On Fri, 9 Jan 2009, Folkert van Heusden wrote:
>>>> transmitted 4, in filter 4 >>>> reference time: cd0c473b.73087696 Mon, Jan 5 2009 9:45:47.449 >>>> originate timestamp: cd0f5b7d.d6ff250b Wed, Jan 7 2009 17:49:01.839 >>>> transmit timestamp: cd0f5b7d.cf7e90ff Wed, Jan 7 2009 17:49:01.810 >>>> filter delay: 0.03938 0.03787 0.03879 0.03783 >>>> 0.00000 0.00000 0.00000 0.00000 >>>> filter offset: 0.023514 0.023034 0.023029 0.023167 >>>> 0.000000 0.000000 0.000000 0.000000 >>>> delay 0.03783, dispersion 0.00012 >>>> offset 0.023167 >>>> >>>> 7 Jan 17:49:01 ntpdate[22293]: no server suitable for synchronization >>>> found >>>> >>>> ( http://nmi.nl/index.php?pageId=1215&lg=nl ) >>> >>> A wireshark capture shows that it sends a bogu reftime ... >>> Reference Clock Update Time: Jan 5, 2009 08:45:47,4493 UTC > > Does a valid NTP source need to set the reftime to something valid? Does > the ntp spec say so? Yes. Quote 'Time when the system clock was last set or corrected, in NTP timestamp format' unquote. > >>> Originate Time Stamp: Jan 8, 2009 10:15:39,0507 UTC >>> Receive Time Stamp: Jan 8, 2009 10:15:39,0375 UTC >>> Transmit Time Stamp: Jan 8, 2009 10:15:39,0376 UTC >>> >>> The Root dispersion does not look too healthy, too... >>> Root Dispersion: 3,9689 sec > > The root dispersion, that is the amount of time this server is > behind/faster than the stratum 0 device? dispersion is part of the error statistics. See the spec, or better yet buy the book. See Chapter 11. Smaller is better, for obvious reasons, but it won't be zero. > So optimally that should be 0? > Is there a limit defined in the ntp spec? MAXDIST. 1 second in the reference implementation, which is a bit generous. > > > Folkert van Heusden > > -- > Ever wonder what is out there? Any alien races? Then please support > the s...@home project: setiathome.ssl.berkeley.edu > ---------------------------------------------------------------------- > Phone: +31-6-41278122, PGP-key: 1F28D8AE, www.vanheusden.com > _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
