19c2daa00SOllivier Robert<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 29c2daa00SOllivier Robert 39c2daa00SOllivier Robert<html> 49c2daa00SOllivier Robert 59c2daa00SOllivier Robert <head> 69c2daa00SOllivier Robert <meta name="generator" content="HTML Tidy, see www.w3.org"> 79c2daa00SOllivier Robert <title>ntptrace - trace a chain of NTP servers back to the primary source</title> 89c2daa00SOllivier Robert <link href="scripts/style.css" type="text/css" rel="stylesheet"> 99c2daa00SOllivier Robert </head> 109c2daa00SOllivier Robert 119c2daa00SOllivier Robert <body> 129c2daa00SOllivier Robert <h3><tt>ntptrace</tt> - trace a chain of NTP servers back to the primary source</h3> 139c2daa00SOllivier Robert <img src="pic/alice13.gif" alt="gif" align="left"><a href="http://www.eecis.udel.edu/~mills/pictures.html">from <i>Alice's Adventures in Wonderland</i>, Lewis Carroll</a> 149c2daa00SOllivier Robert <p>The rabbit knows the way back.</p> 159c2daa00SOllivier Robert <p>Last update: <csobj format="ShortTime" h="24" locale="00000409" region="0" t="DateTime" w="50">20:19</csobj> UTC <csobj format="LongDate" h="24" locale="00000409" region="0" t="DateTime" w="257">Monday, December 02, 2002</csobj></p> 169c2daa00SOllivier Robert <br clear="left"> 179c2daa00SOllivier Robert <hr> 189c2daa00SOllivier Robert <h4>Synopsis</h4> 199c2daa00SOllivier Robert <tt>ntptrace [ -vdn ] [ -r <i>retries</i> ] [ -t <i>timeout</i> ] [ <i>server</i> ]</tt> 209c2daa00SOllivier Robert <h4>Description</h4> 219c2daa00SOllivier Robert <p><tt>ntptrace</tt> determines where a given Network Time Protocol (NTP) server gets its time from, and follows the chain of NTP servers back to their master time source. If given no arguments, it starts with <tt>localhost</tt>. Here is an example of the output from <tt>ntptrace</tt>:</p> 229c2daa00SOllivier Robert <pre> 239c2daa00SOllivier Robert% ntptrace 249c2daa00SOllivier Robertlocalhost: stratum 4, offset 0.0019529, synch distance 0.144135 259c2daa00SOllivier Robertserver2ozo.com: stratum 2, offset 0.0124263, synch distance 0.115784 269c2daa00SOllivier Robertusndh.edu: stratum 1, offset 0.0019298, synch distance 0.011993, refid 'WWVB' 279c2daa00SOllivier Robert</pre> 289c2daa00SOllivier Robert <p>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 <tt>ntptrace</tt>; this is why it is not always zero for "<tt>localhost</tt>"), 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.</p> 299c2daa00SOllivier Robert <h4>Options</h4> 309c2daa00SOllivier Robert <dl> 319c2daa00SOllivier Robert <dt><tt>-d</tt> 329c2daa00SOllivier Robert <dd>Turns on some debugging output. 339c2daa00SOllivier Robert <dt><tt>-n</tt> 349c2daa00SOllivier Robert <dd>Turns off the printing of host names; instead, host IP addresses are given. This may be useful if a nameserver is down. 359c2daa00SOllivier Robert <dt><tt>-r <i>retries</i></tt> 369c2daa00SOllivier Robert <dd>Sets the number of retransmission attempts for each host (default = 5). 379c2daa00SOllivier Robert <dt><tt>-t <i>timeout</i></tt> 389c2daa00SOllivier Robert <dd>Sets the retransmission timeout (in seconds) (default = 2). 399c2daa00SOllivier Robert <dt><tt>-v</tt> 409c2daa00SOllivier Robert <dd>Prints verbose information about the NTP servers. 419c2daa00SOllivier Robert </dl> 429c2daa00SOllivier Robert <h4>Bugs</h4> 439c2daa00SOllivier Robert <p>This program makes no attempt to improve accuracy by doing multiple samples.</p> 449c2daa00SOllivier Robert <hr> 459c2daa00SOllivier Robert <script type="text/javascript" language="javascript" src="scripts/footer.txt"></script> 469c2daa00SOllivier Robert </body> 479c2daa00SOllivier Robert 489c2daa00SOllivier Robert</html>
