[lug] NTP question

Nate Duehr nate at natetech.com
Mon Mar 24 09:12:43 MST 2003


Yeah, this tends to lead to the old adage... if you need to rely on it,
build it yourself.

In other words, never trust an outside source for your clock unless "clock"
is their "business" like the folks at NIST.

But if you're a service provider it's outrageous to have an NTP server
available to the "public" that's drifting like AT&T/Comcast's.  That's just
negligent, because they should have had monitoring in place to see if was
working and accurate the whole time they provided it.  When it drifted it
should have been obvious to them long before you noticed it.

When I had some GPS clocks they were self-contained units complete with
NTP -- anyone played with the serial interfaces from a GPS to NTP?  I'm
curious how simple/difficult it would be to set up with a consumer-grade GPS
for home use.... hmmm... another project for another day.

Hopefully everyone came through the snowstorm safely -- I lost a 47' X 13'
aluminum awning...

Big bang when it finally came down.  Pictures on www.natetech.com -- was
stuck in my own driveway so no way to get out to buy wood to brace it... it
took three days to collapse and we watched the whole process.  Knocked the
electrical meter off the back wall of the house when it finally came down so
we had to leave one night.  DSL and servers stayed up on the UPS but it
obviously wasn't going to last the duration of the outage, so I went
flashlight in hand to the basement and shut everything down.

I stumbled on an awning company that was just starting through their voice
messages when I called, and they came right out that evening.  They have
already cleared the debris... there are four others still on the ground in
my neighborhood.  Ouch.

Neighbors must be jumpy from the sound of crunching aluminum... the crew was
there taking mine out and throwing it on a truck and two people came out of
their houses and said... "Hey!  We heard another one fall!"  Well.... umm...
nah... just the guys tearing mine down...

Nate Duehr, nate at natetech.com

----- Original Message -----
From: "Bear Giles" <bgiles at coyotesong.com>
To: <lug at lug.boulder.co.us>
Sent: Wednesday, March 19, 2003 11:16 AM
Subject: Re: [lug] NTP question


> Sean Reifschneider wrote:
> > People are welcome to use ntp1.tummy.com and ntp2.tummy.com, of
> > course...
>
> On a related note, I noticed that my time sources have drifted
> apart by a matter of seconds.  Granted, the worst offender is
> AT&T/Comcast, and I don't recall whether they ever officially
> announced the availability of a NTP signal for customers, but
> still....  (I suspect this might be a victim of the merger - the
> stratum 1 server seems to have become nonresponsive so this server
> is free-running.)
>
> But at the same time, I noticed a significant difference between
> tummy and my colo ISP's time.  Since tummy connects to NIST I tend
> to give it a bit more weight, but the fact that there's any
> difference at all drives home the point that getting an accurate
> time is a lot more than just firing up the NTP daemon.
>
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