1
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
4
<meta name="generator" content="HTML Tidy, see www.w3.org">
5
<title>Quick Start</title>
10
<img align="left" src="pic/panda.gif" alt="gif">FAX test image for
13
<p>The baby panda was scanned at University College London and used
14
as a FAX test image for a demonstration of the DARPA Atlantic
15
SATNET Program and the first transatlantic Internet connection in
16
1978. The computing system used for that demonstration was called
18
"http://www.eecis.udel.edu/~mills/database/papers/fuzz.ps">
19
Fuzzball</a> . As it happened, this was also the first Internet
20
multimedia presentation and the first to use NTP in regular
21
operation. The image was widely copied and used for testing purpose
22
throughout much of the 1980s.<br clear="left">
26
<p>For the rank amateur the sheer volume of the documentation
27
collection must be intimidating. However, it doesn't take much to
28
fly the <tt>ntpd</tt> daemon with a simple configuration where a
29
workstation needs to synchronize to some server elsewhere in the
30
Internet. The first thing that needs to be done is to build the
31
distribution for the particular workstation and install in the
32
usual place. The <a href="build.htm">Building and Installing the
33
Distribution</a> page describes how to do this.</p>
35
<p>While it is possible that certain configurations do not need a
36
configuration file, most do require one. Strictly speaking, the
37
file need only contain one line specifying a remote server, for
40
<p><tt>server foo.bar.com</tt></p>
42
<p>Choosing an appropriate remote server is somewhat of a black
43
art, but a suboptimal choice is seldom a problem. Links to public
44
time servers operated by National Institutes of Science and
45
Technology (NIST), US Naval Observatory (USNO), Canadian Metrology
46
Centre (CMC) and many others are given in the home page of this
47
document collection. The lists are sorted by country and, in the
48
case of the US, by state. Usually, the best choice is the nearest
49
in geographical terms, but the terms of engagement specified in
50
each list entry should be carefully respected.</p>
52
<p>During operation <tt>ntpd</tt> measures and corrects for
53
incidental clock frequency error and writes the current value to a
54
file if enabled. If the <tt>ntpd</tt> is stopped and restarted, it
55
initializes the frequency from this file. In this way the
56
potentially lengthy interval to relearn the frequency error is
57
avoided. Thus, for most applications an additional line should be
58
added to the file of the form</p>
60
<p><tt>driftfile /etc/ntp.drift</tt></p>
62
<p>That's all there is to it, unless some problem in network
63
connectivity or local operating system configuration occurs. The
64
most common problem is some firewall between the workstation and
65
server. System administrators should understand NTP uses UDP port
66
123 as both the source and destination port and that NTP does not
67
involve any operating system interaction other than to set the
68
system clock. While almost all modern Unix systems have included
69
NTP and UDP port 123 defined in the services file, this should be
70
checked if <tt>ntpd</tt> fails to come up at all.</p>
72
<p>The best way to confirm NTP is working is using the <a href=
73
"ntpq.htm"><tt>ntpq</tt></a> utility, although the <a href=
74
"ntpdc.htm"><tt>ntpdc</tt></a> utility may be useful in extreme
75
cases. See the documentation pages for further information. In the
76
most extreme cases the <tt>-d</tt> option on the <tt>ntpd</tt>
77
command line results in a blow-by-blow trace of the daemon
78
operations. While the trace output can be cryptic, to say the
79
least, it gives a general idea of what the program is doing and, in
80
particular, details the arriving and departing packets and detected
81
errors, if present.</p>
83
<p>Sometimes the <tt>ntpd</tt>. behavior may seem to violate the
84
Principle of Least Astonishment, but there are good reasons for
85
this. See the <a href="ntpd.htm">Network Time Protocol (NTP)
86
daemon</a> page for revealing insights. See this page and its
87
dependencies for additional configuration and control options. The
88
<a href="notes.htm">Notes on Configuring NTP and Setting up a NTP
89
Subnet</a> page contains an extended discussion of these
93
<a href="index.htm"><img align="left" src="pic/home.gif" alt=
96
<address><a href="mailto:mills@udel.edu">David L. Mills
97
<mills@udel.edu></a></address>
added
removed
html/quick.htm
