[ntp:questions] ntp clients out of sync with server

naihong at gmail.com naihong at gmail.com
Tue Oct 28 21:41:43 UTC 2008


On Oct 28, 12:21 pm, Unruh <unruh-s... at physics.ubc.ca> wrote:
> "naih... at gmail.com" <naih... at gmail.com> writes:
> >Hello,
> >I have a test environment,
> >    Server(WinXP2,Meinberg ntp-4.2.4p5)
> >                                              |
> >  ____________________________________________________
> >  |                                           |                                         |
> >C1(XP2,ntp-4.2.4p5)  C2(Vista-64,ntp-4.2.4p5)
> >C3(CentOS5.2,ntp-4.2.2p1)
> >Since it's time island, no connection to public time server. I select
> >the orphan mode. After the server and clients start up. At first, the
> >clents can sync to server's clock. But after 1 day, all 3 clients
> >begin to sync to its local clock, not the server. The output of ntpq -
> >p is,
> >    remote          refid           st  t when poll  reach    delay    offset     jitter
> >       ============================================================
> >       10.200.98.51 127.0.0.1            5 u   105  256   377
> >0.299   -1.886     0.591
> >        *LOCAL(0)           .LOCL.          12 l      23   64   377     0.000
> >0.000    0.001
> >The ntp.conf on server is,
> >driftfile "C:\Program Files\NTP\etc\ntp.drift"
> >tos orphan 5
> >The ntp.conf on all 3 clients is(except the drift file location),
> >driftfile "C:\Program Files (x86)\NTP\etc\ntp.drift"
> >server 10.200.98.51 iburst
> >server 127.127.1.0
> >fudge 127.127.1.0 stratum 12
> >logconfig = all
> >logfile "C:\Program Files (x86)\NTP\etc\ntp.log"
> >statsdir "C:\Program Files (x86)\NTP\etc\log\"
> >statistics loopstats peerstats clockstats
> >filegen loopstats file loopstats type day enable
> >filegen peerstats file peerstats type day enable
> >filegen clockstats file clockstats type day enable
> >At beginning, the configuration file on client has only first 2 lines,
> >the lines from server 127.127.1.0 were added for debugging purpose.
>
> Debugging purposes? What debugging purposes?
>
I mean from these logs, I want to find out why clients are out of sync
with server. I don't think  it is cause by server's local clock
drifting, since even I exchange server and client, out of  sync still
happens.

> >The same thing happened two years ago, on different computer hardware.
> >At that time,I select undiscipline clock on server, and want 5 clients
> >sync to server. But after days running, the clients out of sync with
> >server, chasing their own clock. So I have to disable ntpd, and add
> >ntpdate to crond to sync the time by force.
>
> And you never thought of disabling the local clock? Why?
Do you mean remove  "server 127.127.1.0" from client's configuration,
it is not in the ntp.conf at beginning. Add it just for tracing
problem purpose.


>
> >Could any one give me some clues on this issue. Thanks
>
> You stick the local clock in why? "doctor it hurts when I beat my head
> against the wall" .
> Look at the peerstats log-- are they getting any measurements from the
> proper host?
>
> What is the output of ntpq -p?
As previous message
remote          refid           st  t when poll  reach    delay
offset     jitter
============================================================
10.200.98.51 127.0.0.1 5 u   105  256   377    0.299   -1.886
0.591
*LOCAL(0)     .LOCL.    12 l      23   64   377     0.000  0.000
0.001




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