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I have a lot of servers syncing to the same NTP servers (4). Not every server is in the same LAN. Some are 3 hops away from the NTP servers and some are 6 hops away.

On couple of servers I see that the poll value never touches the 1024 mark and the jitter value is in double digits. Could it be due to the system hardware? These are windows servers (physical) and require as accurate time as possible. Please advice what I should do.

Some of the stats that I collected manually from the bad box (which is 6 hops away from the ntp servers)

C:\Program Files (x86)\NTP>ntpq -p -n
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
+*.*.*.25  *.*.*.233     2 u   12  128  377    1.210  -12.579  14.913
+*.*.*.26  *.*.*.233     2 u   96  128  377    1.067   -2.235   9.885
**.*.*.27  *.*.*.233     2 u   24  128  377    1.038   -7.569  11.178
+*.*.*.28  *.*.*.233     2 u   49  128  377    1.288  -11.058  14.544

     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
+*.*.*.25  *.*.*.233     2 u  124  128  377    0.614   -6.212   5.329
+*.*.*.26  *.*.*.233     2 u   93  128  377    0.910   -9.431   3.111
+*.*.*.27  *.*.*.233     2 u    1  128  377    0.824   -7.428   3.129
**.*.*.28  *.*.*.233     2 u   84  128  377    1.503   -8.230   3.511

     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
**.*.*.25  *.*.*.233     2 u  117  128  377    1.235   -4.084  11.405
+*.*.*.26  *.*.*.233     2 u   96  128  377    1.335  -11.813  13.130
+*.*.*.27  *.*.*.233     2 u  130  128  377    1.549  -14.036  16.381
-*.*.*.28  *.*.*.233     2 u   79  128  377    1.258   13.395  22.203

     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
**.*.*.25  *.*.*.233     2 u   88  128  377    1.235   -4.084  14.068
+*.*.*.26  *.*.*.233     2 u   63  128  377    1.335  -11.813  17.086
+*.*.*.27  *.*.*.233     2 u  103  128  377    1.549  -14.036  20.691
-*.*.*.28  *.*.*.233     2 u   47  128  377    1.258   13.395  20.231

     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
+*.*.*.25  *.*.*.233     2 u   47   64  377    0.652  -15.805  14.077
**.*.*.26  *.*.*.233     2 u   11   64  377    1.013  -14.423  11.375
-*.*.*.27  *.*.*.233     2 u   63   64  377    0.765   -2.030   7.680
+*.*.*.28  *.*.*.233     2 u    4   64  377    1.191  -17.980  14.393

     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
-*.*.*.25  *.*.*.233     2 u    3  128  377    1.576   18.665  21.999
+*.*.*.26  *.*.*.233     2 u   73  128  377    0.637   -5.012  14.405
**.*.*.27  *.*.*.233     2 u  127  128  377    0.272   -8.237  14.438
+*.*.*.28  *.*.*.233     2 u  123  128  377    1.190  -14.383  18.875




C:\Program Files (x86)\NTP>ntpdc -c loopinfo
offset:               -0.016430 s
frequency:            7.106 ppm
poll adjust:          18
watchdog timer:       133 s

offset:               -0.016430 s
frequency:            7.106 ppm
poll adjust:          18
watchdog timer:       341 s

offset:               -0.000149 s
frequency:            6.645 ppm
poll adjust:          0
watchdog timer:       383 s

offset:               0.015735 s
frequency:            6.725 ppm
poll adjust:          7
watchdog timer:       577 s

offset:               -0.010331 s
frequency:            6.748 ppm
poll adjust:          21
watchdog timer:       567 s

offset:               -0.009427 s
frequency:            6.687 ppm
poll adjust:          28
watchdog timer:       301 s

offset:               -0.007361 s
frequency:            6.612 ppm
poll adjust:          30
watchdog timer:       155 s

offset:               -0.008106 s
frequency:            4.358 ppm
poll adjust:          30
watchdog timer:       291 s

NTP.conf

# NTP configuration file

# Use drift file 
driftfile "C:\Program Files (x86)\NTP\ntp.drift"

# Logs
statistics loopstats peerstats clockstats
statsdir "C:\Program Files (x86)\NTP\logs\"     # directory for statistics files
filegen peerstats file peerstats type day enable
filegen loopstats file loopstats type day enable
filegen clockstats file clockstats type day enable
logfile "C:\Program Files (x86)\NTP\logs\syslog.txt"

# Use specific NTP servers
server *.*.*.25 minpoll 4 maxpoll 7 iburst
server *.*.*.26 minpoll 4 maxpoll 7 iburst
server *.*.*.27 minpoll 4 maxpoll 7 iburst
server *.*.*.28 minpoll 4 maxpoll 7 iburst
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I think I know why the value of poll is 128. The maxpoll value is set to 7 which I found out translates to 128s. –  Aseem May 28 '14 at 12:53

2 Answers 2

You are correct, when you hardcode maxpoll 7 the maximun polling interval will never rise above 128. Feel free to submit your own answer but either way please close this question.

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Thanks. I am still trying to figure out the reason for high offset value. –  Aseem May 29 '14 at 4:52
up vote 1 down vote accepted

Was not able to replace the board. Modified the config to poll frequently and that has helped.

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