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diff --git a/contrib/ntp/html/release.htm b/contrib/ntp/html/release.htm deleted file mode 100644 index 9dcef7c..0000000 --- a/contrib/ntp/html/release.htm +++ /dev/null @@ -1,290 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"> -<html> -<head> -<meta name="generator" content="HTML Tidy, see www.w3.org"> -<title>NTP Version 4 Release Notes</title> -</head> -<body> -<h3>NTP Version 4 Release Notes</h3> - -<img align="left" src="pic/hornraba.gif" alt="gif"><a href= -"http://www.eecis.udel.edu/~mills/pictures.htm">from <i>Alice's -Adventures in Wonderland</i>, Lewis Carroll</a> - -<p>The rabbit toots to make sure you read this.<br clear="left"> -</p> - -<hr> -<p>This document was last updated 4 May 2001</p> - -<h4>NTP Version 4 Release Notes</h4> - -<p>This release of the NTP Version 4 (NTPv4) daemon for Unix, VMS -and Windows (NT4 and 2000) incorporates new features and -refinements to the NTP Version 3 (NTPv3) algorithms. However, it -continues the tradition of retaining backwards compatibility with -older versions, except for symmetric mode in NTPv1. Client/server -mode continues to be supported in NTPv1. The NTPv4 version has been -under development for quite a while and isn't finished yet. In -fact, quite a number of NTPv4 features have already been -retrofitted in the current NTPv3, although this version is not -actively maintained by the NTPv4 developer's group.</p> - -<p>The primary purpose of this release is to verify the remaining -new code compiles and runs in the various architectures, operating -systems and hardware complement that can't be verified here. Of -particular interest are Windows 2000, VMS and various reference -clock drivers. As always, corrections and bugfixes are warmly -received, especially in the form of context diffs.</p> - -<p>This note summarizes the differences between this software -release of NTPv4, called ntp-4.x.x, and the previous NTPv3 version, -called xntp3-5.x.x. Additional information on protocol -compatibility details is in the <a href="biblio.htm">Protocol -Conformance Statement</a> page.</p> - -<ol> -<li> -<p>Most calculations are now done using 64-bit floating double -format, rather than 64-bit fixed point format. The motivation for -this is to reduce size, improve speed and avoid messy bounds -checking. Workstations of today are much faster than when the -original NTP version was designed in the early 1980s, and it is -rare to find a processor architecture that does not support -floating double. The fixed point format is still used with raw -timestamps, in order to retain the full precision of about 212 -picoseconds. However, the algorithms which process raw timestamps -all produce fixed point differences before converting to floating -double. The differences are ordinarily quite small so can be -expressed without loss of accuracy in this format.</p> -</li> - -<li> -<p>The clock discipline algorithm has been redesigned to improve -accuracy, reduce the impact of network jitter and allow an increase -in poll intervals to well over one day with only moderate sacrifice -in accuracy. The NTPv4 design allows servers to increase the poll -intervals even when synchronized directly to the peer. In NTPv3 the -poll interval in such cases was clamped to the minimum, usually 64 -s. For those servers with hundreds of clients, the new design can -dramatically reduce the network load.</p> -</li> - -<li> -<p>This release includes support for the <a href= -"http://www.eecis.udel.edu/~mills/resource.htm"><i> -nanokernel</i></a> precision time kernel support, which is now in -stock Linux and FreeBSD kernels. If a precision time source such as -a GPS timing receiver or cesium clock is available, kernel -timekeeping can be improved to the order less than one microsecond. -The older precision time kernel for the Alpha continues to be -supported.</p> -</li> - -<li> -<p>This release includes support for Autokey public-key -cryptography, which is the preferred scheme for authenticating -servers to clients. It uses NTP header extensions fields documented -in: Mills, D.L. Public-Key cryptography for the Network Time -Protocol. Internet Draft draft-ietf-stime-ntpauth-00.txt, -University of Delaware, June 2000, 36 pp. <a href= -"http://www.eecis.udel.edu/~mills/database/memos/draft-ietf-stime-ntpauth-00.txt"> -ASCII</a> and implemented in this release. The design provides for -orderly key refreshment and does not require public keys and -related media to be copied from one machine to another. Specific -information about Autokey cryptography is contained in the <a href= -"authopt.htm">Authentication Options</a> page and links from -there.</p> -</li> - -<li> -<p>NTPv4 includes two new association modes which in most -applications can avoid per-host configuration altogether. Both of -these are based on IP multicast technology and Autokey -cryptography. They provide for automatic discovery and -configuration of servers and clients without identifying servers or -clients in advance. In multicast mode a server sends a message at -fixed intervals using specified multicast group addresses, while -clients listen on these addresses. Upon receiving the message, a -client exchanges several messages with the server in order to -calibrate the multicast propagation delay between the client and -server. In manycast mode a client sends a message to a specified -multicast group address and expects one or more servers to reply. -Using engineered algorithms, the client selects an appropriate -subset of servers from the messages received and continues in -ordinary client/server operation. The manycast scheme can provide -somewhat better accuracy than the multicast scheme at the price of -additional network overhead. See the <a href="assoc.htm"> -Association Management</a> page for further information.</p> -</li> - -<li> -<p>There are two burst mode features available where special -conditions apply. One of these is enabled by the <tt>iburst</tt> -keyword in the <tt>server</tt> configuration command. It is -intended for cases where it is important to set the clock quickly -when an association is first mobilized. The other is enabled by the -<tt>burst</tt> keyword in the <tt>server</tt> configuration -command. It is intended for cases where the network attachment -requires an initial calling or training procedure. See the <a href= -"assoc.htm">Association Management</a> page for further -information.