1NTP(8) System Manager's Manual NTP(8)
2
6 ntp - query an ntp clock
7
9 ntp [-v] [-s] [-f] hosts...
10
12 ntp sends an ntp packet to the ntp daemon running on each of the given
13 hosts. A daemon fills in fields of the ntp packet as per RFC-???? and
14 sends the packet back. ntp then formats and prints the result on the
15 standard output.
16 The default output shows the delay, offset, and date in ctime() format.
18 Options can reset the time of the local system clock.
20
22 -v Verbose output, showing the full contents of received ntp pack‐
23 ets, plus caluclated offset, displacement, etc.
24 -s Set system time-of-day clock. Will only happen if time offset
26 is less than compiled-in constant WAYTOBIG (currently 1000 sec‐
27 onds). Will not happen if remote host is unsynchronized.
28 -f Force setting system clock regardless of offset. Must be used
30 with -s option. Still will not reset clock if remote system is
31 unsynchronized.
32
34 The default output for each host looks like this:
35 128.8.10.1: delay:1.845207 offset:-0.358460 Mon Mar 20 08:05:44 1989
36 The verbose output for each host looks like this:
38 Packet from: [128.8.10.1]
39 Leap 0, version 1, mode Server, poll 6, precision -10 stratum 1 (WWVB)
40 Synch Distance is 0000.1999 0.099991
41 Synch Dispersion is 0000.0000 0.000000
42 Reference Timestamp is a7bea6c3.88b40000 Tue Mar 7 14:06:43 1989
43 Originate Timestamp is a7bea6d7.d7e6e652 Tue Mar 7 14:07:03 1989
44 Receive Timestamp is a7bea6d7.cf1a0000 Tue Mar 7 14:07:03 1989
45 Transmit Timestamp is a7bea6d8.0ccc0000 Tue Mar 7 14:07:04 1989
46 Input Timestamp is a7bea6d8.1a77e5ea Tue Mar 7 14:07:04 1989
47 umd1: delay:0.019028 offset:-0.043890 Tue Mar 7 14:07:04 1989
48 The various fields are interpreted as follows:
49 Packet from: [address]
51 The address that this ntp packet was received from.
52 Leap indicator: n
54 The leap second indicator. Non-zero if there is to be a leap
55 second added or subtracted at the new year.
56 Status: n
58 Stratum: n (source)
60 The stratum of the clock in the NTP hierarchy, along with the
61 source of the clock, either the name of a reference standard
62 (such as WWVB or GOES) or the Internet address of the clock that
63 this clock is derived from.
64 Poll = n
66 The desired poll rate of the peer.
67 Precision = exponent (dec)
69 The claimed precision of the clock, in seconds.
70 Synchronizing Dist is ???
72 Synchronizing Dispersion is ???
74 The next five timestamps are given as NTP fixed-point values, in both
76 hexadecimal and ctime(3). These are set either by this ntp process, or
77 by the server we are quering.
78 Reference Timestamp is hex-timestamp ctime string
80 The last time the server clock was adjusted. (remote time)
81 Originate Timestamp is hex-timestamp ctime string
83 When the ntp request was transmitted by us to the server.
84 (local time)
85 Receive Timestamp is hex-timestamp ctime string
87 When the ntp request was received at the server. (remote time)
88 Transmit Timestamp is hex-timestamp ctime string
90 When the ntp response was transmitted by the server. (remote
91 time)
92 Input Timestamp is hex-timestamp ctime string
94 When the ntp response was received by us. (local time)
95 hostname: delay:time offset:time
97 The summary of the results of the query, giving the hostname of
98 the responding clock (from the command line), the round-trip
99 delay, and the offset between the two clocks (assuming symmetric
100 round-trip times).
101
104 Using ntp with the current host will show inaccurate results.
105 Probably a few others. Report bugs to Louis A. Mamokos (louie@tran‐
107 tor.umd.edu).
108
111 RFC-???? Network Time Protocol(1), Dave Mills and ...
112 ntpd(8), ntpdc(8)
113 30 July 1988 NTP(8)