[ntp:questions] NTP will fail once a week

Alain alainm at pobox.com
Wed Feb 16 21:14:52 UTC 2005



Richard B. Gilbert escreveu:
> You appear to have seven reachable network servers.   The round trip 
> delays range from a minimum of 195 milliseconds to two and a half 
> seconds!!!   Not good!!!!
> 
> Select servers near to you (low round trip delay).   The error is 
> bounded by the round trip delay; the maximum error in transmitting the 
> server's time to your system cannot be more than +/- one half the round 
> trip delay.   With a round trip delay of 2.5 seconds (2516.67 
> milliseconds) you might just as well use a cheap wrist watch as go to 
> all the trouble of running NTP.   If you are in New York, servers in Los 
> Angeles, Brazil, or Tokyo are not likely to be very good choices; 
> instead consider servers in New York, New Jersey, Pennsylvania and 
> Massachusetts.

I am in Brazil. The 2.5 seconds delays are from all but one from all the 
stratum 2 servers in Brazil as of 
http://ntp.isc.org/bin/view/Servers/StratumTwoTimeServers, I just kept 
them on the list in hope that some day they will get better. I am 
relying in NTP dismissing them. Next closer is in the US because most 
internation links

> The * in the first column indicates the currently selected 
> synchronization source.   The + in the first column designates 
> additional servers that are available as an "advisory committee".  An 
> "x" in the first column is a designation of "insanity".   A - in the 
> first column designates servers not considered hopelessly insane but 
> still not good enough to have their opinions considered at the moment.

This is usefull information, thanks

Alain



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