Towli wrote: > > "David Woolley" <[email protected]> skrev i > meddelelsen news:[email protected]... >> Towli wrote: >>> >>> "David Woolley" <[email protected]> skrev i >>> meddelelsen news:[email protected]... >> >>>> >>>>>> #sh ntp ass de >>>> >>>> What command are you running? >>> >>> Show ntp association detail - sry >> >> What OS are you using; that command is not part of the standard ntpd >> distribution. > > Im using Cisco 3750 switches synching with a DFC77 appliance box and > external (InetProviders) Stratum 1 servers. > > I am really trying to understand this, and i feel a little stupid, > -perhaps i dont get it because english is not my native language: > Why is my 3750 switch reporting a precison of 2**-6 when using my > appliance DCF77 box, but reporting precison of 2**-18 when talking about > the external Gps-servers. > If i erase the ntp clock-period from my switches when they are in synch > with my appliance box - would the precision improve ? > > /T > >
Precision is the smallest possible difference between two successive readings of the clock. It has nothing to do with accuracy. Precision is usually specified as a negative power of two; e.g. a precision of -10 says that the clock "ticks" each represent 1/1024 seconds or approximately one millisecond. Solaris, running on SPARC hardware has a precision of -21 which is somewhere near 1 microsecond. Your switches were designed to switch packets! Any timekeeping they do is almost certainly for the purpose of time stamping log files. The events they might timestamp probably occur on a scale of milliseconds, centiseconds, or even deciseconds (1/10 seconds). And don't worry about your English; it's certainly better than my Danish (non-existent) or my Deutch (almost non-existent). _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
