In the section "Preparing to Debug", Chapter 21, you are directed to use the db2dbugd command. This is incorrect. Instead, use the following command:
idebug -qdaemon -quiport=portno
The default port number is 8000. idebug is a client-side daemon of the IBM Distributed Debugger, and ships with VisualAge for Java, and WebSphere Studio Application Developer.