How to set up alert for loss of communication with devices or logs no longer being connected?

[Samantha]

I need to configure Splunk Enterprise using the reporting and notification tools to create a report with notification of the following events:

Loss of communication with hosts and devices

Logs no longer being collected.

How would I go about crafting a search for these requirements? 

[richgalloway]

Finding something that is not there is not Splunk's strong suit.  See this blog entry for a good write-up on it.

https://www.duanewaddle.com/proving-a-negative/

There are apps that can help, however.  Check splunkbase for TrackMe and Meta Woot!