Use this value to control whether search engines should index your time server's web page.

Default contents:

User-agent: *
Disallow /
Disallow *

Default contents:

body {background:#e0ddd0; margin:15px 0px}
table.main {background-color:#ffe; border-collapse:collapse; border:solid #000 0px; width:95%; margin:0px; margin-left:auto; margin-right:auto;}
table.main td {padding:0px 1%; line-height:130%;}
.maintop {font: bold small sans-serif; text-align:left; color:#fff; background-color:#18204f; height:40px;}
.mainleft {font:x-small sans-serif; text-align:center; vertical-align:top; background-color:#ffe;}
.mainright {font:x-small sans-serif; text-align:center; color:black; vertical-align:middle; background-color:#ececee;}
.mainbottom {font:bold x-small sans-serif; text-align:right; background-color:#18204f; height:40px;}
table.left {background-color:#ffe; width:100%;}
table.right {background-color:#ececee; width:100%;}
.l {text-align:right;}
.r {text-align:left;}
.refresh {display:block; float:right; margin:0 5px 0 0; background-color:#18204f; cursor:pointer; padding:5px 1%; border-top:1px solid #999; border-left:1px solid #888; border-right:1px solid #444; border-bottom:1px solid #666; line-height:120%; text-decoration:none; color:#ccc;}
a:hover {background-color:#456; color:#ffe;}
hr {border:0; color:#000; background-color:#999; height:1px; width:70%; text-align:center; vertical-align:top;}

You should not change this number unless instructed by techsupport.

Changes to this setting take effect immediately after the next group of collected samples is ready for analysis. You do not need to restart the service. You should clear your clock history using the command dtcheck -resettimings before changing this value. Allowed values are:

• Automatic - On Vista/2008/Win7/2008r2 machines, Automatic will use the median value from each group of samples. On all other versions of Windows, it will use the arithmetic mean (average) of each group of samples.
  
• Average - The arithmetic mean of values
  
• Median - The median number in the array of values
  
• Toss - average of values excluding the highest high and lowest low
  
• RMS - the quadratic mean (signed root-mean-square) of the array of values
  
• Disabled - no statistical analysis is retained for future comparison
  

Important: This is a machine-specific setting and should not be included in installation templates or copied to other machines via mass registry imports.

If not present or set to zero, Domain Time will use a value of 2 seconds.

Modern CPUs (ones with Invariant TSC) generally have better timing performance with this value set to False. You can check to see if you have an Invariant TSC by running the command-line DTCheck program:

• If set to NISTLF, the output consists of an LF, followed by the normal NIST format string, followed by a space and then a terminating LF.
  
• If set to plain NIST, there is no leading LF, and the terminator is a CRLF (no extra space).
  
• You may also use a ddd MMM yyyy format string . Any legal combination of specifiers in Microsoft's GetDateFormat API are acceptable.
  

You may list services by their display names (e.g. "Disk Defragmenter") or by their internal service names (e.g. "defragsvc"). List services one per line, without quotation marks. Domain Time will only attempt to start services that are listed, not yet running, and set to manual startup.

Important: If Domain Time cannot set the clock for some reason (invalid sources, firewall settings, etc.), then services you have set to manual start will not be started.

The older registry entry controlling this function, Max Slew Correction (seconds), has been deprecated.

CAUTION: Enable this option with care. Use of this option may prevent Domain Time from successfully being able to synchronize with a time source if the time correction is too large to accomplish using slewing. See the Max Slew Correction (milliseconds) registry setting for more info.

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IMPORTANT: Unlike with versions prior to v5.1, the behavior of this setting is NOT modified by the Override Max Disparity registry setting. If Never Step Clock is enabled, the clock will never be stepped, regardless of any other settings.

As of v5.1,, Domain Time uses the Allow Stepping setting (see above) to provide greater control of the stepping process. If your machine running an older version of Domain Time had Never Step Clock specified in the registry, the value will be translated to an Allow Stepping value of zero when upgrading to v5.x or later. See the Stepping Options dialog of the Clock Control property page to set the options.

In most cases, it is better to set the Stepping Options with the behavior you want than to enable Never Step Clock.

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Note: This value is related to and may be overwritten in some circumstances based on the NTP Server Stratum value described below. When the NTP Server Stratum is set to 0 (Automatic) and NTP Server RefID is set to Dynamic, Domain Time will typically populate the RefID field with the IP address of its last known time source if the time was derived from a single machine, or 0.0.0.0 if multiple machines were included in the time analysis. LOCL may sometimes appear under certain configurations for compatibility with Active Directory.

