These last weeks we got several cases that our customers reported the following error message: Login timeout expired - A network-related or instance-specific error has occurred while establishing a connection to SQL Server. Server is not found or not accessible. Check if instance name is correct and if SQL Server is configured to allow remote connections. For more information see SQL Server Books Online. TCP Provider: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond, in the following video I would like to share with you what is the issue, how to identify, fix and prevent it.