What are some connection string problems that can trigger a 08001 error, and how can I fix them?

Common connection string issues include an incorrect server name or instance name, typos in the server name, and specifying the wrong port number. Double-check the server name against the SQL Server instance name. Use the correct instance name (e.g., `Server=MyServer\MyInstance;` if it's a named instance). If not using the default port, specify the port explicitly (e.g., `Server=MyServer,1434;`). Always verify the connection string's syntax.