[ntp:questions] configuring clients to NTP servers

Richard B. gilbert rgilbert88 at comcast.net
Wed Mar 7 16:03:35 UTC 2007


RICCARDO wrote:
> I have 15 clients in my lan, it's correct to insert as first entry in
> ntp configuration the same server on all 15 clients ?
> 
> case 1:
> client K1,K2,K3,...K15 :
> server time.ien.it
> server ntp2.ien.it
> server ntp1.ien.it
> 
> case 2:
> 
> client K1
> server time.ien.it
> server ntp2.ien.it
> server ntp1.ien.it
> 
> client K2
> server ntp1.ien.it
> server time.ien.it
> server ntp2.ien.it
> 
> client K3
> server ntp2.ien.it
> server time.ien.it
> server ntp1.ien.it
> 
> In "case 2" clients time is get from different servers, so client
> times can be different (also if for few millisends ) It's right ?
> 

All these configurations should yield approximately the same time. 
Since I'm not supposed to use html in a newsgroup, please put the word 
"approximately" in bold face italic!

It doesn't matter what order you list the servers in if they are the 
same servers.

FWIW, you should use a minimum of four servers for reliability.  If any 
one of your three configured servers fails, you have only two left and 
it is written that a man with two clocks can never be certain what time 
it is!

There will be small differences in time between the clients.  This is 
unavoidable because they are all slightly different even if they are the 
same model hardware, running the same applications with the same 
workload.  I would expect the differences between any two randomly 
selected clients to be between one and five milliseconds.

I would suggest setting up an internal server to query the internet 
servers and serve time to your local clients.




More information about the questions mailing list