1258945SrobertoNotes for NTP Version 3 2258945Sroberto 3258945SrobertoThis version operates in much the same manner as Version 2 with the 4258945Srobertofollowing changes and additions: 5258945Sroberto 6258945Sroberto1. The protocol machinery operates in conformance with the RFC1305 NTP 7258945Sroberto Version 3 specification. The most visible characteristic of this 8258945Sroberto version is that the poll intervals for all polls, even selected 9258945Sroberto ones, is significantly increased. This is especially desirable when 10258945Sroberto serving a large client population. This implementation supports 11258945Sroberto previous versions as non-configured peers; for version-2 configured 12258945Sroberto peers a "version 2" keyword should be included on the "peer" line. 13258945Sroberto 14258945Sroberto2. The configuration file has a new keyword: statfile <file>, where 15258945Sroberto <file> is the name of a statistics file." When present, each clock 16258945Sroberto update generates an entry of the form: 17258945Sroberto 18258945Sroberto <day> <sec>.<frac> <addr> <status> <offset> <delay> <disp> 19258945Sroberto 20258945Sroberto where <day> is the modified Julian day, <sec>.<frac> is the time of 21258945Sroberto day, <addr> is the peer address and <status> is the peer status. 22258945Sroberto The <offset>, <delay> and <disp> are the measured offset, delay and 23258945Sroberto dispersion, respectively, of the peer clock relative to the local 24258945Sroberto clock. About once per day the current file is closed and a new one 25258945Sroberto created with names <file>.<gen>, where <gen> starts at one and 26258945Sroberto increments for each new generation. 27258945Sroberto 28258945Sroberto3. A number of additional platforms are supported. See ./Config file 29258945Sroberto for details. 30258945Sroberto 31258945Sroberto4. A driver for the TrueTime 468DC GOES Synchronized Clock is 32258945Sroberto included. This driver (refclock_goes.c) should also work for other 33258945Sroberto TrueTime radio clocks, since all use the same format. 34258945Sroberto 35258945Sroberto5. A replacement driver for the Spectracom 8170 WWVB Synchronized 36258945Sroberto Clock is included. This driver (refclock_wwvb.c) (a) does not 37258945Sroberto require a 1-pulse-per-second signal, (b) supports both format 0 38258945Sroberto (original 8170) and format 2 (Netclock/2 and upgraded 8170), (c) 39258945Sroberto can be connected to more than one computer and (d) automatically 40258945Sroberto compensates for all serial baud rates. 41258945Sroberto 42258945Sroberto6. A driver for the German time/frequency station DCF77 is included. 43258945Sroberto This requires a special STREAMS module. 44258945Sroberto 45258945Sroberto7. In Version 2 special line-discipline modules were required for the 46258945Sroberto CHU and WWVB drivers. This code continues to work in Version 3, 47258945Sroberto although it is no longer needed for the WWVB driver. However, this 48258945Sroberto code does not work under STREAMS, as used in SunOS 4.1.1. 49258945Sroberto Equivalent STREAMS modules are supplied with Version 3. 50258945Sroberto 51258945Sroberto8. Support for an external 1-pulse-per-second (pps) signal is 52258945Sroberto provided. The signal is connected to a serial port (see 53258945Sroberto xntpd/ntp_loopfilter.c for details). When present the leading edge 54258945Sroberto of the pulse establishes the on-time epoch within an interval 55258945Sroberto established by the selected radio clock or other NTP time server. 56258945Sroberto Use of the pps is indicated when the tattletale displayed by ntpq 57258945Sroberto changes from "*" to "o". 58258945Sroberto 59258945Sroberto9. The clock-selection and poll-update procedures have been modified 60258945Sroberto slightly in order to achieve better performance on high speed LANs 61258945Sroberto with compromise in performance on typical WANs. 62258945Sroberto 63258945Sroberto10. In order to comply with U.S. Commerce Department regulations, the DES 64258945Sroberto encryption routine lib/authdes.c cannot be exported. For exportable 65258945Sroberto versions of this distribution a DES-encrypted version of this routine 66258945Sroberto lib/authdes.c.des is included along with an unencrypted version 67258945Sroberto lib/authdes.c.export, which allows normal operation, but without the 68258945Sroberto NTP authentication feature. Further information is available in the 69258945Sroberto lib/authdes.c.export file. 70258945Sroberto 71258945Sroberto11. As an alternative to the DES-based authentication mechanism, an 72258945Sroberto implementation of the RSA Message Digest 5 algorithm is provided. 73258945Sroberto (see applicable copyright information in the library files). 74258945Sroberto 75258945Sroberto12. A driver for the Magnavox MX4200 GPS clock. 76258945Sroberto 77258945Sroberto13. A STREAMS module which captures carrier-detect data-lead transitions to 78258945Sroberto connect a precision source of 1-pps, yet avoid the ugly overhead in the 79258945Sroberto usual STREAMS processing. See the ppsclock subdirectory. 80258945Sroberto 81258945Sroberto14. Support for the Apple A/UX operating system and enhanced support for the 82258945Sroberto Hewlet-Packard HP/UX operating system. See the various README and Config 83258945Sroberto files for further information. 84258945Sroberto 85258945SrobertoSee the COPYRIGHT file for authors and copyright information. Note that some 86258945Srobertomodules in this distribution contain copyright information that supersedes 87258945Srobertothe copyright information in that file. 88258945Sroberto 89258945SrobertoIf I missed something or neglected to give due credit, please advise. 90258945Sroberto 91258945SrobertoDavid L. Mills 92258945SrobertoUniversity of Delaware 93258945Sroberto31 May 1992, amended 23 July 1992, 25 October 1992 94258945Sroberto 95258945SrobertoBugs and notes 96258945Sroberto 97258945SrobertoA bug in the original tty_clk_STREAMS.c module has been fixed. 98258945Sroberto 99258945SrobertoThe poll-interval randomization feature of poll_update (in 100258945Srobertoxntpd/ntp_proto.c) has been extended to apply when the poll interval is 101258945Srobertoincreased, as well as reduced. This spreads the update messages in time 102258945Srobertoand helps avoid unpleasant bursts of messages. 103258945Sroberto 104258945SrobertoIn the clock_select algorithm the peers selected for combining are 105258945Srobertolimited to those survivors at the lowest stratum, not the entire list. 106258945SrobertoThis helps avoid whiplash when large numbers of peers are at the same 107258945Srobertostratum. 108258945Sroberto 109258945SrobertoThe number formerly displayed by ntpq as "compliance" is now the time 110258945Srobertoconstant of integration. 111258945Sroberto 112258945SrobertoThe DNS resolver xntpd/ntp_intres.c is now integrated into xntpd, making 113258945Srobertoconfiguration of multiple hosts easier. 114258945Sroberto 115258945SrobertoSystem and peer event are now written to the system log at priority 116258945SrobertoLOG_INFO. 117258945Sroberto 118258945SrobertoThe leap-second code was fixed to avoid broadcasting leap warnings on 119258945Srobertoall except the last day of June and December. 120