19c2daa00SOllivier Robert<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 29c2daa00SOllivier Robert 39c2daa00SOllivier Robert<html> 49c2daa00SOllivier Robert 59c2daa00SOllivier Robert <head> 6ea906c41SOllivier Robert <meta http-equiv="content-type" content="text/html;charset=iso-8859-1"> 79c2daa00SOllivier Robert <title>Miscellaneous Options</title> 89c2daa00SOllivier Robert <link href="scripts/style.css" type="text/css" rel="stylesheet"> 99c2daa00SOllivier Robert </head> 109c2daa00SOllivier Robert 119c2daa00SOllivier Robert <body> 129c2daa00SOllivier Robert <h3>Miscellaneous Options</h3> 139c2daa00SOllivier Robert <img src="pic/boom3.gif" alt="gif" align="left"><a href="http://www.eecis.udel.edu/~mills/pictures.html">from <i>Pogo</i>, Walt Kelly</a> 149c2daa00SOllivier Robert <p>We have three, now looking for more.</p> 15ea906c41SOllivier Robert <p>Last update: <csobj format="ShortTime" h="25" locale="00000409" region="0" t="DateTime" w="61">18:50</csobj> UTC <csobj format="LongDate" h="25" locale="00000409" region="0" t="DateTime" w="271">Monday, January 09, 2006</csobj></p> 169c2daa00SOllivier Robert <br clear="left"> 179c2daa00SOllivier Robert <h4>Related Links</h4> 189c2daa00SOllivier Robert <script type="text/javascript" language="javascript" src="scripts/links7.txt"></script> 199c2daa00SOllivier Robert <hr> 209c2daa00SOllivier Robert <dl> 219c2daa00SOllivier Robert <dt><tt>broadcastdelay <i>seconds</i></tt> 229c2daa00SOllivier Robert <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. 239c2daa00SOllivier Robert <dt><tt>calldelay <i>delay</i></tt> 249c2daa00SOllivier Robert <dd>This option controls the delay in seconds between the first and second packets sent in burst or iburst mode to allow additional time for a modem or ISDN call to complete. 25ea906c41SOllivier Robert <dt><tt>driftfile <i>driftfile</i> [<i> 26ea906c41SOllivier Robert minutes </i> [<i> tolerance </i>] ]</tt> 279c2daa00SOllivier Robert <dd>This command specifies the complete path and name of the file used to record the frequency of the local clock oscillator. This is the same operation as the <tt>-f</tt> command linke option. If the file exists, it is read at startup in order to set the initial frequency and then updated once per hour with the current frequency computed by the daemon. If the file name is specified, but the file itself does not exist, the starts with an initial frequency of zero and creates the file when writing it for the first time. If this command is not given, the daemon will always start with an initial frequency of zero. 289c2daa00SOllivier Robert <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> 29ea906c41SOllivier Robert 30ea906c41SOllivier Robert<p>The two optional values determine how often the file is written, and 31ea906c41SOllivier Robertare particuarly useful when is it desirable to avoid spinning up the 32ea906c41SOllivier Robertdisk unnecessarily. The parameter <tt>minutes</tt> is how often the file will be written. If omitted or less 33ea906c41SOllivier Robertthan 1, the interval will be 60 minutes (one hour). The parameter <tt>tolerance</tt> is the 34ea906c41SOllivier Robertthreshold to skip writing the new value. If the new value is within 35ea906c41SOllivier Robert<tt>tolerance</tt> percent of the last value written (compared out to 3 36ea906c41SOllivier Robertdecimal places), the write will be 37ea906c41SOllivier Robertskipped. The default is 0.0, which means that the write will occur 38ea906c41SOllivier Robertunless the current and previous values are the same. A tolerance of 39ea906c41SOllivier Robert.1 equates roughly to a difference in the 2nd decimal place.</p> 409c2daa00SOllivier Robert<dt><tt>enable [ auth | bclient | calibrate | kernel | monitor | ntp | pps | stats]</tt><br> 419c2daa00SOllivier Robert <tt>disable [ auth | bclient | calibrate | kernel | monitor | ntp | pps | stats ]</tt> 429c2daa00SOllivier Robert <dd>Provides a way to enable or disable various system options. Flags not mentioned are unaffected. Note that all of these flags can be controlled remotely using the <a href="ntpdc.html"><tt>ntpdc</tt></a> utility program. 