83 lines
2.2 KiB
HTML
83 lines
2.2 KiB
HTML
<HTML>
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<HEAD>
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<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1">
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<META NAME="GENERATOR" CONTENT="Mozilla/4.01 [en] (Win95; I) [Netscape]">
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<TITLE>ntptrace - trace a chain of NTP servers back to the primary
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source
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</TITLE>
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</HEAD>
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<BODY>
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<H3>
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<TT>ntptrace</TT> - trace a chain of NTP servers back to the primary source</H3>
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<HR>
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<H4>
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Synopsis</H4>
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<TT>ntptrace [ -vdn ] [ -r <I>retries</I> ] [ -t <I>timeout</I> ] [ <I>server</I>
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]</TT>
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<H4>
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Description</H4>
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<TT>ntptrace</TT> determines where a given Network Time Protocol (NTP)
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server gets its time from, and follows the chain of NTP servers back to
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their master time source. If given no arguments, it starts with <TT>localhost</TT>.
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Here is an example of the output from <TT>ntptrace</TT>:
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<PRE>% 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'</PRE>
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On each line, the fields are (left to right): the host name, the host stratum,
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the time offset between that host and the local host (as measured by <TT>ntptrace</TT>;
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this is why it is not always zero for "<TT>localhost</TT>"), the host synchronization
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distance, and (only for stratum-1 servers) the reference clock ID. All
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times are given in seconds. Note that the stratum is the server hop count
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to the primary source, while the synchronization distance is the estimated
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error relative to the primary source. These terms are precisely defined
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in RFC-1305.
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<H4>
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Options</H4>
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<DL>
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<DT>
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<TT>-d</TT></DT>
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<DD>
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Turns on some debugging output.</DD>
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<DT>
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<TT>-n</TT></DT>
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<DD>
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Turns off the printing of host names; instead, host IP addresses are given.
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This may be useful if a nameserver is down.</DD>
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<DT>
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<TT>-r <I>retries</I></TT></DT>
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<DD>
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Sets the number of retransmission attempts for each host (default = 5).</DD>
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<DT>
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<TT>-t <I>timeout</I></TT></DT>
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<DD>
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Sets the retransmission timeout (in seconds) (default = 2).</DD>
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<DT>
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<TT>-v</TT></DT>
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<DD>
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Prints verbose information about the NTP servers.</DD>
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</DL>
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<H4>
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Bugs</H4>
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This program makes no attempt to improve accuracy by doing multiple samples.
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<HR>
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<ADDRESS>
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David L. Mills (mills@udel.edu)</ADDRESS>
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</BODY>
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</HTML>
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