Re: ntp/ntpdate and NAT

[tlaronde%polynum.com@localhost]

On Tue, Jun 04, 2013 at 03:13:10PM +0200, Martin Husemann wrote:
> 
> If your NAT device causes persistent enough packet handling delays in the
> order of 2 seconds (or enough to make NTP erroneously drift that far),
> you have a serious problem.
>[...] 
> What timecounter source did your machine pick and what other choices do you
> have?
> 
>       sysctl kern.timecounter
> 
$ sysctl kern.timecounter
kern.timecounter.choice = TSC(q=3000, f=2594231400 Hz)
clockinterrupt(q=0, f=100 Hz) hpet0(q=2000, f=14318180 Hz)
ACPI-Fast(q=1000, f=3579545 Hz) lapic(q=-100, f=99820760 Hz)
i8254(q=100, f=1193182 Hz) dummy(q=-1000000, f=1000000 Hz)
kern.timecounter.hardware = TSC
kern.timecounter.timestepwarnings = 0

So the precision should be adequate enough (I have just switched to
hpet0 since it is here...).

But I suspect that the NAT is in cause, since it is a Windows machine,
not dedicated to the task, used for browsing the Web, directly connected
to a DSL modem (note: I has to do with it; I'm putting a NetBSD
server---for KerGIS---inside a LAN I do not own).
-- 
        Thierry Laronde <tlaronde +AT+ polynum +dot+ com>
                      http://www.kergis.com/
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