summaryrefslogtreecommitdiffstats
path: root/html/miscopt.htm
diff options
context:
space:
mode:
authorroberto <roberto@FreeBSD.org>2008-08-17 17:37:33 +0000
committerroberto <roberto@FreeBSD.org>2008-08-17 17:37:33 +0000
commit4ded1c1fa0bc21c61f91a2dbe864835986745121 (patch)
tree16d100fbc9dae63888d48b464e471ba0e5065193 /html/miscopt.htm
parent8b5a86d4fda08a9c68231415812edcb26be52f79 (diff)
downloadFreeBSD-src-4ded1c1fa0bc21c61f91a2dbe864835986745121.zip
FreeBSD-src-4ded1c1fa0bc21c61f91a2dbe864835986745121.tar.gz
Flatten the dist and various 4.n.n trees in preparation of future ntp imports.
Diffstat (limited to 'html/miscopt.htm')
-rw-r--r--html/miscopt.htm279
1 files changed, 279 insertions, 0 deletions
diff --git a/html/miscopt.htm b/html/miscopt.htm
new file mode 100644
index 0000000..348bc3e
--- /dev/null
+++ b/html/miscopt.htm
@@ -0,0 +1,279 @@
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
+<html>
+<head>
+<meta name="generator" content="HTML Tidy, see www.w3.org">
+<title>Miscellaneous Options</title>
+</head>
+<body>
+<h3>Miscellaneous Options</h3>
+
+<img align="left" src="pic/boom3.gif" alt="gif"><a href=
+"http://www.eecis.udel.edu/~mills/pictures.htm">from <i>Pogo</i>,
+Walt Kelly</a>
+
+<p>We have three, now looking for more.<br clear="left">
+</p>
+
+<hr>
+<dl>
+<dt><tt>broadcastdelay <i>seconds</i></tt></dt>
+
+<dd>The broadcast and multicast modes require a special calibration
+to determine the network delay between the local and remote
+servers. Ordinarily, this is done automatically by the initial
+protocol exchanges between the client and server. In some cases,
+the calibration procedure may fail due to network or server access
+controls, for example. This command specifies the default delay to
+be used under these circumstances. Typically (for Ethernet), a
+number between 0.003 and 0.007 seconds is appropriate. The default
+when this command is not used is 0.004 seconds.</dd>
+
+<dt><tt>driftfile <i>driftfile</i></tt></dt>
+
+<dd>This command specifies the name of the file used to record the
+frequency offset of the local clock oscillator. If the file exists,
+it is read at startup in order to set the initial frequency offset
+and then updated once per hour with the current frequency offset
+computed by the daemon. If the file does not exist or this command
+is not given, the initial frequency offset is assumed zero. In this
+case, it may take some hours for the frequency to stabilize and the
+residual timing errors to subside.
+
+<p>The file format consists of a single line containing a single
+floating point number, which records the frequency offset measured
+in parts-per-million (PPM). The file is updated by first writing
+the current drift value into a temporary file and then renaming
+this file to replace the old version. This implies that <tt>
+ntpd</tt> must have write permission for the directory the drift
+file is located in, and that file system links, symbolic or
+otherwise, should be avoided.</p>
+</dd>
+
+<dt><tt>enable [auth | bclient | calibrate | kernel | monitor | ntp
+| stats]</tt><br>
+<tt>disable [auth | bclient | calibrate | kernel | monitor | ntp |
+stats</tt></dt>
+
+<dd>Provides a way to enable or disable various server options.
