1*2b15cb3dSCy Schubert<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 2*2b15cb3dSCy Schubert<html> 3*2b15cb3dSCy Schubert<head> 4*2b15cb3dSCy Schubert<meta http-equiv="content-type" content="text/html;charset=windows-1252"> 5*2b15cb3dSCy Schubert<meta name="generator" content="HTML Tidy, see www.w3.org"> 6*2b15cb3dSCy Schubert<title>Quick Start</title> 7*2b15cb3dSCy Schubert<link href="scripts/style.css" type="text/css" rel="stylesheet"> 8*2b15cb3dSCy Schubert</head> 9*2b15cb3dSCy Schubert<body> 10*2b15cb3dSCy Schubert<p>Last update: 11*2b15cb3dSCy Schubert <!-- #BeginDate format:En2m -->1-Dec-2012 04:44<!-- #EndDate --> 12*2b15cb3dSCy Schubert UTC</p> 13*2b15cb3dSCy Schubert<h3>Quick Start</h3> 14*2b15cb3dSCy Schubert<img src="pic/panda.gif" alt="gif" align="left">FAX test image for SATNET (1979). 15*2b15cb3dSCy Schubert<p>The baby panda was scanned at University College London and used as a FAX test image for a demonstration of the DARPA Atlantic SATNET Program and the first transatlantic Internet connection in 1978. The computing system used for that demonstration was called the <a href="http://www.eecis.udel.edu/%7emills/database/papers/fuzz.ps">Fuzzball</a>. As it happened, this was also the first Internet multimedia presentation and the first to use a predecessor of NTP in regular operation. The image was widely copied and used for testing purpose throughout much of the 1980s.</p> 16*2b15cb3dSCy Schubert<p>Last update: 17*2b15cb3dSCy Schubert <!-- #BeginDate format:En1m -->1-Dec-2012 04:44<!-- #EndDate --> 18*2b15cb3dSCy Schubert UTC</p> 19*2b15cb3dSCy Schubert<h4>Related Links</h4> 20*2b15cb3dSCy Schubert<script type="text/javascript" language="javascript" src="scripts/install.txt"></script> 21*2b15cb3dSCy Schubert<hr> 22*2b15cb3dSCy Schubert<p>For the rank amateur the sheer volume of the documentation collection must be intimidating. However, it doesn't take much to fly the <tt>ntpd</tt> daemon with a simple configuration where a workstation needs to synchronize to some server elsewhere in the Internet. The first thing is to build the distribution for the particular workstation and install in the usual place. The <a href="build.html">Building and Installing the Distribution</a> page describes how to do this.</p> 23*2b15cb3dSCy Schubert<p>While it is possible that certain configurations do not need a configuration file, most do. The file, called by default <tt>/etc/ntp.conf</tt>, need only contain one command specifying a remote server, for instance</p> 24*2b15cb3dSCy Schubert<p><tt>server foo.bar.com</tt></p> 25*2b15cb3dSCy Schubert<p>Choosing an appropriate remote server is somewhat of a black art, but a 26*2b15cb3dSCy Schubert suboptimal choice is seldom a problem. The simplest and best is to use the 27*2b15cb3dSCy Schubert Server Pool Scheme on the <a href="discover.html">Automatic Server Discovery</a> page. There 28*2b15cb3dSCy Schubert are about two dozen public time servers operated by the <a href="http://tf.nist.gov/tf-cgi/servers.cgi">National 29*2b15cb3dSCy Schubert Institutes of Science and Technology (NIST)</a>, <a href="http://tycho.usno.navy.mil/ntp.html">US 30*2b15cb3dSCy Schubert Naval Observatory (USNO)</a>, <a href="http://inms-ienm.nrc-cnrc.gc.ca/time_services/network_time_protocol_e.html"> Canadian 31*2b15cb3dSCy Schubert Metrology Centre (CMC)</a> and many others available on the Internet. Lists 32*2b15cb3dSCy Schubert of public primary and secondary NTP servers maintained on the <a href="http://support.ntp.org/Servers/WebHome">Public 33*2b15cb3dSCy Schubert NTP Time Servers</a> page, which is updated frequently. The lists are sorted 34*2b15cb3dSCy Schubert by country and, in the case of the US, by state. Usually, the best 35*2b15cb3dSCy Schubert choice is the nearest in geographical terms, but the terms of engagement 36*2b15cb3dSCy Schubert specified in each list entry should be carefully respected.</p> 37*2b15cb3dSCy Schubert<p>During operation <tt>ntpd</tt> measures and corrects for incidental clock frequency error and occasionally writes the current value to a file specified by the</p> 38*2b15cb3dSCy Schubert<p><tt>driftfile /etc/ntp.drift</tt></p> 39*2b15cb3dSCy Schubert<p>configuration command. If <tt>ntpd</tt> is stopped and restarted, it initializes the frequency from this file and avoids the potentially lengthy interval to relearn the correction.</p> 40*2b15cb3dSCy Schubert<p>That's all there is to it, unless some problem in network connectivity or local operating system configuration occurs. The most common problem is some firewall between the workstation and server. System administrators should understand NTP uses UDP port 123 as both the source and destination port and that NTP does not involve any operating system interaction other than to set the system clock. While almost all modern Unix systems have included NTP and UDP port 123 defined in the services file, this should be checked if <tt>ntpd</tt> fails to come up at all.</p> 41*2b15cb3dSCy Schubert<p>The best way to confirm NTP is working is using the <a href="ntpq.html"><tt>ntpq</tt></a> utility, although the <a href="ntpdc.html"><tt>ntpdc</tt></a> utility may be useful in extreme cases. See the documentation pages for further information. Don't forget to check for <a href="msyslog.html"> system log messages</a>. In the most extreme cases the <tt>-d</tt> option on the <tt>ntpd</tt> command line results in a blow-by-blow trace of the daemon operations. While the trace output can be cryptic, to say the least, it gives a general idea of what the program is doing and, in particular, details the arriving and departing packets and any errors found.</p> 42*2b15cb3dSCy Schubert<hr> 43*2b15cb3dSCy Schubert<script type="text/javascript" language="javascript" src="scripts/footer.txt"></script> 44*2b15cb3dSCy Schubert</body> 45*2b15cb3dSCy Schubert</html> 46
