Hi,
I'm looking for a way to prevent clients connect to database using CLP .
I want to allow them to connect only through a particular application.
Is it possible to define a trigger like after logon on oracle ?
Is there another way to do this?

You might be able to use Workload Manager for that.

you can write a script in shell / awk which will find out the applications which are connected to the system using CLP and then force / terminate them off. Schedule that script to run after an interval suitable for your environment.

Starting in DB2 9.7 Fixpack 3, you can specify a stored procedure in the database configuration that will be executed each time an application connects to the database. You could probably put some code in the connect stored procedure that will do what you want.
IBM DB2 9.7 for Linux, UNIX and Windows Information Center

Make certain that you Grant EXECUTE privilege to PUBLIC for the connect procedure that you specify.

Thank you about the solution, I wil try it .
We are thinking about upgrade the db to v9.7 (from 9.5) , so it will be usefull for us.