I have a config script that is configuring the ntp server of a machine (which is running Ubuntu 14.04) by stripping lines matching ^server .* from /etc/ntp.conf and adding a new line server new.ntp.address. Now I want to test that this change is valid and working.

My initial thought was to have new.ntp.address be my desktop (which is running ntp) and set my desktop's time to something new, but after some reading I noticed that ntp will reject all but slight changes to the current time. How can I verify that my change to the ntp server config is correct and working?

Per this question, I ran sudo ntpdate -dv <my ip address> from the client machine I was configuring. The output showed it did not find an npt server because the strata was too high:

$ sudo ntpdate -dv
23 Sep 16:30:37 ntpdate[26673]: ntpdate 4.2.6p5@1.2349-o Wed Oct  9 19:08:07 UTC 2013 (1)
Looking for host and service ntp
host found :
receive( Server dropped: strata too high
server, port 123
stratum 16, precision -23, leap 11, trust 000
refid [], delay 0.02586, dispersion 0.00011
transmitted 4, in filter 4
reference time:    00000000.00000000  Sun, Dec 31 1899 16:00:00.000
originate timestamp: d7cc8124.166c9d3f  Tue, Sep 23 2014 16:30:44.087
transmit timestamp:  d7cc8124.16e4ba7a  Tue, Sep 23 2014 16:30:44.089
filter delay:  0.02586  0.02736  0.02599  0.02586 
         0.00000  0.00000  0.00000  0.00000 
filter offset: -0.00204 -0.00129 -0.00211 -0.00204
         0.000000 0.000000 0.000000 0.000000
delay 0.02586, dispersion 0.00011
offset -0.002042

23 Sep 16:30:44 ntpdate[26673]: no server suitable for synchronization found

EDIT1: I used these instructions to fudge the strata on my desktop, which is acting as the ntp server. Now, when I run sudo ntpdate <my ntp server address> from the client machine it updates its time (in my case I had to set a fairly small but noticeable change to the server time to witness this working, about 55 seconds skew is what I introduced on my desktop). However, when I start ntp on the client again and try to see it automatically pick up the changes, I'm unable to see it adjust the clock time even though I waited several minutes after starting ntp (it seemed from googling that the standard polling frequency is 60 seconds). How can I troubleshoot this?

EDIT2: Eventually the clocks did synchronize, but it took significantly longer than a minute. I think this suffices to verify my experiment, but I'm still interested in if there is a better way.


The commands ntpstat and ntpq -p off-hand

(from mobile so without sample output for now)

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