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Commands Reference, Volume 4

ntptrace Command


Traces a chain of Network Time Protocol (NTP) hosts back to their master time source.


ntptrace [ -d ] [ -n ] [ -v ] [ -r Retries ] [ -t TimeOut ] [ Server ]


The ntptrace command determines where a given NTP server gets its time, and follows the chain of NTP servers back to their master time source. For example, stratum 0 server.


-d Turns on debugging output.
-n Outputs host IP addresses instead of host names.
-r Retries Specifies the number of retransmission attempts for each host. The default is 5.
-t TimeOut Specifies the retransmission timeout in seconds. The default is 2 seconds.
-v Specifies verbose mode.


Server Specifies the server. The default is the local host.

Exit Status

This command returns the following exit values:

0 Successful completion.
>0 An error occurred.


Access Control: You must be part of the system group to run this command.

Auditing Events: N/A


To trace where the local host NTP server gets its time from, enter:


Output similar to the following appears:

localhost: stratum 4, offset 0.0019529, synch distance 0.144135
server2.bozo.com: stratum 2, offset 0.0124263, synch distance 0.115784
usndh.edu: stratum 1, offset 0.0019298, synch distance 0.011993, refid

On each line, the fields are:

  1. the host's stratum,
  2. the time offset between that host and the local host, as measured by the ntptrace command, (this is why it is not always zero for localhost).
  3. the host's synchronization distance, which is a measure of the quality of the clock's time, and
  4. the reference clock ID This only applies to stratum-1 servers.

All times are given in seconds.


/usr/sbin/ntptrace Contains the ntptrace command.

Related Information

Commands: ntpq, ntpdate, xntpdc

Daemons: xntpd,

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