Nagios check_ntp quits working in 2009 with Offset unknown

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Nagios check_ntp quits working in 2009 with Offset unknown

Posted by Admin • Friday, January 2. 2009 • Category: Code and Hacks

I've been happily using nagios to monitor all my servers for quite some time, yet two days ago, suddenly, I started getting "Offset unknown" from my check_ntp check. Same from check_ntp_time. Then it was intermittent, service was flapping (going in and out of Unknown state). I messed around with ntp.conf and changed servers, restarted ntpd and then it stopped working across the board...

asterisk asterisk # /usr/nagios/libexec/check_ntp_time -H srv
NTP CRITICAL: Offset unknown|

The problem?

Apparently a leap year second is inserted periodically, and that's what was done on Dec 31 2008! Just one second, but enough to expose a bug in nagios-plugins-1.4.11

Running with -v got me this:

# /usr/nagios/libexec/check_ntp_time -H server -v
sending request to peer 0
response from peer 0: offset 0.01255832968
sending request to peer 0
response from peer 0: offset 0.01255403762
sending request to peer 0
response from peer 0: offset 0.01255219412
sending request to peer 0
response from peer 0: offset 0.01255332731
discarding peer id 0: flags=1
overall average offset: 0
NTP CRITICAL: Offset unknown|

The solution?

The bug was already fixed in 1.4.13 - so just upgrade. In my case (Gentoo) - that version is still ~x86 (unstable), but I'm upgrading anyway.

I installed 1.4.13, and now I get this:

# /usr/nagios/libexec/check_ntp -H asterisk   
NTP OK: Offset -0.004825386102 secs|offset=-0.004825s;60.000000;120.000000;

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Michal Bryxi on 2011-05-14 05:36:
Unfortunately I have nagios-plugins version 1.4.15 and I'm still encountering this problem:

watch01:~ # /usr/lib/nagios/plugins/check_ntp_time -H lb01 -w 1 -c 2 -v --version
check_ntp_time v1.4.15 (nagios-plugins 1.4.15)
watch01:~ # /usr/lib/nagios/plugins/check_ntp_time -H lb01 -w 1 -c 2 -v
sending request to peer 0
response from peer 0: offset 0.07509887218
sending request to peer 0
response from peer 0: offset 0.07508444786
sending request to peer 0
response from peer 0: offset 0.07499825954
sending request to peer 0
response from peer 0: offset 0.07510817051
discarding peer 0: stratum=0
overall average offset: 0
NTP CRITICAL: Offset unknown|
dave on 2012-05-31 21:59:
I just had this problem on an old Ubuntu 8.04 host. This was resolved by upgrading nagios-nrpe-plugin from 2.8.1-1 to 2.8.1-1ubuntu0.2.

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