[ntp:questions] NTP.ORG MEINBERG KEEP TIME ACCURATE to 10MS
David Lord
snews at lordynet.org
Thu Nov 15 09:06:21 UTC 2012
Richard B. Gilbert wrote:
> On 11/14/2012 12:02 AM, E-Mail Sent to this address will be added to the
> BlackLists wrote:
>> gbusenberg at yahoo.com wrote:
>>> I am now left with two lines in ntp.conf
>>> driftfile "C:\Program Files\NTP\etc\ntp.drift"
>>> server 10.1.126.204 iburst minpoll 5
>>
>> There have been plenty of improvemnets since 4.2.6p5 circa 2011Dec24
>> <http://www.davehart.net/ntp/win/x86/ntp-4.2.7p310-win-x86-debug-bin.zip>
>> <http://www.davehart.net/ntp/win/x86/ntp-4.2.7p310-win-x86-debug-sym.zip>
>>
>> # ALL (Clients and/or Servers)
>> # Start the Service with C:\Program Files\NTP\bin\ntpd.exe -U 3 -M -g
>> -c "C:\Program Files\NTP\etc\ntp.conf"
>> # the -g will prevent a panic stop if the time needs to be steped
>> when started
>>
>> # ntp.conf
>> driftfile "C:\Program Files\NTP\etc\ntp.drift"
>> statsdir "C:\Program Files\NTP\etc\"
>> enable monitor
>> enable stats
>> statistics loopstats peerstats
>> keys "C:\Program Files\NTP\etc\ntp.keys" # e.g. contains: 123 M
>> YOUR_MD5_KEY
>> trustedkey 123
>> tos cohort 1 orphan 11
>> restrict default limited kod nomodify notrap
>> restrict 127.0.0.1
>> restrict source nomodify
>> broadcastclient
>> manycastserver 224.0.1.1
>> multicastclient 224.0.1.1 key 123 preempt
>> manycastclient 224.0.1.1 key 123 preempt
>> pool pool.ntp.org preempt # Won't hurt anything if the
>> internet can't be reached
>> server 10.1.126.204 iburst key 123
>>
>> # If you address the server by name append preempt
>> # Let NTP worry about the minpoll and maxpoll for LAN devices
>>
>> # They should all try to sync to 10.1.126.204
>> # If they can't reach 10.1.126.204 they should all try to stick together
>>
>> # NTP expects to be run continuously; After a Boot/Reboot/Restart/...
>> # give the systems 30 minutes to stabilize polls and temperature
>> # before expecting too much from the ntpq stats
>>
> 30 minutes is more than a little optimistic! NTPD needs something like
> ten hours to stabilize with the best time you are going to get. Thirty
> minutes after startup is about when NTPD gets days, hours, and minutes
> right. The next nine and a half hours will be devoted to improve the
> accuracy.
Last night I updated kernel on ntp0.lordynet.org.uk and
system was rebooted at around 23:53.
NetBSD-6
ntpd 4.2.6p5
10 minutes after reboot:
Offset hasn't stabilised and is still 0.000 us but server has
just begun to reply to queries.
Thu Nov 15 00:03:00 GMT 2012
remote refid st t when poll reach delay offset
jitter
==============================================================================
*SHM(0) .MSFa. 0 l 20 64 377 0.000 0.096
0.279
+ntp1.lordynet.o 81.187.61.74 2 u 28 64 77 0.443 -0.050
0.057
+ntp1.aa.net.uk 195.66.241.3 2 u 100 256 1 13.600 0.012
0.216
xxxxxxxxxxxxxxx 131.188.3.222 2 u 5 256 7 24.311 -0.092
0.130
xxxxxxxxxxxxxxx 194.66.31.14 2 u 255 256 3 19.934 3.285
0.306
xxxxxxxxxxxxxxx 195.66.241.2 2 u 9 256 7 13.660 -0.877
0.204
xxxxxxxxxxxxxxx 195.66.241.2 2 u - 256 7 13.675 -0.312
0.239
ntp_gettime() returns code 0 (OK)
time d44eafb5.c6300000 Thu, Nov 15 2012 0:03:01.774, (.174837786),
maximum error 304516 us, estimated error 16 us, TAI offset 0
ntp_adjtime() returns code 0 (OK)
modes 0x0 (),
offset 0.000 us, frequency -47.095 ppm, interval 4 s,
maximum error 304516 us, estimated error 16 us,
status 0x1 (PLL),
time constant 3, precision 0.000 us, tolerance 496 ppm,
pps frequency -47.095 ppm, stability 0.000 ppm, jitter 0.000 us,
intervals 0, jitter exceeded 0, stability exceeded 0, errors 0.
30 minutes after reboot:
Thu Nov 15 00:23:00 GMT 2012
remote refid st t when poll reach delay offset
jitter
==============================================================================
*SHM(0) .MSFa. 0 l 4 64 377 0.000 -0.117
0.400
+ntp1.lordynet.o 81.187.61.74 2 u 8 64 377 0.417 -0.235
0.120
-ntp1.aa.net.uk 195.66.241.3 2 u 7 256 17 13.426 0.364
0.493
+xxxxxxxxxxxxxxx 131.188.3.222 2 u 141 256 177 24.311 -0.092
0.204
-xxxxxxxxxxxxxxx 194.66.31.14 2 u 121 256 177 19.934 3.285
0.285
-xxxxxxxxxxxxxxx 195.66.241.2 2 u 155 256 177 13.372 -1.400
0.437
-xxxxxxxxxxxxxxx 195.66.241.2 2 u 137 256 177 13.675 -0.312
0.251
ntp_gettime() returns code 0 (OK)
time d44eb465.042cb210 Thu, Nov 15 2012 0:23:01.016, (.016307390),
maximum error 3947 us, estimated error 287 us, TAI offset 35
ntp_adjtime() returns code 0 (OK)
modes 0x0 (),
offset -116.428 us, frequency -46.406 ppm, interval 4 s,
maximum error 3947 us, estimated error 287 us,
status 0x2001 (PLL,NANO),
time constant 6, precision 0.001 us, tolerance 496 ppm,
pps frequency -46.416 ppm, stability 0.000 ppm, jitter 0.000 us,
intervals 0, jitter exceeded 0, stability exceeded 0, errors 0.
David
>
> This should suggest to you that NTDP should be run 24 hours a day, seven
> days a week. . . . .
>
> It's not always possible, but TRY!
>
>
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