Re: discovering whether the time on a host is correct (and being updated)

Subject: Re: discovering whether the time on a host is correct (and being updated)
From: Chris Heimark <email@hidden>
Date: Fri, 30 Nov 2007 11:07:35 -0500

Chris

...

time.apple.com 17.254.0.49 2 u 1474 68m 1 87.314 -0.876 0.008

The 68m is 68 minutes, the number after it is a byte in octal. This byte goes from 1 to 3 to 7 to 17 up to 377. It needs to get to 17 or 37 to get a *. At a 68 minute update this will take hours.

This is controlled by /etc/ntp.conf.

John

John:

Thanks for the explanation. So I see from below terminal output that eventually my computer goes into a state where it could theoretically be a local network source for time - assuming my computer were to host NTP services. So I get that part.

Now, getting back to my original question. If my software were to run the 'ntpq -p' command under a Cocoa NSTask and parse the results, I would certainly be able to conclude whether or not my user was:

a) utilizing "Set date & time automatically" (ntpd services);

b) whether a well known remote domain was being used (say the default apple.com);

c) whether a valid refid was present (and NOT 0.0.0.0), meaning time had been acquired AND set;

d) and by examining offset, how far off the time had been based on last reading.

Using these criteria, wouldn't I be able to conclude that time was "very likely" accurate - at least at the point in time when I conducted the test - to within seconds?

Chris

[imacg5:~] chris% ntpq -p

remote refid st t when poll reach delay offset jitter

==============================================================================

time.apple.com a17-106-100-13. 2 u 65m 68m 3 122.129 -11.398 14.722

[imacg5:~] chris% ntpq -p

remote refid st t when poll reach delay offset jitter

==============================================================================

time.apple.com 17.254.0.49 2 u 882 68m 7 88.803 9.453 20.851

[imacg5:~] chris% ntpq -p

remote refid st t when poll reach delay offset jitter

==============================================================================

time.apple.com a17-106-100-13. 2 u 384 68m 17 134.028 0.707 8.746

[imacg5:~] chris% ntpq -p

remote refid st t when poll reach delay offset jitter

==============================================================================

*time.apple.com time2.euro.appl 2 u 218 68m 37 145.257 32.584 31.877

[imacg5:~] chris%

 _______________________________________________
Do not post admin requests to the list. They will be ignored.
Macnetworkprog mailing list      (email@hidden)
Help/Unsubscribe/Update your Subscription:

This email sent to email@hidden

Follow-Ups:
- Re: discovering whether the time on a host is correct (and being updated)
  - From: Ben Artin <email@hidden>

References:
	>Re: discovering whether the time on a host is correct (and being updated) (From: Chris Heimark <email@hidden>)

Prev by Date: Re: AX.25?
Next by Date: Re: discovering whether the time on a host is correct (and being updated)
Previous by thread: Re: discovering whether the time on a host is correct (and being updated)
Next by thread: Re: discovering whether the time on a host is correct (and being updated)
Index(es):
- Date
- Thread