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 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
       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 output 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 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 following 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 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
              identifier. 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.



( 4.2.6p2)                        2010-07-09                           SNTP(1)
