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Frequency of Traffic to Time Servers

I'm running Red Hat 7.3, and have NTP configured with 4 servers
currently.  I have been watching the NTP traffic as it crosses my
firewall, and I am finding that traffic to and back from each server
happens roughly once a minute.  The clock is currently off by about 16
seconds as best as I can tell.  As it drifts closer to the correct
time, will the frequency of network requests drop, or is it normal to
query NTP servers this frequently?
0
michaelb
7/10/2003 6:15:28 PM
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michaelb@logicpd.com (Michael Bendzick) wrote in message news:<6d26b1c0.0307101015.3728bfcf@posting.google.com>...
> I'm running Red Hat 7.3, and have NTP configured with 4 servers
> currently.  I have been watching the NTP traffic as it crosses my
> firewall, and I am finding that traffic to and back from each server
> happens roughly once a minute.  The clock is currently off by about 16
> seconds as best as I can tell.  As it drifts closer to the correct
> time, will the frequency of network requests drop, or is it normal to
> query NTP servers this frequently?

I'm not sure which version of ntpd is included on the Red Hat 7.3
distribution.  When the time is off by 16 seconds, it should take
about 9 hours to slew the time to within the normal NTP tolerances.  I
recommend you change the ntpd startup command line options to allow
ntpd to step the clock when it starts initially.  The option should
should be -g.

Best Wishes,


roy
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0
roy
7/10/2003 11:10:20 PM

Roy wrote:
> michaelb@logicpd.com (Michael Bendzick) wrote in message 
> news:<6d26b1c0.0307101015.3728bfcf@posting.google.com>...
> 
>> I'm running Red Hat 7.3, and have NTP configured with 4 servers currently. 
>> I have been watching the NTP traffic as it crosses my firewall, and I am 
>> finding that traffic to and back from each server happens roughly once a 
>> minute.  The clock is currently off by about 16 seconds as best as I can 
>> tell.  As it drifts closer to the correct time, will the frequency of 
>> network requests drop, or is it normal to query NTP servers this 
>> frequently?

You can regulate this with maxpoll and minpoll server options, however after
the start ntpd will poll the servers every 64 seconds and slow down to 1024
seconds continously.

>>> http://www.eecis.udel.edu/~mills/ntp/html/confopt.html

minpoll minpoll
maxpoll maxpoll
	These options specify the minimum and maximum poll intervals for NTP
	messages, in seconds as a power of two. The maximum poll interval
	defaults to 10 (1,024 s), but can be increased by the maxpoll option to 	
	an upper limit of 17 (36.4 h). The minimum poll interval defaults to 6
	(64 s), but can be decreased by the minpoll option to a lower limit of 4
	(16 s).

Regards,

Edin


> 
> 
> I'm not sure which version of ntpd is included on the Red Hat 7.3 
> distribution.  When the time is off by 16 seconds, it should take about 9 
> hours to slew the time to within the normal NTP tolerances.  I recommend you 
> change the ntpd startup command line options to allow ntpd to step the clock 
> when it starts initially.  The option should should be -g.
> 
> Best Wishes,
> 
> 
> roy

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0
Edin
7/11/2003 8:37:47 AM
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