I would create or Edit an Event Report and base it on the Event Type for Node Down and Event Type for Node Up.
What I did was create and edit a copy of Last 250 Events Web-Based.
Under content you should see All Event, select Edit.
Change Where At least one child condition must be satisfied OR
Select Add Condition, and select Event Type is Equal to Node Down
Select Add Condition, and select Event Type is Equal to Node Up
Select Add Layout
You may want to Edit the Table to Group Results By Node.