[ntp:questions] Help appreciated

Towli towli at oldboyz.dk
Tue May 12 19:41:25 UTC 2009


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 ?
org time CDB44944.71A00000 (21:15:16.443 CEST Tue May 12 2009)
rcv time CDB44944.74F8FC00 (21:15:16.456 CEST Tue May 12 2009)
xmt time CDB44944.7422D23A (21:15:16.453 CEST Tue May 12 2009)
filtdelay =     3.27    1.57    2.12    1.37    1.34    1.43    1.34    2.64
filtoffset =  -11.44   -5.19   -5.52   -1.00   -2.57   -1.61   -1.85    0.17
filterror =     0.02    7.83   14.65   22.46   30.27   38.09   42.01   49.82 




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