Cannot get computer clock to tell correct time

tfg99 · 10-02-2018, 03:41 PM

Quote:

Originally Posted by michaelk

The -q just queries the server but does not actually set the clock and was just for testing ntp. If you run the command as root it will update the system clock but ntp needs to be stopped first.

Code:

 ntpdate 137.78.0.117

The offset is the time difference between the two computers.

Okay, I'm confused. (Sorry!) 'ntpdate -q 137.78.0.117' shows the time difference between my computer and the server? If that's true, then the offset of 207 seconds means 137.78.0.117 is keeping the correct time. But that's the server that has been selected to use with NTP, so if the server is keeping the right time, why doesn't it update my computer clock?

Sorry if I'm being dumb and missing something obvious. At first I thought the server was rubbish, but now it seems like it's actually keeping the correct time???

Jack

michaelk · 10-02-2018, 03:52 PM

Like I said ntp is complicated. Correct time and quality or two different things. One reason your computer is not using the server is due to the high jitter value.

Quote:

When repeatedly reading the time, the difference may vary almost randomly. The difference of these differences (second derivation) is called jitter.

http://www.ntp.org/ntpfaq/NTP-s-sw-clocks-quality.htm

bradvan · 10-10-2018, 09:30 AM

You might want to review RHEL 7 NTP Config. Red Hat has lots of good documentation. Make sure "iburst" is at the end of your server lines in /etc/ntp.conf. That helps to ensure a quicker synchronization if the time is off by a lot.