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SNTP(1)                                      Programmer's Manual                                     SNTP(1)



NAME
       sntp - standard SNTP 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  privi-lege). privilege).
       lege).  It can be run as an interactive command or in a cron job.

       NTP (the Network Time Protocol) and SNTP (the Simple Network Time Protocol) are defined and described
       by draft-ietf-ntp-ntpv4-proto-13, which should become a full RFC any month now.


       The default is to write the estimated correct local date and time (i.e. not UTC) to the standard out-put output
       put  in  a  format like '1996 Oct 15 20:17:25.123 +4.567 +/- 0.089 secs', where 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 1996 Oct 15 20:17:25.123 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 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.

       -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.

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

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

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

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

              This option causes the client to write log messages to the specified logfile.

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



       -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 giv-ing giving
              ing 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. identifier.
              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 specified with -a.

              This  option  specifies  the  keyfile. SNTP will search for the key specified with -a keyno in
              this file. Key files follow the following 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
              number as specified in the NTP standard.  A  Key in a 1-to-8 character 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 configuration 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 loading 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.



( 4.2.6)                                         2009-12-10                                          SNTP(1)