70 lines
2.2 KiB
HTML
70 lines
2.2 KiB
HTML
<!-- $NetBSD: ntptrace.html,v 1.1 1998/12/30 20:20:36 mcr Exp $ -->
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<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML Strict//EN">
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<html><head><title>
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ntptrace - trace a chain of NTP servers back to the primary
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source
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</title></head><body><h3>
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<code>ntptrace</code> - trace a chain of NTP servers back to the primary
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source
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</h3><hr>
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<p><h4>Synopsis</h4>
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<p><code>ntptrace [ -vdn ] [ -r <i>retries</i> ] [ -t <i>timeout</i> ] [
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<i>server</i> ]</code>
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<p><h4>Description</h4>
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<p><code>ntptrace</code> determines where a given Network Time Protocol
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(NTP) server gets its time from, and follows the chain of NTP servers
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back to their master time source. If given no arguments, it starts with
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<code>localhost</code>. Here is an example of the output from
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<code>ntptrace</code>:
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<pre>
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% ntptrace
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localhost: stratum 4, offset 0.0019529, synch distance 0.144135
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server2ozo.com: stratum 2, offset 0.0124263, synch distance 0.115784
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usndh.edu: stratum 1, offset 0.0019298, synch distance 0.011993, refid
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'WWVB'
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</pre>
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<p>On each line, the fields are (left to right): the host name, the host
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stratum, the time offset between that host and the local host (as
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measured by <code>ntptrace</code>; this is why it is not always zero for
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"<code>localhost</code>"), the host synchronization distance, and (only
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for stratum-1 servers) the reference clock ID. All times are given in
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seconds. Note that the stratum is the server hop count to the primary
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source, while the synchronization distance is the estimated error
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relative to the primary source. These terms are precisely defined in
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RFC-1305.
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<p><h4>Options</h4>
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<dl>
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<dt><code>-d</code>
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<dd>Turns on some debugging output.
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<p><dt><code>-n</code>
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<dd>Turns off the printing of host names; instead, host IP addresses are
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given. This may be useful if a nameserver is down.
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<p><dt><code>-r <i>retries</i></code>
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<dd>Sets the number of retransmission attempts for each host (default =
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5).
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<p><dt><code>-t <i>timeout</i></code>
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<dd>Sets the retransmission timeout (in seconds) (default = 2).
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<p><dt><code>-v</code>
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<dd>Prints verbose information about the NTP servers.
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</dl>
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<p><h4>Bugs</h4>
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<p>This program makes no attempt to improve accuracy by doing multiple
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samples.
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<hr><address>David L. Mills (mills@udel.edu)</address></body></html>
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