[ntp:questions] Re: synchronization
ronc at depauw.edu
Fri Mar 10 16:12:54 UTC 2006
Richard B. Gilbert wrote:
> noquery, on a line by itself is invalid!!!! If it were valid, you would
> be shooting yourself in the foot because "noquery" means "do not respond
> to querys" which means your server couldn't serve time anyway!!!!
Well.. I took the "default" config file and it was in there.. so I
left it there.
>> +time-b.nist.gov .ACTS. 1 u 43 64 377 36.473 3598.51
>> *tick.usnogps.na .USNO. 1 u 50 64 377 107.202 3594.40
>> +NAVOBS1.MIT.EDU .PSC. 1 u 43 64 377 36.762 3596.60
> This is a pretty dismal looking ntpq banner!! The offsets say that your
> clock is off by more than three seconds. At the maximum slew rate of
> 500 parts per million, it will take several hours to bring your clock
> into synchronization.
yes I know.. that's why I noticed there to be a problem
> How are you starting ntpd? What options are you using? If you use the
> -g option, ntpd should set the clock unconditionally at startup; e.g. it
> should query the servers to find out what time it is and then set your
> clock to that time.
I start it with : 'service ntpd start"
That results into : ntpd -U ntp -p /var/run/ntpd.pid
> Next, the three servers you are using appear poorly chosen. You should
> not be using stratum 1 servers unless you will be serving time to
> several hundred clients! All the public stratum 1 servers are generally
> loaded to the breaking point and should be avoided if possible. The
> figures for round trip delay are quite high! 107 milliseconds is
> downright unreasonable! 36 is not very good either. The highest delay
> I have is 19 milliseonds. Look for servers closer to you; e.g. with
> shorter round trip delays.
Ok.. so how do I find different servers ?
> You should be using four servers. Four is the minimum number of servers
> required to defend against one false ticker. Two is the worst possible
> number. Three is better but if one fails. . . .
I can do that.. if I know where to find 4 decent/good servers.
> I'd suggest removing or commenting out ALL the restrict statements until
> you get everything else working. Then you can uncomment or replace them
> and see if they break anything.
I can do that.. although I don't think the restrict lines are not
breaking anything. The timeserver does "connect" but the synchronisation
is lost all the time it seems.
More information about the questions