[ntp:questions] Re: ntpd server on Linux/Debian with SPARC Sun Blade 100

Rob van der Putten rob at sput.nl
Sat Oct 21 10:18:06 UTC 2006

Hi there

Olivier Bornet wrote:

> Thanks for the link. If setting the HZ don't resolve my problem, I will
> try to adjust the drift.

AFAIK NTP can't handle asymmetrical link speeds. So if you have a busy 
ADSL link or a SDSL link with an asymmetrical load, NTPD gets the delay 
over the line wrong.

I solved the problem with the '-x' option;

Ordinarily, if the time is to be adjusted more than 128 ms, it is 
stepped, not gradually slewed. This option forces the time to be slewed 
in all cases.
Note: Since the slew rate is limited to 0.5 ms/s, each second of 
adjustment requires an amortization interval of 2000 s. Thus an 
adjustment of many seconds can take hours or days to amortize.

At boot the clock is synced with ntpdate, so the above doesn't cause any 

There is only one good; knowledge, and one evil; ignorance (Socrates).
Virtue is more to be feared than vice, because its excesses are not 
subject to the regulation of conscience (Adam Smith).

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