From: Harlan Stenn Date: Sun, 18 Jan 2009 00:30:18 +0000 (-0500) Subject: Documentation updates from Dave Mills X-Git-Tag: NTP_4_2_5P155~1 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4c6953b87a0ff0062003234d71fdebae59f0cf94;p=thirdparty%2Fntp.git Documentation updates from Dave Mills bk: 4972781aGAwiBBGPYMSPCEz8K-KoyA --- diff --git a/ChangeLog b/ChangeLog index f4da54c34..92665dc03 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,4 @@ +* Documentation updates from Dave Mills. * CHU frequency updates. * Design assertion fixes for ntp_crypto.c from Dave Mills. (4.2.5p154) 2009/01/13 Released by Harlan Stenn diff --git a/html/assoc.html b/html/assoc.html index 54791a60c..0e5753433 100644 --- a/html/assoc.html +++ b/html/assoc.html @@ -53,7 +53,12 @@

A common configuration for private networks includes one or more core servers operating at the lowest stratum. Good practice is to configure each of these servers as backup for the others using symmetric or broadcast modes. As long as at least one core server can reach a UTC source, the entire subnet can synchronize to it.

If no UTC sources are available to any core server, one of them can provide a simulated UTC source for all other hosts in the subnet. However, only one core server can simulate the UTC source and all direct dependents, called orphan children, must select the same one, called the orphan parent.

A host is enabled for orphan mode using the tos orphan stratum command, where stratum is some stratum less than 16 and greater than any anticipated stratum that might occur with configured Internet time servers. However, sufficient headroom should remain so every subnet host dependent on the orphan children has stratum less than 16. Where no associations for other servers or reference clocks are configured, the orphan stratum can be set to 1. These are the same considerations that guide the local clock driver stratum selection.

-

A orphan parent with no sources shows reference ID LOOP if operating at stratum 1 and 27.0.0.1 (Unix loopback address) otherwise. While ordinary NTP clients use a selection metric based on delay and dispersion, orphan children use a metric computed from the IP address of each core server. Each orphan child chooses the orphan parent as the root server with the smallest value.

+

A orphan parent with no sources shows reference ID LOOP if + operating at stratum 1 and 27.0.0.1 (Unix loopback address) otherwise. + While ordinary NTP clients use a selection metric based on delay + and dispersion, orphan children use a metric computed from the IP + address of each core server. Each orphan child chooses the orphan + parent as the root server with the smallest metric.

For orphan mode to work well, each core server with available sources should operate at the same stratum. All core servers and orphan children should include the same tos command in the configuration file. Each orphan child should include in the configuration file all root servers.

gif diff --git a/html/config.html b/html/config.html index 0891d2340..2aeaafef8 100644 --- a/html/config.html +++ b/html/config.html @@ -13,156 +13,26 @@

Build Options

giffrom Pogo, Walt Kelly

Gnu autoconfigure tools are in the backpack.

-

Last update: 04:01 UTC Sunday, March 02, 2008

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-

Table of Contents

- -
-

Basic Build Options - the configure Utility

-

The following options are for compiling and installing a working version of the NTP distribution. In most cases, the build process is completely automatic. In some cases where memory space is at a premium, or the binaries are to be installed in a different place, it is possible to tailor the configuration to remove such features as reference clock driver support, debugging support, and so forth.

-

Configuration options are specified as arguments to the configure script. Following is a summary of the current options, as of the 4.0.99m version:

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Usage: configure [options] [host]
-

-

Options

-

[defaults in brackets after descriptions] Configuration:

- 
- --cache-file=FILE      cache test results in FILE
- --help                 print this message
- --no-create            do not create output files
- --quiet, --silent      do not print `checking...' messages
- --version              print the version of autoconf that created
-configure
-
-

