IIS 8 sql server provider: Named Pipes Provider, error: 40

Today I'm trying to host my web site on IIS 8, this web site is developed in .Net MVC. When I'm trying to do a query to SQL server, hosted in another server in my intranet, I have this error message: provider: Named Pipes Provider, error: 40, but if I host my web site on IISExpress(native in Visual Studio), or I do a query from SQL server managemet, all work fine. I use this string connection:

Data Source=serversql;Initial Catalog=HD;Persist Security Info=True;User ID=sa;Password=*******

serversql is an alias that points to SQL server hosted in another machine. I have set up it in this way: 

 cliconfg set up Image