How to connect to a DB2 database? There is no database alias in the connection window.
The connection is not yet configured.
Configure DB2 client connection first so the alias in the connection window will be populated. Ensure that there is network connection between the client machine where Toad for DB2 is installed and the server where the DB2 database is installed. The alias is defined when you cataloged or configured the DB2 database or subsystem on the Toad DB2 client.
See attached document for configuring Toad for DB2 client connections.
You can also search the help file within Toad for DB2. Click Help from the menu and search anything you want to know about Toad for DB2.