Directory and File Names

- 
- --prefix=PREFIX        install architecture-independent files in PREFIX [/usr/local]
- --exec-prefix=EPREFIX  install architecture-dependent files in EPREFIX [same as prefix]
- --bindir=DIR           user executables in DIR [EPREFIX/bin]
- --sbindir=DIR          system admin executables in DIR [EPREFIX/sbin]
- --libexecdir=DIR       program executables in DIR [EPREFIX/libexec]
- --datadir=DIR          read-only architecture-independent data in DIR [PREFIX/share]
- --sysconfdir=DIR       read-only single-machine data in DIR [PREFIX/etc]
- --sharedstatedir=DIR   modifiable architecture-independent data in DIR [PREFIX/com]
- --localstatedir=DIR    modifiable single-machine data in DIR [PREFIX/var]
- --libdir=DIR           object code libraries in DIR [EPREFIX/lib]
- --includedir=DIR       C header files in DIR [PREFIX/include]
- --oldincludedir=DIR    C header files for non-gcc in DIR [/usr/include]
- --infodir=DIR          info documentation in DIR [PREFIX/info]
- --mandir=DIR           man documentation in DIR [PREFIX/man]
- --srcdir=DIR           find the sources in DIR [configure dir or ..]
- --x-includes=DIR       X include files are in DIR
- --x-libraries=DIR      X library files are in DIR
- --program-prefix=PREFIX           prepend PREFIX to installed program names
- --program-suffix=SUFFIX           append SUFFIX to installed program names
- --program-transform-name=PROGRAM  run sed PROGRAM on installed program names
-
-

Host Type

- 
- --build=BUILD          configure for building on BUILD [BUILD=HOST]
- --host=HOST            configure for HOST [guessed]
- --target=TARGET        configure for TARGET [TARGET=HOST]
-
-

Optional Packages

- 
- --with-PACKAGE[=ARG]   use PACKAGE [ARG=yes]
- --without-PACKAGE      do not use PACKAGE (same as --with-PACKAGE=no)
-
- openssl-libdir=DIR     OpenSSL object code libraries in DIR [/usr/lib/usr/local/lib/usr/local/ssl/lib]
- openssl-incdir=DIR     OpenSSL header files in DIR [/usr/include/usr/local/include/usr/local/ssl/include]
- crypto=autokey         Use autokey cryptography
- crypto=rsaref          Use the RSAREF library
- electricfence          Compile with ElectricFence malloc debugger
-
-

Optional Features

- 
- --disable-FEATURE      do not include FEATURE (same as
- --enable-FEATURE=no)
- --enable-FEATURE[=ARG] include FEATURE [ARG=yes]
-
- accurate-adjtime       The adjtime() call is accurate
- clockctl               use /dev/clockctl (non root control of system clock)
- debugging              Include debugging code [enable]
- des                    Include support for DES keys [enable]
- dst-minutes=VALUE      Minutes per DST adjustment [60]
- gdt-surveying          Include GDT survey code [disable]
- hourly-todr-sync       If we should sync TODR hourly
- kernel-fll-bug         If we should avoid a (Solaris) kernel FLL bug
- kmem                   Read /dev/kmem for 'tick' and/or 'tickadj'
- md5                    Include support for MD5 keys [enable]
- ntpdate-step           If ntpdate should step the time
- slew-always            Always slew the time
- step-slew              Step and slew the time
- tick=VALUE             Force a value for 'tick'
- tickadj=VALUE          Force a value for 'tickadj'
- udp-wildcard           Use UDP wildcard delivery
-
-

Radio Clocks

-

(these are ordinarily enabled, if supported by the machine and operating system):