439c2daa00SOllivier Robert <dl> 449c2daa00SOllivier Robert <dt><tt>auth</tt> 459c2daa00SOllivier Robert <dd>Enables the server to synchronize with unconfigured peers only if the peer has been correctly authenticated using either public key or private key cryptography. The default for this flag is enable. 469c2daa00SOllivier Robert <dt><tt>bclient</tt> 479c2daa00SOllivier Robert <dd>Enables the server to listen for a message from a broadcast or multicast server, as in the <tt>multicastclient</tt> command with default address. The default for this flag is disable. 489c2daa00SOllivier Robert <dt><tt>calibrate</tt> 499c2daa00SOllivier Robert <dd>Enables the calibrate feature for reference clocks. The default for this flag is disable. 509c2daa00SOllivier Robert <dt><tt>kernel</tt> 519c2daa00SOllivier Robert <dd>Enables the kernel time discipline, if available. The default for this flag is enable if support is available, otherwise disable. 529c2daa00SOllivier Robert <dt><tt>monitor</tt> 539c2daa00SOllivier Robert <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 enable. 549c2daa00SOllivier Robert <dt><tt>ntp</tt> 559c2daa00SOllivier Robert <dd>Enables time and frequency discipline. In effect, this switch opens and closes the feedback loop, which is useful for testing. The default for this flag is enable. 569c2daa00SOllivier Robert <dt><tt>pps</tt> 579c2daa00SOllivier Robert <dd>Enables the pulse-per-second (PPS) signal when frequency and time is disciplined by the precision time kernel modifications. See the <a href="kern.html">A Kernel Model for Precision Timekeeping</a> page for further information. The default for this flag is disable. 589c2daa00SOllivier Robert <dt><tt>stats</tt> 599c2daa00SOllivier Robert <dd>Enables the statistics facility. See the <a href="monopt.html">Monitoring Options</a> page for further information. The default for this flag is disable 609c2daa00SOllivier Robert </dl> 619c2daa00SOllivier Robert <dt><tt>includefile <i>includefile</i></tt> 629c2daa00SOllivier Robert <dd>This command allows additional configuration commands to be included from a separate file. Include files may be nested to a depth of five; upon reaching the end of any include file, command processing resumes in the previous configuration file. This option is useful for sites that run <tt>ntpd</tt> on multiple hosts, with (mostly) common options (e.g., a restriction list). 639c2daa00SOllivier Robert <dt><tt>logconfig <i>configkeyword</i></tt> 64ea906c41SOllivier Robert <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. 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: informational messages (<tt>info</tt>), event messages (<tt>events</tt>), statistics messages (<tt>statistics</tt>) and status messages (<tt>status</tt>). 65ea906c41SOllivier Robert <p>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. By default, <tt>logconfig</tt> output is set to <tt>allsync</tt>. 66ea906c41SOllivier Robert <p>Thus, a minimal log configuration could look like this:</p> 679c2daa00SOllivier Robert <p><tt>logconfig=syncstatus +sysevents</tt></p> 68ea906c41SOllivier Robert <dl> 69ea906c41SOllivier Robert <dd> 709c2daa00SOllivier Robert <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> 71ea906c41SOllivier Robert 72ea906c41SOllivier Robert </dl> 73ea906c41SOllivier Robert 74ea906c41SOllivier Robert <dd> 75ea906c41SOllivier Robert <p><tt>logconfig=allsync +allclock</tt></p> 76ea906c41SOllivier Robert <dl> 77ea906c41SOllivier Robert <dd> 789c2daa00SOllivier Robert <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> 79ea906c41SOllivier Robert 80ea906c41SOllivier Robert </dl> 81ea906c41SOllivier Robert <dt><tt>logfile <i>logfile</i></tt> 82ea906c41SOllivier Robert <dl> 83ea906c41SOllivier Robert <dd> 849c2daa00SOllivier Robert <p>This command specifies the location of an alternate log file to be used instead of the default system <tt>syslog</tt> facility. This is the same operation as the <tt>-l </tt>command line option.