ntp man page on DigitalUNIX

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ntp(1)									ntp(1)

       ntp - query a clock running a Network Time Protocol daemon, either ntpd
       or xntpd

       /usr/bin/ntp [-v] [-s] [-f] host1  | IPaddress1 ...

       Specifies verbose output.  The output shows the full  contents  of  the
       received NTP packets, plus the calculated offset and delay.  Sets local
       clock to remote time.  This only happens	 if  the  offset  between  the
       local and remote time is less than 1000 seconds. The local clock is not
       reset if the remote host is unsynchronized.

	      If you specify more than one host name on the command line,  ntp
	      queries  each  host in order, waiting for each host to answer or
	      timeout before querying the next host.  The local clock  is  set
	      to the time of the first remote host that responds.  Forces set‐
	      ting local clock regardless of offset.  The -f  option  must  be
	      used with -s option.  The local clock is not reset if the remote
	      host is unsynchronized.

       The ntp command may be retired in a future release; use the  ntpdate(8)
       command instead.

       The ntp command is used to determine the offset between the local clock
       and a remote clock.  It can also be used to set the local  host's  time
       to  a  remote  host's time.  The ntp command sends an NTP packet to the
       NTP daemon running on each of the remote hosts specified on the command
       line.  The remote hosts must be running either the ntpd daemon or xntpd
       daemon. When the NTP daemon on the remote host receives the NTP packet,
       it fills in the fields (as specified in RFC 1129), and sends the packet
       back.  The ntp command then formats and prints the results on the stan‐
       dard output.


       You  can	 specify  hosts	 by either host name or Internet address.  The
       hosts that you specify must either exist in the /etc/hosts file, or  in
       the master hosts database, if the database is being served to your sys‐
       tem by BIND or Network Information Service (NIS).

       The default output shows the roundtrip delay of the NTP packet in  sec‐
       onds,  the  estimated  offset between the local time and remote time in
       seconds, and the date in ctime format. See the ctime(3) reference  page
       for more information.

       The -s and -f options can be used to reset the time of the local clock.

       Using the -s and -f options require that you be logged on as superuser.

       The  following error messages can be returned by NTP: May indicate that
       the NTP daemon is not running on the remote host.  The NTP command can‐
       not resolve the specified host name in the /etc/hosts file.  Check that
       the host exists in the /etc/hosts file, or that it exists in the master
       hosts  database, if the database is being served to your system by BIND
       or NIS.

       In the following examples, some output text lines may  be  broken.  The
       line  end  are  marked  with the backslash symbol (\) and the following
       line is indented. Such text may appear as a single line on your	termi‐
       nal.   The  following  is  the  default	output to an ntp query about a
       remote host with an internet  address  of  555.5.55.5:  #  /usr/bin/ntp
       555.5.55.5 555.5.55.5: delay:1.845207 offset:-0.358460 \
	Mon Aug 20 08:05:44 1991 The following is the verbose output to an ntp
       query about the same remote host: # /usr/bin/ntp -v 555.5.55.5

       Packet from: [555.5.55.5] Leap 0, version 1, mode Server, poll 6,  pre‐
       cision \
	-10  stratum 1 (WWVB) Synch Distance is 0000.1999  0.099991 Synch Dis‐
       persion is 0000.0000  0.000000 Reference Timestamp is a7bea6c3.88b40000
	Tue Aug 20 14:06:43 1991 Originate Timestamp is a7bea6d7.d7e6e652 \
	Tue Aug 20 14:07:03 1991 Receive Timestamp is	a7bea6d7.cf1a0000 \
	Tue Aug 20 14:07:03 1991 Transmit Timestamp is	a7bea6d8.0ccc0000 \
	Tue Aug 20 14:07:04 1991 Input Timestamp is	a7bea6d8.1a77e5ea \
	Tue Aug 20 14:07:04 1991 555.5.55.5: delay:0.019028 offset:-0.043890 \
	Tue Aug 20 14:07:04 1991

	      The fields are interpreted as follows: The address of the remote
	      host from which this NTP packet was received.  The  leap	second
	      indicator.  Non-zero if there is to be a leap second inserted in
	      the NTP timescale.  The bits are set before 23:59 on the day  of
	      insertion	 and  reset after 00:00 on the following day.  The NTP
	      protocol version.	 The NTP mode can be Server, Client, Symmetric
	      Passive,	Symmetric Active, or Broadcast.	 See RFC 1129 for more
	      information on NTP modes.	 The desired poll rate of the peer  in
	      seconds  as  a  power  of 2. For example, if poll is equal to 6,
	      that means that the poll rate is	one  message  exchanged	 every
	      2**6  seconds.  The precision of the remote host's clock in sec‐
	      onds as a power of 2. For example, if precision is equal to -10,
	      that  means  that	 the precision is 2**-10.  The NTP daemon sets
	      this automatically.  The stratum of the clock in the NTP hierar‐
	      chy,  along  with the source of the clock.  The source is either
	      the name of a reference standard (such as WWVB or GOES), or  the
	      Internet	address	 of the clock that this clock references.  The
	      values reported are used internally by the NTP daemon.  The val‐
	      ues reported are used internally by the NTP daemon.

	      The next five timestamps are given as NTP fixed-point values, in
	      both hexadecimal and ctime. The timestamps  are  set  either  by
	      this NTP process, or by the remote host you are querying.	 These
	      timestamps are used by the local host  to	 calculate  delay  and
	      offset  for this query.  This specifies the last time the remote
	      host clock was adjusted.	(remote time) This specifies when  the
	      NTP  request  was	 transmitted  by  the local host to the remote
	      host. (local time) This  specifies  when	the  NTP  request  was
	      received	at the remote host.  (remote time) This specifies when
	      the NTP response was transmitted by the  remote  host.   (remote
	      time)  This  specifies when the NTP response was received by the
	      local host. (local time) This field summarizes  the  results  of
	      the  query,  giving  the	host  name  or internet address of the
	      responding clock specified in the command line,  the  round-trip
	      delay  in seconds, and the offset between the two clocks in sec‐
	      onds (assuming symmetric round-trip times).

       ctime(3), ntp.conf(4), ntpdate(8), xntpd(8), xntpdc(8), ntpq(8)

       Internet time synchronization:  The Network Time Protocol (RFC 1129)

       Network Administration: Services


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