- 
- all-clocks             Include drivers for all suitable non-PARSE clocks [enable]
- ACTS                   NIST dialup clock
- ARBITER                Arbiter 1088A/B GPS receiver
- ARCRON_MSF             Arcron MSF receiver
- AS2201                 Austron 2200A or 2201A GPS receiver
- ATOM                   ATOM PPS interface
- AUDIO-CHU              CHU audio decoder
- BANCOMM                Datum/Bancomm BC635/VME interface (requires an explicit --enable-BANCOMM request)
- CHRONOLOG              Chrono-log K-series WWVB receiver
- CHU                    CHU modem decoder
- DATUM                  Datum Programmable Time System
- DUMBCLOCK              Dumb generic hh:mm:ss local clock
- FG                     Forum Graphic GPS
- GPSVME                 TrueTime GPS receiver with VME interface (requires an explicit --enable-GPSVME request)
- HEATH                  HeathKit GC-1000 Most Accurate Clock
- HOPFPCI                HOPF 6039 PCI board
- HOPFSERIAL             HOPF serial clock device
- HPGPS                  HP 58503A GPS Time & Frequency receiver
- IRIG                   IRIG (Audio) Clock
- JUPITER                Rockwell Jupiter GPS receiver
- LEITCH                 Leitch CSD 5300 Master Clock System Driver
- LOCAL-CLOCK            Local clock driver
- MSFEES                 EES M201 MSF receiver
- MX4200                 Magnavox MX4200 GPS receiver
- NMEA                   NMEA GPS receiver
- ONCORE                 Motorola VP/UT Oncore GPS receiver
- PALISADE               Palisade clock
- PCF                    Conrad parallel port radio clock
- PST                    PST/Traconex 1020 WWV/H receiver
- PTBACTS                PTB dialup clock support
- SHM                    Clock attached through shared memory (requires an explicit --enable-SHM request)
- SPECTRACOM             Spectracom 8170/Netclock/2 WWVB receiver
- TRAK                   TRAK 8810 GPS station clock
- TPRO                   KSI/Odetics TPRO/S IRIG Interface
- TRUETIME               Kinemetrics/TrueTime (generic) receiver
- ULINK                  Ultralink WWVB receiver
- USNO                   US Naval Observatory dialup clock
- WWV                    WWV audio receiver
-
-

PARSE Clocks

- 
- parse-clocks           Include drivers for all suitable PARSE clocks [enable]
- COMPUTIME              Diem Computime Radio Clock
- DCF7000                ELV/DCF7000 Clock
- HOPF6021               HOPF 6021 Radio Clock support
- MEINBERG               Meinberg clocks
- RAWDCF                 DCF77 raw time code
- RCC8000                RCC 8000 Radio Clock support
- SCHMID                 SCHMID DCF77 clock support
- TRIMTAIP               Trimble GPS/TAIP Protocol
- TRIMTSIP               Trimble GPS/TSIP Protocol
- VARITEXT               VARITEXT clock
- WHARTON                Wharton 400A Series clock
-
+

Last update: Monday, + December 15, 2008 20:54 UTC

+
+

Most modern software distributions include an autoconfigure utility which + cutomizes the build and install configuration according to the specific + hardware, operating system and file system conventions. For NTP this + utility is called configure, which is run before building and installing + the program components. For most installations no additional actions + are required other than running configure with no options. + However, it is possible to customize the build and install configuration + through the use of configure options.

+

The available options, together with + a concise description, can be displayed by running configure with + the --help option. Various options can be used to reduce the memory + footprint, adjust the scheduling priority, enable or disable debugging + support or reference clock driver support. The options can be used + to specify where to install the program components or where to find + various libraries if they are not in the default place.

+
diff --git a/html/decode.html b/html/decode.html index 45261b9d3..9fcd55283 100644 --- a/html/decode.html +++ b/html/decode.html @@ -138,8 +138,11 @@ telephone modem (ACTS, PTB, etc.) -

The Count Field displays the number of events since the last rv command while the Event Field displays the most recent event message coded as follows:

- +

The Count Field displays the number of events since the last time the + code changed. Upon reaching 15, subsequent events with the same code + are ignored. The Event Field displays the most recent event message + coded as follows:

+
@@ -328,8 +331,10 @@
Code MessagePPS peer (when the prefer peer is valid)
-

The Count Field displays the number of events since the last rv command, while the Event Field displays the most recent event message coded as follows:

- +

The Count Field displays the number of events since the last time the code + changed. Upon reaching 15, subsequent events with the same code are ignored. + The Event Field displays the most recent event message coded as follows:

+
diff --git a/html/ntpd.html b/html/ntpd.html index 54df53c85..d8f3a7456 100644 --- a/html/ntpd.html +++ b/html/ntpd.html @@ -52,11 +52,27 @@

In scenarios where a considerable amount of data are to be downloaded or uploaded over telephone modems, timekeeping quality can be seriously degraded. This occurs because the differential delays on the two directions of transmission can be quite large. In many cases the apparent time errors are so large as to exceed the step threshold and a step correction can occur during and after the data transfer.

