Towli wrote: > Hi all > > I found out that our Inet-Provider has stratum 1 servers available, and > i intended to use these together with our newly acquired DCF77 machinery. > I configured our DFC77 and the 2 external stratum 1 servers on our 2 > core switches to deliver Ntp to the rest of the network... > Unfortunately (?) my switches seem to prefer these external time sources > as opposed to our own internal DCF77 Furthermore i can se (from output > below) that our internal DCF77 is listed as "invalid" ? ? ? Why is that? > I have not yet set up our backup DCF77. When i do - should i loose the 2 > external sources and use solely internal NTPservers or what would your > recommendations / best practice be, based on the output below ? > > Any advice is highly appreciated as i am on thin ice here, and it is an > important task to implement NTP correctly on out network. > > Output: (for "anonymous" purposes in regards to my job i have marked the > external ip's with xxx) > > > /Towli - Denmark > > > #sh ntp ass de > 193.xxx.xxx.xxx configured, our_master, sane, valid, stratum 1 > ref ID .GPS., time CDB44C38.435EEBEB (21:27:52.263 CEST Tue May 12 2009) > our mode client, peer mode server, our poll intvl 64, peer poll intvl 64 > root delay 0.00 msec, root disp 1.69, reach 377, sync dist 9.247 > delay 6.13 msec, offset 4.1194 msec, dispersion 4.30 > precision 2**18, version 3 > org time CDB44C68.7CC60B4F (21:28:40.487 CEST Tue May 12 2009) > rcv time CDB44C68.7C8118AB (21:28:40.486 CEST Tue May 12 2009) > xmt time CDB44C68.7AEB32B4 (21:28:40.480 CEST Tue May 12 2009) > filtdelay = 6.13 6.12 5.57 8.21 5.10 6.33 5.98 > 5.05 > filtoffset = 4.12 6.02 8.18 9.58 13.80 16.39 19.32 > 22.59 > filterror = 0.02 0.99 1.97 2.94 3.92 4.90 6.64 > 8.59 > > 193.zzz.zzz.zzz configured, selected, sane, valid, stratum 1 > ref ID .GPS., time CDB44C3C.894CBE10 (21:27:56.536 CEST Tue May 12 2009) > our mode client, peer mode server, our poll intvl 64, peer poll intvl 64 > root delay 0.00 msec, root disp 1.80, reach 377, sync dist 7.889 > delay 5.43 msec, offset 4.2101 msec, dispersion 3.37 > precision 2**18, version 3 > org time CDB44C74.7DD78E42 (21:28:52.491 CEST Tue May 12 2009) > rcv time CDB44C74.7D760EA9 (21:28:52.490 CEST Tue May 12 2009) > xmt time CDB44C74.7C0F49F3 (21:28:52.484 CEST Tue May 12 2009) > filtdelay = 5.43 6.73 5.94 5.89 6.13 4.82 5.07 > 5.49 > filtoffset = 4.21 5.25 7.64 10.08 12.67 16.30 17.74 > 20.33 > filterror = 0.02 0.99 1.97 2.94 3.92 4.90 5.87 > 7.83 > > 10.200.138.20 configured, sane, invalid, stratum 1 > ref ID .DCF., time CDB44934.00000000 (21:15:00.000 CEST Tue May 12 2009) > our mode client, peer mode server, our poll intvl 1024, peer poll intvl > 1024 > root delay 0.00 msec, root disp 0.00, reach 377, sync dist 21.103 > delay 3.27 msec, offset -11.4426 msec, dispersion 7.02 > precision 2**6, version 3 <------------------------- what does this > precission indicate ? Better or worse than 2**18 ?
Precision is normally expressed as a *negative* power of two! Assuming that somebody dropped the minus signs somewhere, 2**-18 is better than 2**-8. Precision is the smallest possible difference between two successive readings of the clock. _______________________________________________ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions