Aaron Bertrand has started a new series:
This is the first in a series of articles meant to provide practical solutions to common issues. In this post, we’ll talk about one of the most pervasive error messages out there:
A network-related or instance-specific error occurred while establishing a connection to SQL Server. Verify that the instance name is correct and that SQL Server is configured to allow remote connections.
Read on to see what a variety of potential solutions to this problem. I was going to joke “It’s always DNS” but Aaron actually has a section on DNS in there.