If the NTP Server RefID value is set to Static, the RefID field will typically contain word GREY (or the dotted-quad numeric equivalent). Setting the NTP Server Stratum to 1 will force the NTP Server RefID to be Static. You may use either Dynamic or Static with any other value of NTP Server Stratum (2 - 15).

Note that when you set the Domain Time Server to "Do not set this machine's time" on the Obtain the Time property page, there is no external time source, so the RefID field will contain zeros. Some older NTP clients interpret this as the machine not being a valid time source and therefore refuse to synchronize with the Server. In this case, set the NTP Server Stratum value to 1 and restart the service.

As of 5.2.b.20150516, when set to automatic assignment Domain Time selects a stratum number based on on strata reported by its time sources (including PTP, which uses "stepsAway" to correspond, roughly, with NTP strata).

Since Domain Time can use multiple sources with multiple protocols, there may not be an ultimate single stratum from which time was received. In these cases, Domain Time takes the highest-level stratum reported by all used sources, and adds one to derive its own stratum number. So, for example, if Domain Time obtains its time from a PTP grandmaster directly, it will report itself as stratum 2. If it receives its time from three NTP sources, two of which report stratum 1, and one of which reports stratum 2, Domain Time will report itself as stratum 3. If all three NTP sources reported stratum 1, Domain Time would report stratum 2, and so forth.

Versions prior to 5.2.b.20150516, automatic assignment applied a default Stratum depending on the type of Server Role selected:

• Master Server: Stratum 2
• Slave Server: Stratum 3
• Independent Server: Stratum 2

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IMPORTANT: As of v5.1, none of these settings modify the Never Step Clock setting (see above). Note that this is a change in behavior from older versions. Enabling Never Step Clock effectively limits corrections to the Maximum Slew Correction (milliseconds) value, even if a larger correction would otherwise be permitted by Override Max Disparity.

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• 0 or not present (Auto)
  Domain Time will override the disparity settings during startup, on Clock Change Monitor event detection, receiving sync triggers/cascades from management components, or from Control Panel applet (CPL) signals.

• 1 (Always)
  Domain Time will always override the disparity settings. This is the same as not having disparity settings at all. Always honors Never Step Clock setting.

• 2 (Never)
  Domain Time will never override the disparity settings. Always honors Never Step Clock. This option may prevent your machine from syncing until you manually set the time to within the set Min/Max disparity range. If the machine is a Domain Time Server, it will normally refuse to serve the time until its own time has been set, so selecting a value of 2 may impact your entire network.

• 3 (Startup only)
  Domain Time will override the disparity settings only until the first time after startup that it has set its own time correctly. Thereafter, it behaves as if you had set the option to 2.

• 4 (Limit CCM)
  Clock Change Monitor signals do not override the disparity settings. Startup, management, or CPL signals will override the disparity settings.

To prevent accepting obviously-wild time corrections, Domain Time will (by default) refuse to set the time outside of a defined range of acceptable correction. Backwards-correction is limited to the build date of the software - 1 year. Forward-correction is limited to 11:59:59 on 12/31/2036 due to NTP and UNIX Year 2038 date calculation issues.

However, Windows itself will allow setting the local clock outside of this sanity-checked range. Set this value to True to permit Domain Time to set the clock to any time/date the operating system will allow.

Set this value to the beginning port number (n) of a range you want Domain Time to use for its generic outgoing sockets. Domain Time will attempt to use (n) through (n + 50) to bind its generic outgoing sockets. If none of the ports (n) through (n + 50) are available, Domain Time will revert to letting the system choose an ephemeral port.

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IMPORTANT: Be very careful not to specify any well-known ports or IANA-registered ports for your range, and only set this value if you have a specific problem that you know will be solved by changing the ephemeral ports Domain Time uses.

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Note: Because this value is highly machine-specific, it is not included in template imports or exports. You must set it individually on each machine.

Note: On Domain Time Client, these functions are located in the Client Settings key.

In general, you should not edit these settings manually. Use the Control Panel applet to configure your settings instead.

However, as of v5.2.b.20170922, the applet setting for Minimum Correction (MinDisparity) has been removed. The setting for this value defaults to 0x1, but if you upgraded over a previous version with a higher setting, you may edit the binary key to change it. The Minimum Correction setting is a DWORD, starting at offset 14, stored in little-endian order, as shown below.

The default should be 01 00 00 00, see this example:

For example, HighLow,Latency would apply first the Highlow filter, then if at least five samples remain, the latency Filter. Stratum,Latency,Delta would first apply the Stratum filter; then if at least five samples remain, the Latency filter; then, if at least five samples remain, the Delta filter. Changes to the list of prefilters are recognized only when parameters are reloaded (server stop/restart, machine reboot, a CPL-initiated sync, or a DTCheck /reload).

Prefilter operations are: