Re: [PLUG] Quick & Dirty NTP monitoring

[JP Vossen <jp@jpsdomain.org>]

On 01/07/2014 06:52 AM, Jeremy Kister wrote:
> On 1/4/2014 3:51 PM, JP Vossen wrote:
> > So...  Anyone have a better quick & dirty method for this?  And if not,
> > steal this one...
>
> If your ntp server can't sync time, your test is actually doing it's job
> by crying.  You can add some retries in there if you can't get the core
> issue solved.

Well, yes and no.  My original test was creating false positive email 
alerts.  My new test stopped that, but in general I dislike seeing lots 
of timeouts.  I think the root cause it folks locking NTP servers down 
after the attacked (which is overall a good thing).

The overall goal is just an out-of-band sanity check that NTP really is 
working across my network.  This came out of some issues years ago with 
firewall rules (lack thereof), down daemons, etc.


> I can't say better, but i'd use some perl to actually query the ntp. You
> can jam it all on one line easily.
>
> perl -MNet::NTP -e '
> for($i; $i<3; $i++){
>   %r=get_ntp_response("127.0.0.1");
>   if( $r{Stratum} <= 4 && $r{"Receive Timestamp"} >= time()-600 ){
>    $s=1;
>    last;
>   }
>   sleep 60;
> }
> print "error with ntp server\n" unless $s;'

I'd need to install 'libnet-ntp-perl' for that to work on my various 
Debuntu machines, and I'm not sure it gains me much more than this:
	ntptrace 2> /dev/null | head -n1 | perl -ne 'm/^[\w.]+: stratum (\d+),/ 
or next; print qq(NTP not in sync: $_) if ( $1 > 5 );'

(Note 'ntptrace' comes with NTP and is Perl without Net::NTP.)

Am I missing something?

Thanks for thinking about it,
JP
----------------------------|:::======|-------------------------------
JP Vossen, CISSP            |:::======|      http://bashcookbook.com/
My Account, My Opinions     |=========|      http://www.jpsdomain.org/
----------------------------|=========|-------------------------------
"Microsoft Tax" = the additional hardware & yearly fees for the add-on
software required to protect Windows from its own poorly designed and
implemented self, while the overhead incidentally flattens Moore's Law.
___________________________________________________________________________
Philadelphia Linux Users Group         --        http://www.phillylinux.org
Announcements - http://lists.phillylinux.org/mailman/listinfo/plug-announce
General Discussion  --   http://lists.phillylinux.org/mailman/listinfo/plug