NTP(8) NTP(8)
NAME
ntp - query an ntp clock
SYNOPSIS
ntp [-v] [-s] [-f] hosts...
DESCRIPTION
ntp sends an ntp packet to the ntp daemon running on each
of the given hosts. A daemon fills in fields of the ntp
packet as per RFC-???? and sends the packet back. ntp
then formats and prints the result on the standard output.
The default output shows the delay, offset, and date in
ctime() format.
Options can reset the time of the local system clock.
OPTIONS
-v Verbose output, showing the full contents of
received ntp packets, plus caluclated offset, dis-
placement, etc.
-s Set system time-of-day clock. Will only happen if
time offset is less than compiled-in constant WAY-
TOBIG (currently 1000 seconds). Will not happen if
remote host is unsynchronized.
-f Force setting system clock regardless of offset.
Must be used with -s option. Still will not reset
clock if remote system is unsynchronized.
NTP RESULTS
The default output for each host looks like this:
128.8.10.1: delay:1.845207 offset:-0.358460 Mon Mar 20 08:05:44 1989
The verbose output for each host looks like this:
Packet from: [128.8.10.1]
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
umd1: delay:0.019028 offset:-0.043890 Tue Mar 7 14:07:04 1989
The various fields are interpreted as follows:
Packet from: [address]
The address that this ntp packet was received from.
Leap indicator: n
The leap second indicator. Non-zero if there is to
be a leap second added or subtracted at the new
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NTP(8) NTP(8)
year.
Status: n
Stratum: n (source)
The stratum of the clock in the NTP hierarchy,
along with the source of the clock, either the name
of a reference standard (such as WWVB or GOES) or
the Internet address of the clock that this clock
is derived from.
Poll = n
The desired poll rate of the peer.
Precision = exponent (dec)
The claimed precision of the clock, in seconds.
Synchronizing Dist is ???
Synchronizing Dispersion is ???
The next five timestamps are given as NTP fixed-point val-
ues, in both hexadecimal and ctime(3). These are set
either by this ntp process, or by the server we are quer-
ing.
Reference Timestamp is hex-timestamp ctime string
The last time the server clock was adjusted.
(remote time)
Originate Timestamp is hex-timestamp ctime string
When the ntp request was transmitted by us to the
server. (local time)
Receive Timestamp is hex-timestamp ctime string
When the ntp request was received at the server.
(remote time)
Transmit Timestamp is hex-timestamp ctime string
When the ntp response was transmitted by the
server. (remote time)
Input Timestamp is hex-timestamp ctime string
When the ntp response was received by us. (local
time)
hostname: delay:time offset:time
The summary of the results of the query, giving the
hostname of the responding clock (from the command
line), the round-trip delay, and the offset between
the two clocks (assuming symmetric round-trip
times).
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NTP(8) NTP(8)
BUGS
Using ntp with the current host will show inaccurate
results.
Probably a few others. Report bugs to Louis A. Mamokos
(louie@trantor.umd.edu).
SEE ALSO
RFC-???? Network Time Protocol(1), Dave Mills and ...
ntpd(8), ntpdc(8)
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