</p> 85ea906c41SOllivier Robert 86ea906c41SOllivier Robert </dl> 87ea906c41SOllivier Robert <dt><tt>phone <i>dial</i>1 <i>dial</i>2 ...</tt> 88ea906c41SOllivier Robert <dl> 89ea906c41SOllivier Robert <dd>This command is used in conjunction with the ACTS modem driver (type 18). The arguments consist of a maximum of 10 telephone numbers used to dial USNO, NIST or European time services. The Hayes command ATDT is normally prepended to the number, which can contain other modem control codes as well. 90ea906c41SOllivier Robert </dl> 919c2daa00SOllivier Robert <dt><tt>setvar <i>variable</i> [default]</tt> 929c2daa00SOllivier Robert <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. 93ea906c41SOllivier Robert <dt><tt>tinker [ allan <i>allan</i> | dispersion <i>dispersion</i> | freq <i>freq</i> | huffpuff <i>huffpuff</i> | panic <i>panic</i> | step <i>step</i> | stepout <i>stepout</i> ]</tt> 949c2daa00SOllivier Robert <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. 959c2daa00SOllivier Robert <p>The variables operate as follows:</p> 969c2daa00SOllivier Robert <dl> 979c2daa00SOllivier Robert <dt><tt>allan <i>allan</i></tt> 98ea906c41SOllivier Robert <dd>The argument becomes the new value for the Allan intercept, which is a parameter of the PLL/FLL clock discipline algorithm. The value is in seconds with default 1500 s, which is appropriate for most computer clocks.<dt><tt>dispersion <i>dispersion</i></tt> 999c2daa00SOllivier Robert <dd>The argument becomes the new value for the dispersion increase rate, normally .000015 s/s. 1009c2daa00SOllivier Robert <dt><tt>freq <i>freq</i></tt> 1019c2daa00SOllivier Robert <dd>The argument becomes the initial value of the frequency offset in parts-per-million. This overrides the value in the frequency file, if present, and avoids the initial training state if it is not. 1029c2daa00SOllivier Robert <dt><tt>huffpuff <i>huffpuff</i></tt> 1039c2daa00SOllivier Robert <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. 1049c2daa00SOllivier Robert <dt><tt>panic <i>panic</i></tt> 105ea906c41SOllivier Robert <dd>The argument is the panic threshold, by default 1000 s. If set to zero, the panic sanity check is disabled and a clock offset of any value will be accepted. 1069c2daa00SOllivier Robert <dt><tt>step <i>step</i></tt> 107ea906c41SOllivier Robert <dd>The argument is the step threshold, by default 0.128 s. It can be set to any positive number in seconds. If set to zero, step adjustments will never occur. Note: The kernel time discipline is disabled if the step threshold is set to zero or greater than the default. 1089c2daa00SOllivier Robert <dt><tt>stepout <i>stepout</i></tt> 109ea906c41SOllivier Robert <dd>The argument is the stepout timeout, by default 900 s. It can be set to any positive number in seconds. If set to zero, the stepout pulses will not be suppressed. 1109c2daa00SOllivier Robert </dl> 1119c2daa00SOllivier Robert <dt><tt>trap <i>host_address</i> [port <i>port_number</i>] [interface <i>interface_address</i>]</tt> 1129c2daa00SOllivier Robert <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. 1139c2daa00SOllivier Robert <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> 1149c2daa00SOllivier Robert <dt><tt>ttl <i>hop</i> ...</tt> 1159c2daa00SOllivier Robert <dd>This command specifies a list of TTL values in increasing order. up to 8 values can be specified. In manycast mode these values are used in turn in an expanding-ring search. The default is eight multiples of 32 starting at 31. 1169c2daa00SOllivier Robert </dl> 1179c2daa00SOllivier Robert <h4>Files</h4> 1189c2daa00SOllivier Robert <tt>ntp.drift</tt> frequency compensation (PPM) 1199c2daa00SOllivier Robert <hr> 1209c2daa00SOllivier Robert <script type="text/javascript" language="javascript" src="scripts/footer.txt"></script> 1219c2daa00SOllivier Robert </body> 1229c2daa00SOllivier Robert 1239c2daa00SOllivier Robert</html> 124
