[ntp:questions] Re: simple time server

Richard B. Gilbert rgilbert88 at comcast.net
Thu Aug 3 01:49:26 UTC 2006


Bryan Henderson wrote:

>>NTP is a very poor choice for what you want to do.  It does not deal 
>>with local time at all, it's UTC all the way.
> 
> 
> When I said the server would give out local system time, I just meant
> the time from that computer's local authority (i.e. gettimeofday()) as
> opposed to something that professes to be global standard time.  I
> don't care about time zones.
> 
> 
>>Have you considered using rdate?  See man rdate.
> 
> 
> That looks pretty good.  Not as good as NTP, due to the reduced precision
> and less standard protocol, but OK.  Thanks.  It's definitely the
> _concept_ I'm looking for.
> 
> I suspect it's pretty easy just to _write_ an NTP server program that
> does what I'm describing, but I thought I should make sure it hasn't
> already been done.
> 

The NTP reference implementation, with all the libraries and accesories 
is about 75,000 lines of code.  I doubt very much that it was easy to 
write or that it would be easy to write a new one from scratch.  There 
is much, much more to NTP than "What time is it?", "It's 21:42:37.421".

If you just want to ask another system what time it is, you don't need 
ntpd.  Rdate will get you the time to the nearest second with very 
little trouble.

SNTP or Simple Network Time Protocol is much easier to implement but not 
as accurate.




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