Nagios - check_ntp_time - Offset Unknown

The key line here is this one:

discarding peer 0: stratum=0

An NTP server identifying itself as stratum 0 is a violation of the spec (it's reserved for atomic clocks or something like that). I had this problem years ago with some BSD and Mac OS X hosts. I ended up hacking the stratum check out of the source and maintaining a separate build of the plugin for "problematic" hosts.

The offending lines are 254-257 (currently, anyway), if you want to rip that out. It's a hack, but it works for me ;-)

I found this thread in the mailing list archives about it. I think there was another one where I suggested adding a command-line option to ignore the stratum check, but I don't think it got any traction.

There's also a bug report about it, but it hasn't yielded anything useful as far as I can tell.