Once you select a server machine, you need to add a database server registration for each of the runtime servers to which you want to add databases.
To add a database server registration, perform the following:
Right-click the required server node, and select All Tasks > Register Database Server.
The Register DB Server dialog box is displayed.
In the DBMS registration alias name field, enter a new name to identify the database server registration.
In the Server machine field, enter the name of the database server. If the database server is local, enter localhost. Otherwise, enter the remote database server name. If the database server is in a cluster, enter the database cluster name.
In the Instance name field, enter the SQL Server instance name if you are using a named instance. If the SQL Server instance on the database server is the default instance, leave this field blank.
Click OK to add the database server registration node to the runtime server node.