay between  the  local  and	remote
	       servers.	 Ordinarily, this is done automatically by the initial
	       protocol exchanges between  the	client	and  server.  In  some
	       cases,  the  calibration	 procedure  may fail due to network or
	       server access controls, for example. This command specifies the
	       default	delay  to be used under these circumstances. Typically
	       (for Ethernet), a number between 0.003  and  0.007  seconds  is
	       appropriate.

       driftfile driftfile { tolerance ]
	       This  command  specifies the complete path and name of the file
	       used to record the frequency of	the  local  clock  oscillator.
	       This  is	 the same operation as the -f command linke option. If
	       the file exists, it is read at startup in order to set the ini-
	       tial  frequency and then updated once per hour or more with the
	       current frequency computed by the daemon. If the file  name  is
	       specified,  but the file itself does not exist, the starts with
	       an initial frequency of zero and creates the file when  writing
	       it for the first time. If this command is not given, the daemon
	       will always start with an initial frequency of zero.  The  file
	       format  consists	 of a single line containing a single floating
	       point number, which records the frequency  offset  measured  in
	       parts-per-million  (PPM).  The file is updated by first writing
	       the current drift value into a temporary file and then renaming
	       this  file  to  replace the old version. This implies that ntpd
	       must have write permission for the directory the drift file  is
	       located	in, and that file system links, symbolic or otherwise,
	       should be avoided.   The	 parameter  tolerance  is  the	wander
	       threshold to skip writing the new value. If the value of wander
	       computed from recent frequency changes  is  greater  than  this
	       threshold  the file will be updated once per hour. If below the
	       threshold, the file will not be written.

       enable [ auth | bclient | calibrate | kernel | monitor | ntp  |	pps  |
       stats]

       disable	[  auth | bclient | calibrate | kernel | monitor | ntp | pps |
       stats ]
	       Provides a way to enable or  disable  various  system  options.
	       Flags  not  mentioned  are  unaffected.	Note that all of these
	       flags can be controlled remotely using the ntpdc	 utility  pro-
	       gram.

	       auth    Enables	the  server  to	 synchronize with unconfigured
		       peers only if the peer has been correctly authenticated
		       using  either  public  key or private key cryptography.
		       The default for this flag is enable.

	       bclient Enables the server to  listen  for  a  message  from  a
		       broadcast  or  multicast	 server,  as in the multicast-
		       client command with default address.  The  default  for
		       this flag is disable.

	       calibrate
		       Enables the calibrate feature for reference clocks. The
		       default for this flag is disable.

	       kernel  Enables the kernel time discipline, if  available.  The
		       default	for  this  flag is enable if support is avail-
		       able, otherwise disable.

	       monitor Enables the monitoring facility. See the ntpdc  program
		       and  the	 monlist  command  or further information. The
		       default for this flag is enable.

	       ntp     Enables time and frequency discipline. In effect,  this
		       switch  opens  and  closes  the feedback loop, which is
		       useful for  testing.  The  default  for	this  flag  is
		       enable.

	       stats   Enables	the  statistics	 facility.  See the Monitoring
		       Options page for further information. The  default  for
		       this flag is disable.


       includefile includefile
	       This  command  allows  additional  configuration commands to be
	       included from a separate file. Include files may be nested to a
	       depth  of five; upon reaching the end of any include file, com-
	       mand processing resumes in  the	previous  configuration	 file.
	       This  option  is	 useful	 for  sites  that run ntpd on multiple
	       hosts, with (mostly) common options (e.g., a restriction list).

       interface [listen | ignore | drop] [all | ipv4 | ipv6 | wildcard | name
       | address[/prefixlen]]
	       This  command  controls which network addresses ntpd opens, and
	       whether input is dropped without processing. The first  parame-
	       ter  determines the action for addresses which match the second
	       parameter. That parameter specifies a class of addresses, or  a
	       specific	 interface  name,  or an address. In the address case,
	       prefixlen determines how many bits must match for this rule  to
	       apply.  ignore prevents opening matching addresses, drop causes
	       ntpd to open the address and drop all received packets  without
	       examination.  Multiple interface commands can be used. The last
	       rule which matches a particular address determines  the	action
	       for it. interface commands are disabled if any -I, --interface,
	       -L, or --novirtualips command-line options are used. If none of
	       those  options  are used and no interface actions are specified
	       in the configuration file, all available network addresses  are
	       opened. The nic command is an alias for interface.

       leapfile leapfile
	       This  command  loads  the NIST leapseconds file and initializes
	       the leapsecond values for the next leapsecond time,  expiration
	       time  and  TAI  offset.	The file can be obtained directly from
	       NIST  national  time  servers  using  ftp  as  the  ASCII  file
	       pub/leap-seconds.   While not strictly a security function, the
	       Autokey protocol provides means to securely retrieve  the  cur-
	       rent or updated leapsecond values from a server.

