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SNTP(8)			      Programmer's Manual		       SNTP(8)



NAME
       sntp - standard Simple Network Time Protocol program

SYNOPSIS
       sntp [-flag [value]]... [--opt-name [[=| ]value]]...
	       [ hostname-or-IP ...]

DESCRIPTION
       This  manual page briefly documents the sntp command.  sntp can be used
       as a SNTP client to query a NTP or SNTP server and either  display  the
       time or set the local system's time (given suitable privilege).	It can
       be run as an interactive command or in a cron job.

       NTP (the Network Time Protocol) and SNTP (the Simple Network Time  Pro-
       tocol) are defined and described by RFC 5905.


       The default is to write the estimated correct local date and time (i.e.
       not  UTC)  to  the  standard  output  in	 a  format  like   '1996-10-15
       20:17:25.123  (+0800) +4.567 +/- 0.089 secs', where the '(+0800)' means
       that to get to UTC from the reported local time one must	 add  8	 hours
       and  0  minutes,	 and  the  '+4.567 +/- 0.089 secs' indicates the local
       clock is 4.567 seconds behind the correct time (so 4.567	 seconds  must
       be  added  to the local clock to get it to be correct), and the time of
       is believed to be correct to within +/- 0.089 seconds.

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 the 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 the following host names on the command
	      line to the IPv6 namespace.

       -d, --normalverbose
	      Normal verbose.

	      Diagnostic messages for non-fatal errors and a limited amount of
	      tracing  should be written to standard error.  Fatal ones always
	      produce a diagnostic.  This option should be set when there is a
	      suspected problem with the server, network or the source.

       -K file-name, --kod=file-name
	      KoD history filename.

	      Specifies	 the filename to be used to persist the history of KoD
	      responses	  received   from    servers.	  The	 default    is
	      /var/lib/ntp/sntp-kod.

       -p, --syslog
	      Logging with syslog.  This option must not appear in combination
	      with any of the following options: logfile.

	      When this option is set all logging will be done using syslog.

       -l file-name, --logfile=file-name
	      Log to specified logfile.	 This option must not appear in combi-
	      nation with any of the following options: syslog.

	      This option causes the client to write log messages to the spec-
	      ified logfile.

       -s, --settod
	      Set (step) the time with settimeofday().	This option  must  not
	      appear  in  combination  with any of the following options: adj-
	      time.



       -j, --adjtime
	      Set (slew) the time with adjtime().  This option must not appear
	      in combination with any of the following options: settod.



       -b broadcast-address, --broadcast=broadcast-address
	      Use broadcasts to the address specified for synchronisation.

	      If specified SNTP will listen to the specified broadcast address
	      for NTP broadcasts.  The default maximum wait time, 68  seconds,
	      can be modified with -t.

       -t seconds, --timeout=seconds
	      Specify  the  number  of	seconds	 to wait for broadcasts.  This
	      option takes an integer number as	 its  argument.	  The  default
	      seconds for this option is:
		   68

	      When waiting for a broadcast packet SNTP will wait the number of
	      seconds specified before giving up.  Default 68 seconds.

       -a auth-keynumber, --authentication=auth-keynumber
	      Enable authentication with the key auth-keynumber.  This	option
	      takes an integer number as its argument.

	      This  option  enables  authentication using the key specified in
	      this option's argument.  The argument  of	 this  option  is  the
	      keyid,  a	 number specified in the keyfile as this key's identi-
	      fier. See the keyfile option (-k) for more details.

       -k file-name, --keyfile=file-name
	      Specify a keyfile. SNTP will look in this file for the key spec-
	      ified with -a.

	      This  option specifies the keyfile. SNTP will search for the key
	      specified with -a keyno in this file. Key files follow the  fol-
	      lowing format:

	      keyid keytype key

	      Where	keyid  is a number identifying this key keytype is one
	      of the follow: S	Key in 64 Bit hexadecimal number as  specified
	      in  in the DES specification.  N	Key in 64 Bit hexadecimal num-
	      ber as specified in the NTP standard.  A	Key in a 1-to-8	 char-
	      acter  ASCII  string.  M	Key in a 1-to-8 character ASCII string
	      using the MD5 authentication scheme.

	      For more information see ntp.keys(5).

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

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

       -> [rcfile], --save-opts[=rcfile]
	      Save the option state to rcfile.	The default is the  last  con-
	      figuration file listed in the OPTION PRESETS section, below.

       -< rcfile, --load-opts=rcfile, --no-load-opts
	      Load  options  from  rcfile.  The no-load-opts form will disable
	      the loading of earlier RC/INI files.  --no-load-opts is  handled
	      early, out of order.

       - [{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 configuration ("RC" or ".INI") file(s) and values  from
       environment variables named:
	 SNTP_<option-name> or SNTP
       The  environmental  presets  take precedence (are processed later than)
       the configuration files.	 The homerc files are "$HOME",	and  ".".   If
       any  of	these  are  directories,  then the file .ntprc is searched for
       within those directories.

USAGE
       The simplest use of this program is as an unprivileged command to check
       the current time and error in the local clock.  For example:

	      sntp ntpserver.somewhere

       With suitable privilege, it can be run as a command or in a cron job to
       reset the local clock from a reliable  server,  like  the  ntpdate  and
       rdate commands.	For example:

	      sntp -a ntpserver.somewhere

RETURN VALUE
       The  program returns a zero exit status for success, and a non-zero one
       otherwise.

BUGS
       Please report bugs to http://bugs.ntp.org .

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 sntp option definitions.



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