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SNTP(1)                              User                              SNTP(1)

NAME
     sntp -- standard Simple Network Time Protocol client program

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

DESCRIPTION
     sntp can be used as an 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 from a cron job.
     NTP (the Network Time Protocol) and SNTP (the Simple Network Time
     Protocol) 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 [host] IP sN' where the '(+0800)'
     means that to get to UTC from the reported local time one must add 8
     hours and 0 minutes, the '+4.567' 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).  Note that the number of decimals
     printed for this value will change based on the reported precision of the
     server.  '+/- 0.089' is the reported synchronization distance (in
     seconds), which represents the maximum error due to all causes.  If the
     server does not report valid data needed to calculate the synchronization
     distance, this will be reported as '+/- ?'.  If the host is different
     from the IP, both will be displayed.  Otherwise, only the IP is
     displayed.  Finally, the stratum of the host is reported.

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.

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

                 Enable 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.

     -b broadcast-address, --broadcast=broadcast-address
                 Listen to the address specified for broadcast time sync.
                 This option may appear an unlimited number of times.

                 If specified sntp will listen to the specified address for
                 NTP broadcasts.  The default maximum wait time can (and
                 probably should) be modified with -t.

     -c host-name, --concurrent=host-name
                 Concurrently query all IPs returned for host-name.  This
                 option may appear an unlimited number of times.

                 Requests from an NTP "client" to a "server" should never be
                 sent more rapidly than one every 2 seconds.  By default, any
                 IPs returned as part of a DNS lookup are assumed to be for a
                 single instance of ntpd, and therefore sntp will send queries
                 to these IPs one after another, with a 2-second gap in
                 between each query.

                 The -c or --concurrent flag says that any IPs returned for
                 the DNS lookup of the supplied host-name are on different
                 machines, so we can send concurrent queries.

     -d, --debug-level
                 Increase debug verbosity level.  This option may appear an
                 unlimited number of times.


     -D number, --set-debug-level=number
                 Set the debug verbosity level.  This option may appear an
                 unlimited number of times.  This option takes an integer
                 number as its argument.


     -g milliseconds, --gap=milliseconds
                 The gap (in milliseconds) between time requests.  This option
                 takes an integer number as its argument.  The default
                 milliseconds for this option is:
                  50

                 Since we're only going to use the first valid response we get
                 and there is benefit to specifying a good number of servers
                 to query, separate the queries we send out by the specified
                 number of milliseconds.

     -K file-name, --kod=file-name
                 KoD history filename.  The default file-name for this option
                 is:
                  /var/db/ntp-kod

                 Specifies the filename to be used for the persistent history
                 of KoD responses received from servers.

     -k file-name, --keyfile=file-name
                 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.  See ntp.keys(5)
                 for more information.

     -l file-name, --logfile=file-name
                 Log to specified logfile.

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

     -M number, --steplimit=number
                 Adjustments less than steplimit msec will be slewed.  This
                 option takes an integer number as its argument.  The value of
                 number is constrained to being: greater than or equal to 0

                 If the time adjustment is less than steplimit milliseconds,
                 slew the amount using adjtime(2).  Otherwise, step the
                 correction using settimeofday(2).

     -o number, --ntpversion=number
                 Send int as our NTP protocol version.  This option takes an
                 integer number as its argument.  The value of number is
                 constrained to being: in the range  0 through 7 The default
                 number for this option is:
                  4

                 When sending requests to a remote server, tell them we are
                 running NTP protocol version ntpversion .

     -r, --usereservedport
                 Use the NTP Reserved Port (port 123).

                 Use port 123, which is reserved for NTP, for our network
                 communications.

     -S, --step  OK to 'step' the time with settimeofday(2).


     -s, --slew  OK to 'slew' the time with adjtime(2).


     -t seconds, --timeout=seconds
                 The number of seconds to wait for responses.  This option
                 takes an integer number as its argument.  The default seconds
                 for this option is:
                  5

                 When waiting for a reply, sntp will wait the number of
                 seconds specified before giving up.  The default should be
                 more than enough for a unicast response.  If sntp is only
                 waiting for a broadcast response a longer timeout is likely
                 needed.

     --wait, - Fl -no-wait
                 Wait for pending replies (if not setting the time).  The
                 no-wait form will disable the option.  This option is enabled
                 by default.

                 If we are not setting the time, wait for all pending
                 responses.

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

     -!, --more-help
                 Pass the extended usage information through a pager.

     -> [cfgfile], --save-opts [=cfgfile]
                 Save the option state to cfgfile.  The default is the last
                 configuration file listed in the OPTION PRESETS section,
                 below.  The command will exit after updating the config file.

     -< cfgfile, --load-opts=cfgfile, --no-load-opts
                 Load options from cfgfile.  The no-load-opts form will
                 disable the loading of earlier config/rc/ini files.
                 --no-load-opts is handled early, out of order.

     --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
     "$HOME", and ".".  If any of these are directories, then the file .ntprc
     is searched for within those directories.
     cvt_prog='/usr/local/gnu/share/autogen/texi2mdoc' cvt_prog=`cd `dirname
     "$cvt_prog"` >/dev/null && pwd
              `/`basename "$cvt_prog"` cd $tmp_dir test -x "$cvt_prog" || die
     "'$cvt_prog' is not executable" {
         list='synopsis description options option-presets'
         for f in $list ; do cat $f ; echo ; done
         rm -f $list name
         list='implementation-notes environment files examples exit-status
     errors
             compatibility see-also conforming-to history authors copyright
     bugs
             notes'
         for f in $list ; do cat $f ; echo ; done > .end-doc
         rm -f $list
         list=`ls -1 *`' .end-doc'
         for f in $list ; do cat $f ; echo ; done
         rm -f $list } 1>.doc 2>/dev/null sed -f .cmds .doc |
     /usr/local/gnu/bin/grep -E -v '^[  ]*$' | $cvt_prog

USAGE
     sntp ntpserver.somewhere
             is the simplest use of this program and can be run as an
             unprivileged command to check the current time and error in the
             local clock.

     sntp -a ntpserver.somewhere
             With suitable privilege, run as a command or from a cron(8) job,
             sntp -a will reset the local clock from a synchronized specified
             server, like the (deprecated) ntpdate(8), or rdate(8) commands.

ENVIRONMENT
     See OPTION PRESETS for configuration environment variables.

FILES
     See OPTION PRESETS for configuration files.

EXIT STATUS
     One of the following exit values will be returned:

     0  (EXIT_SUCCESS)   Successful program execution.

     1  (EXIT_FAILURE)   The operation failed or the command syntax was not
                         valid.

     66  (EX_NOINPUT)    A specified configuration file could not be loaded.

     70  (EX_SOFTWARE)   libopts had an internal operational error.  Please
                         report it to autogen-users@lists.sourceforge.net.
                         Thank you.

AUTHORS
     Johannes Maximilian Kuehn
     Harlan Stenn
     Dave Hart

COPYRIGHT
     Copyright (C) 1970-2013 The University of Delaware all rights reserved.
     This program is released under the terms of the NTP license,
     <http://ntp.org/license>.

BUGS
     Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org

NOTES
     This document corresponds to version 4.2.7p404 of sntp.

     This manual page was AutoGen-erated from the sntp option definitions.

SunOS 5.10                     December 24 2013                     SunOS 5.10