       logconfig configkeyword
	       This  command controls the amount and type of output written to
	       the system syslog facility or the alternate logfile  log	 file.
	       All  configkeyword  keywords  can  be prefixed with =, + and -,
	       where = sets the syslogmask, + adds  and	 -  removes  messages.
	       syslog messages can be controlled in four classes (clock, peer,
	       sys and sync). Within these classes four types of messages  can
	       be  controlled:	informational  messages (info), event messages
	       (events), statistics messages (statistics) and status  messages
	       (status).   Configuration  keywords are formed by concatenating
	       the message class with the event class. The all prefix  can  be
	       used  instead  of  a message class. A message class may also be
	       followed by the all keyword to enable/disable all  messages  of
	       the  respective	message class. By default, logconfig output is
	       set to =syncall +sysevents +sysstatus.	Thus,  a  minimal  log
	       configuration  could  look  like	 this:	logconfig  =syncstatus
	       +sysevents This would just list the synchronizations  state  of
	       ntpd  and  the  major  system  events.  For  a simple reference
	       server, the following minimum message  configuration  could  be
	       useful:	logconfig  =syncall  +clockall This configuration will
	       list all clock information and synchronization information. All
	       other  events and messages about peers, system events and so on
	       is suppressed.

       logfile logfile
	       This command specifies the location of an alternate log file to
	       be  used instead of the default system syslog facility. This is
	       the same operation as the -l command line option.

       phone dial1 dial2 ...
	       This command is used in conjunction with the ACTS modem	driver
	       (type  18).  The arguments consist of a maximum of 10 telephone
	       numbers used to dial USNO, NIST or European time services.  The
	       Hayes  command  ATDT is normally prepended to the number, which
	       can contain other modem control codes as well.

       saveconfigdir directory_path
	       Specify the directory in which to write configuration snapshots
	       requested with ntpq's saveconfig command. If saveconfigdir does
	       not appear in the configuration file, saveconfig	 requests  are
	       rejected by ntpd.

       setvar variable [default]
	       This  command  adds  an additional system variable. These vari-
	       ables can be used to distribute additional information such  as
	       the  access policy. If the variable of the form name = value is
	       followed by the default keyword, the variable will be listed as
	       part  of	 the default system variables (ntpq rv command). These
	       additional variables serve informational	 purposes  only.  They
	       are  not related to the protocol other that they can be listed.
	       The known protocol variables will always override any variables
	       defined via the setvar mechanism. There are three special vari-
	       ables that contain the names of all variable of the same group.
	       The  sys_var_list  holds the names of all system variables. The
	       peer_var_list holds the names of all  peer  variables  and  the
	       clock_var_list  holds  the  names  of the reference clock vari-
	       ables.

       tinker [ allan allan | dispersion dispersion |  freq  freq  |  huffpuff
       huffpuff	 |  panic  panic  | step step | stepback step | stepfwd step |
       stepout stepout ]
	       This command alters certain system variables used by the	 clock
	       discipline  algorithm.  The  default  values of these variables
	       have been carefully optimized  for  a  wide  range  of  network
	       speeds  and  reliability expectations. Very rarely is it neces-
	       sary to change the default values; but, some folks can't resist
	       twisting the knobs. The options are as follows:


	       allan allan
		       Spedifies  the Allan intercept, which is a parameter of
		       the PLL/FLL clock discipline algorithm, in seconds with
		       default 1500 s.

	       dispersion dispersion
		       Specifies  the  dispersion  increase rate in parts-per-
		       million (PPM) with default 15 PPM.

	       freq freq
		       Spedifies the  frequency	 offset	 in  parts-per-million
		       (PPM) with default the value in the frequency file.

	       huffpuff huffpuff
		       Spedifies  the  huff-n'-puff  filter span, which deter-
		       mines the  most	recent	interval  the  algorithm  will
		       search  for  a  minimum delay. The lower limit is 900 s
		       (15 m), but a more reasonable value is 7200 (2 hours).

	       panic panic
		       Spedifies the panic threshold in seconds	 with  default
		       1000  s. If set to zero, the panic sanity check is dis-
		       abled and a clock offset of any value will be accepted.

	       step step
		       Spedifies the step threshold in	seconds.  The  default
		       without	this  command is 0.128 s. If set to zero, step
		       adjustments will never occur.  Note:  The  kernel  time
		       discipline  is disabled if the step threshold is set to
		       zero or greater than 0.5 s and the threshold is applied
		       also to leap second corrections.

	       stepback step
		       Specifies  the step threshold, but only in the backward
		       direction.

	       stepfwd step
		       Specifies the step threshold, but only in  the  forward
		       direction.  To avoid problems with frequency stabiliza-
		       tion after large slews it's not recommended to set  one
		       direction to a value greater than 0.5 s without setting
		       also the other direction to at least 0.5 s.

