ntp(1)							      General Commands Manual							    ntp(1)

Name
       ntp - query a clock running the Network Time Protocol daemon, ntpd

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

Description
       The  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 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 When the 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 command then formats and prints the results on the standard output.  You can	specify  hosts	by
       either host name or Internet address.  The hosts that you specify must either exist in the file, or in the master database, if the database
       is being served to your system by BIND/Hesiod or Yellow Pages.  The default output shows the roundtrip delay of the NTP packet in  seconds,
       the  estimated  offset between the local time and remote time in seconds, and the date in format.  See the reference page for more informa-
       tion.

       The and options can be used to reset the time of the local clock.  Use with these options to initialize the system time	prior  to  running
       the daemon.

Options
       -v   Specifies verbose output.  The output shows the full contents of the received NTP packets, plus the calculated offset and delay.

       -s   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, 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.

       -f   Forces  setting  local  clock  regardless of offset.  The option must be used with option.	The local clock is not reset if the remote
	    host is unsynchronized.

Restrictions
       Using the and options require that you be logged on as superuser.

Examples
       The following is the default output to an query about a remote host with an internet address of 555.5.55.5:
       # /usr/etc/ntp 555.5.55.5

       555.5.55.5: delay:1.845207 offset:-0.358460  Mon Mar 20 08:05:44 1989

       The following is the verbose output to an query about the same remote host:
       # /usr/etc/ntp -v 555.5.55.5

       Packet from: [555.5.55.5]
       Leap 0, version 1, mode Server, poll 6, precision -10 stratum 1 (WWVB)
       Synch Distance is 0000.1999  0.099991
       Synch Dispersion is 0000.0000  0.000000
       Reference Timestamp is a7bea6c3.88b40000 Tue Mar  7 14:06:43 1989
       Originate Timestamp is a7bea6d7.d7e6e652 Tue Mar  7 14:07:03 1989
       Receive Timestamp is   a7bea6d7.cf1a0000 Tue Mar  7 14:07:03 1989
       Transmit Timestamp is  a7bea6d8.0ccc0000 Tue Mar  7 14:07:04 1989
       Input Timestamp is     a7bea6d8.1a77e5ea Tue Mar  7 14:07:04 1989
       555.5.55.5: delay:0.019028 offset:-0.043890  Tue Mar  7 14:07:04 1989

       The fields are interpreted as follows:

       Packet from: [internet address]
	    The address of the remote host from which this NTP packet was received.

       Leap n
	    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.

       version n
	    The NTP protocol version.

       mode type
	    The NTP mode can be Server, Client, Symmetric Passive, Symmetric Active, or Broadcast. See RFC 1129 for more information on NTP modes.

       Poll x
	    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.

       Precision x
	    The precision of the remote host's clock in seconds as a power of 2.  For example, if precision is equal to -10, that means  that  the
	    precision is 2**-10.  The daemon sets this automatically.

       Stratum n (source)
	    The stratum of the clock in the NTP hierarchy, along with the source of the clock.	The source is either the name of a reference stan-
	    dard (such as WWVB or GOES), or the Internet address of the clock that this clock references.

       Synch Distance is nn.nn nn.nn
	    The values reported are used internally by

       Synch Dispersion is nn.nn nn.nn
	    The values reported are used internally by

       The next five timestamps are given as NTP fixed-point values, in both hexadecimal and 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.

       Reference Timestamp is hex-timestamp ctime_string
	      This specifies the last time the remote host clock was adjusted.	(remote time)

       Originate Timestamp is hex-timestamp ctime_string
	      This specifies when the NTP request was transmitted by the local host to the remote host. (local time)

       Receive Timestamp is hex-timestamp ctime_string
	      This specifies when the NTP request was received at the remote host.  (remote time)

       Transmit Timestamp is hex-timestamp ctime_string
	      This specifies when the NTP response was transmitted by the remote host.	(remote time)

       Input Timestamp is hex-timestamp ctime_string
	    This specifies when the NTP response was received by the local host.  (local time)

       hostname: delay:time offset:time
	    This field summarizes the results of the query, giving the host name or internet address of the responding clock specified in the com-
	    mand line, the round-trip delay in seconds, and the offset between the two clocks in seconds (assuming symmetric round-trip times).

Diagnostics
       The following error messages can be returned by NTP:

       *Timeout*

       hostname is not responding
			   May indicate that the daemon is not running on the remote host.

       No such host: hostname
			   The daemon cannot resolve the specified host name in the file.  Check that the host exists in  the  file,  or  that	it
			   exists in the master database, if the database is being served to your system by BIND/Hesiod or Yellow Pages.

See Also
       ctime(3), ntp.conf(5), ntpd(8), ntpdc(8)
       RFC 1129--Internet time synchronization:  The Network Time Protocol
       Guide to System and Network Setup
       Introduction to Networking and Distributed System Services

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