I have a ArcGIS Server 10.6.1 setup on Windows server 2012 64 bit. Some times in a day, we gate ARcGIS Server log as "The machine 'xx.xx.xx.xxx' was not reachable while performing this operation. The server machine will be notified of this change when it comes back online. If ArcGIS Server is going to continue to be unavailable, remove the machine from the site."
I am not able to understand what is happening at the Site level.. HAs any one faced same issue? if Solved how?