	       stepout stepout
		       Specifies the stepout threshold in seconds. The default
		       without	this command is 900 s. If set to zero, popcorn
		       spikes will not be suppressed.


       tos [ beacon beacon | ceiling ceiling | cohort {0 | 1} | floor floor  |
       maxclock	 maxclock  |  maxdist  maxdist	|  minclock minclock | mindist
       mindist | minsane minsane | orphan stratum ]
	       This command alters certain system variables used  by  the  the
	       clock  selection	 and clustering algorithms. The default values
	       of these variables have been carefully  optimized  for  a  wide
	       range  of  network  speeds  and	reliability expectations. Very
	       rarely is it necessary to change the default values; but,  some
	       folks can't resist twisting the knobs. It can be used to select
	       the quality and quantity of peers used to synchronize the  sys-
	       tem  clock  and	is  most  useful  in  dynamic server discovery
	       schemes. The options are as follows:


	       beacon beacon
		       The manycast server sends packets at intervals of 64  s
		       if less than maxclock servers are available. Otherwise,
		       it sends packets at the beacon interval in seconds. The
		       default	is  3600 s. See the Automatic Server Discovery
		       page for further details.

	       ceiling ceiling
		       Specify the maximum stratum (exclusive) for  acceptable
		       server  packets.	 The  default is 16. See the Automatic
		       Server Discovery page for further details.

	       cohort { 0 | 1 }
		       Specify whether (1) or whether not (0) a server	packet
		       will  be	 accepted  for the same stratum as the client.
		       The default is 0. See the  Automatic  Server  Discovery
		       page for further details.

	       floor floor
		       Specify	the minimum stratum (inclusive) for acceptable
		       server packest. The default is  1.  See	the  Automatic
		       Server Discovery page for further details.

	       maxclock maxclock
		       Specify	the  maximum number of servers retained by the
		       server discovery schemes. The default is	 10.  See  the
		       Automatic Server Discovery page for further details.

	       maxdist maxdistance
		       Specify	the synchronization distance threshold used by
		       the clock selection algorithm. The default  is  1.5  s.
		       This  determines	 both the minimum number of packets to
		       set the system clock and the maximum  roundtrip	delay.
		       It can be decreased to improve reliability or increased
		       to synchronize clocks on the Moon or planets.

	       minclock minclock
		       Specify the number of servers used  by  the  clustering
		       algorithm  as  the  minimum to include on the candidate
		       list. The default is 3. This  is	 also  the  number  of
		       servers to be averaged by the combining algorithm.

	       mindist mindistance
		       Specify	the minimum distance used by the selection and
		       anticlockhop algorithm. Larger values increase the tol-
		       erance for outliers; smaller values increase the selec-
		       tivity. The default is .001 s. In some cases,  such  as
		       reference  clocks with high jitter and a PPS signal, it
		       is useful to increase the value to insure the intersec-
		       tion interval is always nonempty.

	       minsane minsane
		       Specify	the  number  of	 servers used by the selection
		       algorithm as the minimum to set the system  clock.  The
		       default is 1 for legacy purposes; however, for critical
		       applications the value should be	 somewhat  higher  but
		       less than minclock.

	       orphan stratum
		       Specify	the  orphan  stratum  with default 16. If less
		       than 16	this  is  the  stratum	assumed	 by  the  root
		       servers.	 See  the Association Management page for fur-
		       ther details.


       trap host_address [port port_number] [interface interfSace_address]
	       This command configures a  trap	receiver  at  the  given  host
	       address and port number for sending messages with the specified
	       local interface address. If the port number is  unspecified,  a
	       value  of 18447 is used. If the interface address is not speci-
	       fied, the message is sent with a source address	of  the	 local
	       interface  the  message	is sent through. Note that on a multi-
	       homed host the interface used may vary from time to  time  with
	       routing	changes.   The	trap receiver will generally log event
	       messages and other information from the server in a  log	 file.
	       While  such  monitor  programs  may also request their own trap
	       dynamically, configuring a trap receiver will  ensure  that  no
	       messages are lost when the server is started.

       ttl hop ...
	       This  command  specifies	 a  list  of  TTL values in increasing
	       order. up to 8 values can be specified. In manycast mode	 these
	       values  are  used  in  turn  in	an  expanding-ring search. The
	       default is eight multiples of 32 starting at 31.

       dscp dscp
	       This command specifies the Differentiated Services  Code	 Point
	       (DSCP)  value  that  is	used  in sent NTP packets. The default
	       value is 48 for Class Selector 6 (CS6).


SEE ALSO
       ntp.conf(5)

       The official HTML documentation.

       This file was automatically generated from HTML source.




								   ntp_misc(5)