+Flags not mentioned are unaffected. Note that all of these flags
+can be controlled remotely using the <a href="ntpdc.htm"><tt>
+ntpdc</tt></a> utility program.</dd>
+
+<dd>
+<dl>
+<dt><tt>bclient</tt></dt>
+
+<dd>When enabled, this is identical to the <tt>broadcastclient</tt>
+command. The default for this flag is <tt>disable</tt>.</dd>
+
+<dt><tt>calibrate</tt></dt>
+
+<dd>Enables the calibration facility, which automatically adjusts
+the <tt>time1</tt> values for each clock driver to display the same
+offset as the currently selected source or kernel discipline
+signal. See the <a href="refclock.htm">Reference Clock Drivers</a>
+for further information. The default for this flag is <tt>
+disable</tt>.</dd>
+
+<dt><tt>kernel</tt></dt>
+
+<dd>Enables the precision-time kernel support for the <tt>
+ntp_adjtime()</tt> system call, if implemented. Ordinarily, support
+for this routine is detected automatically when the NTP daemon is
+compiled, so it is not necessary for the user to worry about this
+flag. It flag is provided primarily so that this support can be
+disabled during kernel development. The default for this flag is
+<tt>enable</tt>.</dd>
+
+<dt><tt>monitor</tt></dt>
+
+<dd>Enables the monitoring facility. See the <tt>ntpdc</tt> program
+and the <tt>monlist</tt> command or further information. The
+default for this flag is <tt>enable</tt>.</dd>
+
+<dt><tt>ntp</tt></dt>
+
+<dd>Enables the server to adjust its local clock by means of NTP.
+If disabled, the local clock free-runs at its intrinsic time and
+frequency offset. This flag is useful in case the local clock is
+controlled by some other device or protocol and NTP is used only to
+provide synchronization to other clients. In this case, the local
+clock driver can be used to provide this function and also certain
+time variables for error estimates and leap-indicators. See the <a
+href="refclock.htm">Reference Clock Drivers</a> page for further
+information. The default for this flag is <tt>enable</tt>.</dd>
+
+<dt><tt>stats</tt></dt>
+
+<dd>Enables the statistics facility. See the <a href="monopt.htm">
+Monitoring Options</a> page for further information. The default
+for this flag is <tt>enable</tt>.</dd>
+</dl>
+</dd>
+
+<dt><tt>logconfig <i>configkeyword</i></tt></dt>
+
+<dd>This command controls the amount and type of output written to
+the system <tt>syslog</tt> facility or the alternate <tt>
+logfile</tt> log file. By default, all output is turned on. All <i>
+<tt>configkeyword</tt></i> keywords can be prefixed with <tt>
+=</tt>, <tt>+</tt> and <tt>-</tt>, where <tt>=</tt> sets the <tt>
+syslogmask</tt>, <tt>+</tt> adds and <tt>-</tt> removes messages.
+<tt>syslog messages</tt> can be controlled in four classes
+(<tt>clock</tt>, <tt>peer</tt>, <tt>sys</tt> and <tt>sync</tt>).
+Within these classes four types of messages can be controlled.</dd>
+
+<dd>Informational messages (<tt>info</tt>) control configuration
+information. Event messages (<tt>events</tt>) control logging of
+events (reachability, synchronization, alarm conditions).
+Statistical output is controlled with the <tt>statistics</tt>
+keyword. The final message group is the status messages. This
+describes mainly the synchronizations status. Configuration
+keywords are formed by concatenating the message class with the
+event class. The <tt>all</tt> prefix can be used instead of a
+message class. A message class may also be followed by the <tt>
+all</tt> keyword to enable/disable all messages of the respective
+message class.</dd>
+
+<dd>Thus, a minimal log configuration could look like this:
+
+<p><tt>logconfig=syncstatus +sysevents</tt></p>
+
+<p>This would just list the synchronizations state of <tt>ntpd</tt>
+and the major system events. For a simple reference server, the
+following minimum message configuration could be useful:</p>
+
+<p><tt>logconfig=syncall +clockall</tt></p>
+
+<p>This configuration will list all clock information and
+synchronization information. All other events and messages about
+peers, system events and so on is suppressed.</p>
+</dd>
+
+<dt><tt>logfile <i>logfile</i></tt></dt>
+
+<dd>This command specifies the location of an alternate log file to
+be used instead of the default system <tt>syslog</tt>
+facility.</dd>
+
+<dt><tt>setvar <i>variable</i> [default]</tt></dt>
+
+<dd>This command adds an additional system variable. These
+variables can be used to distribute additional information such as
+the access policy. If the variable of the form <tt><i>name</i> =
+<i>value</i></tt> is followed by the <tt>default</tt> keyword, the
+variable will be listed as part of the default system variables
+(<tt>ntpq rv</tt> command). These additional variables serve
+informational purposes only. They are not related to the protocol
+other that they can be listed. The known protocol variables will
+always override any variables defined via the <tt>setvar</tt>
+mechanism. There are three special variables that contain the names
+of all variable of the same group. The <tt>sys_var_list</tt> holds
+the names of all system variables. The <tt>peer_var_list</tt> holds
+the names of all peer variables and the <tt>clock_var_list</tt>
+holds the names of the reference clock variables.</dd>
+
+<dt><tt>tinker [ step <i>step</i> | panic <i>panic</i> | dispersion
+<i>dispersion</i> | stepout <i>stepout</i> | minpoll <i>minpoll</i>
+]</tt></dt>
+
+<dd>This command can be used to alter several system variables in
+very exceptional circumstances. It should occur in the
+configuration file before any other configuration options. The
+default values of these variables have been carefully optimized for
+a wide range of network speeds and reliability expectations. In
+general, they interact in intricate ways that are hard to predict
+and some combinations can result in some very nasty behavior. Very
+rarely is it necessary to change the default values; but, some
+folks can't resist twisting the knobs anyway and this command is
+for them. Emphasis added: twisters are on their own and can expect
+no help from the support group.
