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SNTP(1)                 General Commands Manual (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