Invoking sntp
=============

This program has no explanation.

.I sntp implements the Simple Network Time Protocol, and is used to query an NTP or SNTP server and either display the time or set the local system's time (given suitable privilege).

It can be run interactively from the command line or as a .I cron job.

NTP and SNTP are defined by draft-ietf-ntp-ntpv4-proto-13, which obsoletes RFC 4330 and RFC 1305.

This section was generated by AutoGen, the aginfo template and the option descriptions for the sntp program.  It documents the sntp usage text and option meanings.

This software is released under a specialized copyright license.

sntp usage help (-?)
--------------------

This is the automatically generated usage text for sntp:

     sntp - standard SNTP program - Ver. 4.2.6
     USAGE:  sntp [ -<flag> [<val>] | --<name>[{=| }<val>] ]... hostname-or-IP ...
       Flg Arg Option-Name    Description
        -4 no  ipv4           Force IPv4 DNS name resolution
                                     - prohibits these options:
                                     ipv6
        -6 no  ipv6           Force IPv6 DNS name resolution
                                     - prohibits these options:
                                     ipv4
        -d no  normalverbose  Normal verbose
        -K Str kod            KoD history filename
        -p no  syslog         Logging with syslog
                                     - prohibits these options:
                                     filelog
        -l Str filelog        Log to specified logfile
                                     - prohibits these options:
                                     syslog
        -s no  settod         Set (step) the time with settimeofday()
                                     - prohibits these options:
                                     adjtime
        -j no  adjtime        Set (slew) the time with adjtime()
                                     - prohibits these options:
                                     settod
        -b Str broadcast      Use broadcasts to the address specified for synchronisation
        -t Num timeout        Specify the number of seconds to wait for broadcasts
        -a Num authentication Enable authentication with the key auth-keynumber
        -k Str keyfile        Specify a keyfile. SNTP will look in this file for the key specified with -a
           opt version        Output version information and exit
        -? no  help           Display extended usage information and exit
        -! no  more-help      Extended usage information passed thru pager
        -> opt save-opts      Save the option state to a config file
        -< Str load-opts      Load options from a config file
                                     - disabled as --no-load-opts
                                     - may appear multiple times

     Options are specified by doubled hyphens and their name
     or by a single hyphen and the flag character.

     The following option preset mechanisms are supported:
      - reading file /users/stenn/.ntprc
      - reading file /deacon/backroom/snaps/ntp-stable/sntp/.ntprc
      - examining environment variables named SNTP_*

     .I sntp
     implements the Simple Network Time Protocol, and is used
     to query an NTP or SNTP server and either
     display the time
     or
     set the local system's time (given suitable privilege).

     It can be
     run interactively from the command line or as a
     .I cron
     job.

     NTP and SNTP are defined by draft-ietf-ntp-ntpv4-proto-13, which
     obsoletes RFC 4330 and RFC 1305.

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

ipv4 option (-4)
----------------

This is the ``force ipv4 dns name resolution'' option.

This option has some usage constraints.  It:

  * 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.

ipv6 option (-6)
----------------

This is the ``force ipv6 dns name resolution'' option.

This option has some usage constraints.  It:

  * 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.

normalverbose option (-d)
-------------------------

This is the ``normal verbose'' option. 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.

kod option (-K)
---------------

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

syslog option (-p)
------------------

This is the ``logging with syslog'' option.

This option has some usage constraints.  It:

  * must not appear in combination with any of the following options: filelog.

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

filelog option (-l)
-------------------

This is the ``log to specified logfile'' option.

This option has some usage constraints.  It:

  * 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.

settod option (-s)
------------------

This is the ``set (step) the time with settimeofday()'' option.

This option has some usage constraints.  It:

  * must not appear in combination with any of the following options: adjtime.

adjtime option (-j)
-------------------

This is the ``set (slew) the time with adjtime()'' option.

This option has some usage constraints.  It:

  * must not appear in combination with any of the following options: settod.

broadcast option (-b)
---------------------

This is the ``use broadcasts to the address specified for synchronisation'' option. 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.

timeout option (-t)
-------------------

This is the ``specify the number of seconds to wait for broadcasts'' option. When waiting for a broadcast packet SNTP will wait the number of seconds specified before giving up.  Default 68 seconds.

authentication option (-a)
--------------------------

This is the ``enable authentication with the key auth-keynumber'' option. 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.

keyfile option (-k)
-------------------

This is the ``specify a keyfile. sntp will look in this file for the key specified with -a'' option. 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).