Para permitir el acceso a SQL Server mediante la intranet realizar lo siguiente:

Entrar al grupo de programas Microsoft SQL Server 2008 R2 -> Herramientas de configuración -> Administrador de configuración de SQL Server y en la seccion de Configuracion de red de la instancia de SQL Server Habilitar el protocolo TCP/IP

Posteriormente proceder con las siguientes indicaciones para la configuración del Firewall de Windows

Open the Control Panel

1. Click “System and Security” if you are in “Category” view mode.
2. Click “Windows Firewall”. (The green text)
3. Click “Advanced settings” along the left hand side.
4. Click “Inbound Rules” along the left hand side.
5. Click “New Rule…” to the right in the actions pane.
6. Ensure “Program” is selected and click “Next >”
7. Select “This program path:” radio button and click browse.
8. You need to select the sqlservr.exe file which for my 2005 instance was located “C:Program FilesMicrosoft SQL ServerMSSQL.1MSSQLBinn”
9. Click “Open”
10. Click “Next >”
11. Click “Next >” again
12. Click “Next >” again
13. Give it a name of “Sql Server 2008 R2” or another appropriate name. I would suggest giving the service name maybe. I Called it this “Sql Server: Sql2005“
14. Click “Finish”

You may need to also add the Sql Browser service so that any named instances can be found.

1. Click “New Rule…” again in the actions pane.
2. Select “Port” and click “Next >”
3. Select “UDP”
4. Select “Specific local ports” and enter the port number 1434
5. Click “Next >”
6. Click “Next >” again
7. Click “Next >” again
8. Enter a name like : “Sql Server Browser”