The huff-n'-puff filter is designed to correct the apparent time offset in these cases. It depends on knowledge of the propagation delay when no other traffic is present, such as during other than work hours. The filter remembers the minimum delay over the most recent interval measured usually in hours. Under conditions of severe delay, the filter corrects the apparent offset using the sign of the offset and the difference between the apparent delay and minimum delay. The name of the filter reflects the negative (huff) and positive (puff) correction, which depends on the sign of the offset. The filter is activated by the tinker huffpuff command, as described in the Miscellaneous Options page.

Leap Second Processing

-

As provided by international agreement, an extra second is sometimes inserted in Coordinated Universal Time (UTC) at the end of a selected month, usually June or December. The National Institutes of Standards and Technology (NIST) provides an historic leapseconds file at time.nist.gov for retrieval via FTP. When this file, usually called ntp.leapseconds, is installed, ntpd reads it at startup and initializes three leapsecond values: the NTP seconds at the next leap event, the offset of UTC relative to International Atomic Time (TAI) after the leap and the NTP seconds when the leapseconds file expires.

-

If a host does not have the leapsecond values, they can be obtained over the net using the Autokey security protocol. Ordinarily, the leapseconds file is installed on the primary servers and the values flow from them via secondary servers to the clients. When multiple servers are involved, the values with the latest expiration time are used.

+

As provided by international agreement, an extra second is sometimes inserted + in Coordinated Universal Time (UTC) at the end of a selected month, + usually June or December. The National Institutes of Standards and + Technology (NIST) provides an historic leapseconds file at time.nist.gov for + retrieval via FTP. When this file, usually called ntp-leapseconds.list, + is copied and installed in a directory. + The leapfile configuration command specifies the path to + this file. At startup, ntpd reads + it and initializes three leapsecond values: the NTP seconds + at the next leap event, the offset of UTC relative to International + Atomic Time (TAI) after the leap and the NTP seconds when the leapseconds + file expires and should be retrieved again.

+

If a host does not have the leapsecond values, they can be obtained over the net using the Autokey security protocol. Ordinarily, the leapseconds file is installed on the primary servers and the values flow from them via secondary servers to the clients. When multiple servers are involved, the values with the latest expiration time are used.

If the latest leap is in the past, nothing further is done other than to install the TAI offset. If the leap is in the future less than 28 days, the leap warning bits are set. If in the future less than 23 hours, the kernel is armed to insert one second at the end of the current day. If the kernel is enabled, the leap is done automatically at that time; otherwise, the clock is effectively stopped for one second at the leap. Additional details are in the The NTP Timescale and Leap Seconds white paper

-

Dependent servers and clients tally the leap warning bits of surviving servers and reference clocks. When a majority of the survivors show warning, a leap is programmed at the end of the current month. During the month and day of insertion, they operate as above. In this way the leap is propagated at all dependent servers and clients.

-

Additional Features

+

If none of the above provisions are available, dsependent servers and clients + tally the leap warning bits of surviving servers and reference clocks. + When a majority of the survivors show warning, a leap is programmed + at the end of the current month. During the month and day of insertion, + they operate as above. In this way the leap is is propagated at all + dependent servers and clients.

+

Additional Features

A new experimental feature called interleaved modes can be used in NTP symmetric or broadcast modes. It is designed to improve accuracy by avoiding kernel latency and queueing delay, as described on the NTP @@ -67,7 +83,7 @@ as interleaved clients at the same time. Further details are in the white paper NTP Interleaved On-Wire Protocol and the briefing Interleaved - Synchroization Protocols for LANs and Space Data Links.

+ Synchronization Protocols for LANs and Space Data Links.

If ntpd, is configured with NetInfo support, it will attempt to read its configuration from the NetInfo service if the default ntp.conf file cannot be read and no file is specified by the -c option.

In contexts where a host name is expected, a -4 qualifier preceding the host name forces DNS resolution to the IPv4 namespace, while a -6 qualifier forces DNS resolution to the IPv6 namespace.

Various internal ntpd variables can be displayed and configuration options altered while the ntpd is running using the ntpq and ntpdc utility programs.

Code Message