[ntp:questions] ntpd on dial up machine: no DNS resolving => giving up on all servers

David Lord snews at lordynet.org
Sun Jun 7 10:28:06 UTC 2009

Arno Wald wrote:
> Richard B. Gilbert wrote:
>> If you need to SET the time, do it before starting anything else.
> Yes, ok. But in my configuration this is a problem.
>> Also, keep in mind that NTPD can need many hours to set both phase
>> (time) and frequency accurately!  It works best if you run it 24x365.
>> Once set, NTPD should maintain the correct time.  Some sites, for one
>> reason or another, cannot run 24x365.  If this is the case with your
>> site you should investigate tools other than NTP.
> Ok. I have found the tool "chrony", which seems to be a good solution, as 
> long as the PC-clock is not jumping around (perhaps because of an empty 
> BIOS-battery, etc.) but always is running wrong for the same amount of time. 
> This tool learns about the usual speed of the clock and corrects it, even if 
> the PC is offline. So I hope not to have big time differences anymore, so 
> that the time can be corrected in small adjustments always.

I used chrony on dial-on-demand firewalls (486 running NetBSD). Some of
chrony features weren't supported by NetBSD so I had two of these 
running 24/7 and they just worked. Somewhere I still have the stats as
to offsets but best I can remember is they were more consistent than I 
get now with always-on adsl broadband and ntpd (due I guess to 
assymetric connection badly affected by heavy load). As already 
suggested, a gps or radioclock is best solution, that's what I'm
going for, once I can work out getting good signals into my
'Faraday Cage' of a house surrounded by hills. :-)


> Thanks,
> Arno

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