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diff --git a/contrib/ntp/html/driver1.htm b/contrib/ntp/html/driver1.htm deleted file mode 100644 index b70010f..0000000 --- a/contrib/ntp/html/driver1.htm +++ /dev/null @@ -1,157 +0,0 @@ -<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 3.2//EN"> -<html> -<head> -<meta name="generator" content="HTML Tidy, see www.w3.org"> -<meta http-equiv="Content-Type" content= -"text/html; charset=iso-8859-1"> -<meta name="GENERATOR" content= -"Mozilla/4.01 [en] (Win95; I) [Netscape]"> -<title>Undisciplined Local Clock</title> -</head> -<body> -<h3>Undisciplined Local Clock</h3> - -<hr> -<h4>Synopsis</h4> - -Address: 127.127.1.<i>u</i> <br> -Reference ID: <tt>LCL</tt> <br> -Driver ID: <tt>LOCAL</tt> - -<h4>Description</h4> - -<p>This driver is intended for use in an isolated network where no -external source of synchronization such as a radio clock or modem -is available. It allows a designated time server to act as a -primary server to provide synchronization to other clients on the -network. Pick a machine that has a good clock oscillator (Digital -machines are good, Sun machines are not) and configure it with this -driver. Set the clock using the best means available, like -eyeball-and-wristwatch. Then, point all the other machines at this -one or use broadcast (not multicast) mode to distribute time.</p> - -<p>Another application for this driver is if a particular server -clock is to be used as the clock of last resort when all other -normal synchronization sources have gone away. This is especially -useful if that server has an ovenized oscillator. For this you -would configure this driver at a stratum greater than any other -likely sources of time (say 3 or 4) to prevent the server taking -over when legitimate sources are still available.</p> - -<p>A third application for this driver is when an external -discipline source is available, such as the NIST <tt>lockclock</tt> -program, which synchronizes the local clock via a telephone modem -and the NIST Automated Computer Time Service (ACTS), or the Digital -Time Synchronization Service (DTSS), which runs on DCE machines. In -this case the stratum should be set at zero, indicating a bona fide -stratum-1 source. In the case of DTSS, the local clock can have a -rather large jitter, depending on the interval between corrections -and the intrinsic frequency error of the clock oscillator. In -extreme cases, this can cause clients to exceed the 128-ms slew -window and drop off the NTP subnet.</p> - -<p>In the case where a NTP time server is synchronized to some -device or protocol that is not external to the NTP daemon itself, -some means should be provided to pass such things as error and -health values to the NTP daemon for dissemination to its clients. -If this is not done, there is a very real danger that the device or -protocol could fail and with no means to tell NTP clients of the -mishap. When ordinary Unix system calls like <tt>adjtime()</tt> are -used to discipline the kernel clock, there is no obvious way this -can be done without modifying the code for each case. However, when -a modified kernel with the <tt>ntp_adjtime()</tt> system call -is available, that routine can be used for the same purpose as the -<tt>adjtime()</tt> routine and in addition provided with the -estimated error, maximum error, and leap-indicator values. This is -the preferred way to synchronize the kernel clock and pass -information to the NTP clients.</p> - -<p>In the default mode the behavior of the clock selection -algorithm is modified when this driver is in use. The algorithm is -designed so that this driver will never be selected unless no other -discipline source is available. This can be overridden with the -<tt>prefer</tt> keyword of the <tt>server</tt> configuration -command, in which case only this driver will be selected for -synchronization and all other discipline sources will be ignored. -This behavior is intended for use when an external discipline -source controls the system clock. See the <a href="prefer.htm"> -Mitigation Rules and the <tt>prefer</tt> Keyword</a> page for a -detailed description of the exact behavior.</p> - -<p>The stratum for this driver is set at 3 by default, but can be -changed by the <tt>fudge</tt> configuration command and/or the <tt> -ntpdc</tt> utility. The reference ID is <tt>LCL</tt> by default, -but can be changed using the same mechanisms. <b>*NEVER*</b> -configure this driver to operate at a stratum which might possibly -disrupt a client with access to a bona fide primary server, unless -the local clock oscillator is reliably disciplined by another -source. <b>*NEVER NEVER*</b> configure a server which might devolve -to an undisciplined local clock to use multicast mode.</p> - -<p>This driver provides a mechanism to trim the local clock in both -time and frequency, as well as a way to manipulate the leap bits. -The <tt>fudge time1</tt> parameter adjusts the time (in seconds) -and the <tt>fudge time2</tt> parameter adjusts the frequency (in -parts per million). Both parameters are additive and operate only -once; that is, each command (as from <tt>ntpdc</tt>) adds signed -increments in time or frequency to the nominal local clock time and -frequency.</p> - -<h4>Monitor Data</h4> - -No <tt>filegen clockstats</tt> monitor data are produced by this -driver. - -<h4>Fudge Factors</h4> - -<dl> -<dt><tt>time1 <i>time</i></tt></dt> - -<dd>Specifies the time offset calibration factor, in seconds and -fraction, with default 0.0.</dd> - -<dt><tt>time2 <i>time</i></tt></dt> - -<dd>Specifies the frequency offset calibration factor, in parts per -million, with default 0.0.</dd> - -<dt><tt>stratum <i>number</i></tt></dt> - -<dd>Specifies the driver stratum, in decimal from 0 to 15, with -default 3.</dd> - -<dt><tt>refid <i>string</i></tt></dt> - -<dd>Specifies the driver reference identifier, an ASCII string from -one to four characters, with default <tt>LCL</tt>.</dd> - -<dt><tt>flag1 0 | 1</tt></dt> - -<dd>Not used by this driver.</dd> - -<dt><tt>flag2 0 | 1</tt></dt> - -<dd>Not used by this driver.</dd> - -<dt><tt>flag3 0 | 1</tt></dt> - -<dd>Not used by this driver.</dd> - -<dt><tt>flag4 0 | 1</tt></dt> - -<dd>Not used by this driver.</dd> -</dl> - -<p>Additional Information</p> - -<p><a href="refclock.htm">Reference Clock Drivers</a></p> - -<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 -<mills@udel.edu></a></address> -</body> -</html> - |
