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



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  com-
       mand or in 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 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/lib/ntp/sntp-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, bugsATntp.org


       see html/copyright.html

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



( 4.2.6p3-RC10)                                            2010-11-14                                                    SNTP(8)