</p> -</li> - -<li> -<p>The reference clock driver interface is smaller, more rational -and more accurate. Support for pulse-per-second (PPS) signals has -been extended to all drivers as an intrinsic function. Most of the -drivers in NTPv3 have been converted to this interface, but some, -including the PARSE subinterface, have yet to be overhauled. New -drivers have been added for several GPS receivers now on the market -for a total of 39 drivers. Drivers for the Canadian standard time -and frequency station CHU, the US standard time and frequency -stations WWV/H and for IRIG signals have been updated and -capabilities added to allow direct connection of these signals to -the Sun audio port <tt>/dev/audio</tt>.</p> -</li> - -<li> -<p>In all except a very few cases, all timing intervals are -randomized, so that the tendency for NTPv3 to self-synchronize and -bunch messages, especially with a large number of configured -associations, is minimized.</p> -</li> - -<li> -<p>In NTPv3 a large number of weeds and useless code had grown over -the years since the original NTPv1 code was implemented almost -twenty years ago. Using a powerful weedwacker, much of the -shrubbery has been removed, with effect a substantial reduction in -size of almost 40 percent.</p> -</li> - -<li> -<p>The entire distribution has been converted to gnu <tt> -automake</tt>, which should greatly ease the task of porting to new -and different programming environments, as well as reduce the -incidence of bugs due to improper handling of idiosyncratic kernel -functions.</p> -</li> -</ol> - -<h4>Nasty Surprises</h4> - -<p>There are a few things different about this release that have -changed since the latest NTP Version 3 release. Following are a few -things to worry about:</p> - -<ol> -<li> -<p>As required by Defense Trade Regulations (DTR), the -cryptographic routines supporting the Data Encryption Standard -(DES) have been removed from the base distribution. These routines -are readily available in most countries from RSA Laboratories. -Directions for their use are in the <a href="build.htm">Building -and Installing the Distribution</a> page.</p> -</li> - -<li> -<p>As the result of the above, the <tt>./authstuff</tt> directory, -intended as a development and testing aid for porting cryptographic -routines to exotic architectures, has been removed. Developers -should note the NTP authentication routines use the interface -defined in the <tt>rsaref2.0</tt> package available from RSA -laboratories.</p> -</li> - -<li> -<p>The enable and disable commands have a few changes in their -arguments see the <tt>ntpd</tt> <a href="confopt.htm">Configuration -Options</a> page for details. Note that the <tt>authenticate</tt> -command has been removed.</p> -</li> - -<li> -<p>The <tt>ppsclock</tt> line discipline/streams module is no -longer supported. This function is now handled by the <a href= -"driver22.htm">PPS Clock Discipline</a> driver, which uses the new -PPSAPI application program interface proposed by the IETF. Note -that the <tt>pps</tt> configuration file command has been obsoleted -by the driver. See the <a href="pps.htm">Pulse-per-second (PPS) -Signal Interfacing</a> page for further information.</p> -</li> - -<li> -<p>Several new options have been added for the <tt>ntpd</tt> -command line. For the inveterate knob twiddlers several of the more -important performance variables can be changed to fit actual or -perceived special conditions. It is possible to operate the daemon -in a one-time mode similar to <tt>ntpdate</tt>, which program is -headed for retirement. See the <a href="ntpd.htm"><tt>ntpd</tt> - -Network Time Protocol (NTP) daemon</a> page for the new -features.</p> -</li> - -<li> -<p>To help reduce the level of spurious network traffic due to -obsolete configuration files, a special control message called the -kiss-of-death packet has been implemented. If enabled and a packet -is denied service or exceeds the client limie, a compliant server -will send this message to the client. A compliant client will cease -further transmission and send a message to the system log. See the -<a href="accopt.htm">Authentication Options</a> page for further -information.</p> -</li> - -<li> -<p>An experimental filter algorithm called huff-n'-puff has been -implemented to reduce errors under conditions of severe assymetric -delays characteristic of <tt>ppp</tt> connections with telephone -modems and downloading or uploading considerable traffic. See the -<a href="ntpd.htm">ntpd - Network Time Protocol (NTP) daemon</a> -page for further information.</p> -</li> -</ol> - -<h4>Caveats</h4> - -<p>This release has been compiled and tested on several systems, -including SunOS 4.1.3, Solaris 2.5.1-2.8, Alpha 4.0, Ultrix 4.4, -Linux, FreeBSD and HP-UX 10.02. It has been compiled and tested on -Windows NT, but not yet on any other Windows version or for VMS. We -are relying on the NTP volunteer corps to do that. Known problems -are summarized below:</p> - -<ol> -<li> -<p>The latest NTPv4 <tt>ntpdc</tt> does not work with previous -versions of <tt>ntpd</tt> and previous versions of <tt>ntpdc</tt> -do not work with latest <tt>ntpd</tt>. This situation is -regrettable and may be fixed in future; however, it is necessary in -order for the autokey function to retrieve canonical names and -certificates from directory services such as Secure DNS.</p> -</li> - -<li> -<p>The precision time support in stock Solaris 2.6 has bugs that -were fixed in 2.7. A patch is available that fixes the 2.6 bugs. -The 2.6 kernel discipline has been disabled by default. For -testing, the kernel can be enabled using the <tt>enable kernel</tt> -command either in the configuration file or via <tt>ntpdc</tt>.</p> -</li> - -<li> -<p>The HTML documentation has been partially updated. However, most -of the NTPv3 documentation continues to apply to NTPv4. Until the -update happens, what you see is what you get. We are always happy -to accept comments, corrections and bug reports. However, we are -most thrilled upon receipt of patches to fix the dang bugs.</p> -</li> -</ol> - -<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> - |