+
+<p>All arguments are in floating point seconds or seconds per
+second. The <tt>minpoll</tt> argument is an integer in seconds to
+the power of two. The variables operate as follows:</p>
+</dd>
+
+<dd>
+<dl>
+<dt><tt>step <i>step</i></tt></dt>
+
+<dd>The argument becomes the new value for the step threshold,
+normally 0.128 s. If set to zero, step adjustments will never
+occur. In general, if the intent is only to avoid step adjustments,
+the step threshold should be left alone and the <tt>-x</tt> command
+line option be used instead.</dd>
+
+<dt><tt>panic <i>panic</i></tt></dt>
+
+<dd>The argument becomes the new value for the panic threshold,
+normally 1000 s. If set to zero, the panic sanity check is disabled
+and a clock offset of any value will be accepted.</dd>
+
+<dt><tt>dispersion <i>dispersion</i></tt></dt>
+
+<dd>The argument becomes the new value for the dispersion increase
+rate, normally .000015.</dd>
+
+<dt><tt>stepout <i>stepout</i></tt></dt>
+
+<dd>The argument becomes the new value for the watchdog timeout,
+normally 900 s.</dd>
+
+<dt><tt>minpoll <i>minpoll</i></tt></dt>
+
+<dd>The argument becomes the new value for the minimum poll
+interval used when configuring multicast client, manycast client
+and , symmetric passive mode association. The value defaults to 6
+(64 s) and has a lower limit of 4 (16 s).</dd>
+
+<dt><tt>allan <i>allan</i></tt></dt>
+
+<dd>The argument becomes the new value for the minimum Allan
+intercept, which is a parameter of the PLL/FLL clock discipline
+algorithm. The value defaults to 1024 s, which is also the lower
+limit.</dd>
+
+<dt><tt>huffpuff <i>huffpuff</i></tt></dt>
+
+<dd>The argument becomes the new value for the experimental
+huff-n'-puff filter span, which determines the most recent interval
+the algorithm will search for a minimum delay. The lower limit is
+900 s (15 m), but a more reasonable value is 7200 (2 hours). There
+is no default, since the filter is not enabled unless this command
+is given.</dd>
+</dl>
+</dd>
+
+<dt><tt>trap <i>host_address</i> [port <i>port_number</i>]
+[interface <i>interface_address</i>]</tt></dt>
+
+<dd>This command configures a trap receiver at the given host
+address and port number for sending messages with the specified
+local interface address. If the port number is unspecified, a value
+of 18447 is used. If the interface address is not specified, the
+message is sent with a source address of the local interface the
+message is sent through. Note that on a multihomed host the
+interface used may vary from time to time with routing changes.
+
+<p>The trap receiver will generally log event messages and other
+information from the server in a log file. While such monitor
+programs may also request their own trap dynamically, configuring a
+trap receiver will ensure that no messages are lost when the server
+is started.</p>
+</dd>
+</dl>
+
+<h4>Files</h4>
+
+<tt>ntp.drift</tt> frequency compensation (PPM)
+
+<hr>
+<a href="index.htm"><img align="left" src="pic/home.gif" alt=
+"gif"></a>
+
+<address><a href="mailto:mills@udel.edu">David L. Mills
+&lt;mills@udel.edu&gt;</a></address>
+</body>
+</html>
+
OpenPOWER on IntegriCloud