ntp_misc(pdf.php) - phpMan

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)