[ntp:questions] Re: Two clocks?

Richard B. Gilbert rgilbert88 at comcast.net
Tue Nov 16 06:18:07 UTC 2004

Harlan Stenn wrote:

>I'd be inclined to connect them to different machines (and have them peer
>with each other) so in case one of them went down you'd have the other
>up and still serving time to the rest of your network.
That was my first thought.  I raised the question after actually trying 
it.  I started with machine "sunblok" configured with the Motorola M12+T 
GPS receiver and all the servers, good and not so good, in the "greater 
New Jersey" area.  That gives me five networks servers plus the 
reference clock and peering with the second machine, "sunburn".

Today I configured Sunburn with the Traconex and peered with sunblok.  I 
didn't want to tap any of my network servers a second time since they 
are all busy and some appear to be staggering.  Sunburn is running ntp 
4.2.0a at 1.122.  I saw a situation earlier today where both the refclock 
and the peer were "insane":

ntpq> peer
     remote           refid      st t when poll reach   delay   offset  
xWWV_PST(0)      .WWV.            0 l   52   64  377    0.000   67.135   
xsunblok         .GPS.            1 u  947 1024  377    0.518  -59.704   

As someone here remarked recently, two is the worst possible number of 
servers!  With my "godlike" view of the matter, I can safely say that 
the WWV receiver is probably having the problems and that sunblok should 
be believed.  I can say that because I know from several months of 
experience that when sunblok is synched with GPS it generally has an 
offset of less than one millisecond.  ntpd on sunburn has no way to 
figure that out.

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