I have set up email notifications to alert me when node status is not up. It has been working fine until recently when I started getting alerts that say that the Node, Interface, or Application status is Unknown. Sometimes it says that the Node status is Warning too.
This wasn't the case at first as it used to reflect the actual status, now I do not understand what Unknown is, is it down or is it unreachable, will it turn to down? What is Warning, what is the difference between Warning and Down, and why did it suddenly started sending Warning alerts instead of Down?
If anyone has gone through this before I would be delighted with his support.