[ntp:questions] Re: SNTP Client/Server questions

Richard B. Gilbert rgilbert88 at comcast.net
Wed Aug 16 17:52:57 UTC 2006

david.lindauer at honeywell.com wrote:
> Harlan Stenn wrote:
>>>>>In article <1155648559.784059.118920 at 75g2000cwc.googlegroups.com>, david.lindauer at honeywell.com writes:
>>david> Also, assuming an SNTP client is doing similar to the spec and
>>david> aliasing the server time with a calculated propagation delay, and
>>david> assuming a LAN rather than the internet at large, can anyone give a
>>david> general feel for how far off the client is going to be from its
>>david> server?
>>It depends on how good the system clock is and how often sntp polls.
> thanks.  We aren't looking for performance extremes...  Would it be
> reasonable to get an accuracy within several seconds, feeding sntp
> clients on a lan from an sntp server which itself was fed from an NTP
> server on the net?  Assuming a local clock which is nominally 60 ticks
> per second?  And assuming the polls on both ends could be done often
> enough to account for local clock drifts?
> and thanks for the updated RFC...

W32TIME is good enough to keep things synched up within a second or two. 
   That's good enough for many applications. It seems to query a server 
somewhere between once an hour and once a week and does not place a 
heavy load on a server.  If it meets your requirements, you don't need 
to do more.

Using an SNTP client as a server is not recommended but if it works for 
you, use it.  If you have doubts, it's not terribly difficult to set up 
a true NTP server although I've never done it on Windoze.  I have a Sun 
Solaris system in that role.

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