[ntp:questions] ntp not updating the time

unruh unruh at wormhole.physics.ubc.ca
Wed Apr 14 01:40:07 UTC 2010


On 2010-04-14, Chuck Swiger <cswiger at mac.com> wrote:
> On Apr 13, 2010, at 4:13 PM, Marc Fromm wrote:
> [ ... ]
>> The server loses 1 second per minute.
>> I've been checking it since I manually updated the time and after 2 hours it is 2 minutes and 1 second behind.
>
>
> adjtime() used by ntpd and others typically won't correct more than about 2 seconds per hour, so, barring extreme measures, your hardware is too busted to keep reliable time.  Sorry.  :-/

adjtimex can (using the tickadjust which ntp does not use) correct up to
100000PPM ( 6 min/hr). but only it is consistant (ie it looses 6 min
every single hour). But I suspect he will find that some hours it loses
2 min, the next 1 min the next -4 min, etc. That cannot be corrected by
anything. ntpd can only correct 500PPM (that is about 1.5 sec/hr) and if
the clock frequ gets higher, it gives up and quits doing anything. 


>
>> ntpq -p produces the following:
>>     remote           refid      st t when poll reach   delay   offset  jitter
>> ==============================================================================
>> 131.107.13.100  .ACTS.           1 u  858 1024  374    4.431  62588.8 21305.0
>> *LOCAL(0)        .LOCL.          10 l   16   64  377    0.000    0.000   0.001
>> 
>> My ntp.conf file is all defaults except for the time server entry on line 13.
>
> If you add a server line, then you also need to add a restrict line like:
>
>   restrict time-nw.nist.gov
>
> ...otherwise it lacks permission to change your clock, because of the paranoid "restrict default" line.
>
> Regards,




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