NTPTRACE(1) BSD General Commands Manual NTPTRACE(1)


ntptrace — Trace peers of an NTP server


ntptrace [-flags] [-flag [value]] [--option-name[

=| ]value ]] [host]


ntptrace is a perl script that uses the ntpq utility program to follow the chain of NTP servers from a given host back to the primary time source. For ntptrace to work properly, each of these servers must implement the NTP Control and Monitoring Protocol specified in RFC 1305 and enable NTP Mode 6 packets.

If given no arguments, ntptrace starts with localhost. Here is an example of the output from ntptrace:

% ntptrace localhost: stratum 4, offset 0.0019529, synch distance 0.144135
server2ozo.com: stratum 2, offset 0.0124263, synch distance 0.115784 usndh.edu:
stratum 1, offset 0.0019298, synch distance 0.011993, refid ’WWVB’

On each line, the fields are (left to right): the host name, the host stratum, the time offset between that host and the local host (as measured by ntptrace; this is why it is not always zero for "localhost"), the host synchronization distance, and (only for stratum-1 servers) the reference clock ID. All times are given in seconds. Note that the stratum is the server hop count to the primary source, while the synchronization distance is the estimated error relative to the primary source. These terms are precisely defined in RFC-1305.

, --numeric

Print IP addresses instead of hostnames.

Output hosts as dotted-quad numeric format rather than converting to the canonical host names.

-m number, --max-hosts=number

Maximum number of peers to trace. This option takes an integer number as its argument. The default number for this option is:

This option has not been fully documented.

-r string, --host=string

Single remote host. The default string for this option is:

This option has not been fully documented.

-?, --help

Display usage information and exit.

-!, --more-help

Pass the extended usage information through a pager.

-v [{v|c|n --version [{v|c|n}]}]

Output version of program and exit. The default mode is ’v’, a simple version. The ’c’ mode will print copyright information and ’n’ will print the full copyright notice.


One of the following exit values will be returned:


Successful program execution.


The operation failed or the command syntax was not valid.


libopts had an internal operational error. Please report it to autogen-users@lists.sourceforge.net. Thank you.


This manual page was AutoGen-erated from the ntptrace option definitions.

BSD March 21 2017 BSD