Eugene Smiley on 24 Mar 2008 15:06:37 -0700

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Re: [PLUG] NTP process FYI

JP Vossen wrote:
> I have a local NTP server synced to [0123]  I keep an 
> eye on it via a trivial cron job [1].  
> [1] Trivial NTP health; alert if localhost stratum > 2:
> 25 * * * * ntptrace | head -n1 | perl -ne 'm/^[\w.]+: stratum (\d+),/ or 
> next; print qq(NTP not in sync: $_) if ( $1 > 2 );'

I'm not sure why it's helpful to know if the NTP server is greater than stratum 
2. The pool monitoring routine makes sure that all pool servers are within 100ms 
accuracy regardless of stratum. If you need better than 100ms accuracy, the NTP 
Pool list recommends establishing your own ST1 server.

Basically what you are doing is no different than what the people who are 
pummeling the ST1 servers are doing. You are cherry picking the 'better' 
servers. This is not 'nice' behavior.

A better way of managing your NTP.conf is to connect to network-wise closer NTP 
servers. On Comcast in Philly, I could get 10 servers within 30ms delay all 
within 10ms offset. In Broward on Comcast, I'm lucky to find 10 servers within 
60ms delay within 10ms offset. Stratum is irrelevant, especially since I know of 
ST1 servers that are way off.
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