Users going directly to WebSphere, not Apache, how to prevent?

["Walden H. Leverich" <WaldenL@xxxxxxxxxxxxxxx>]

All,
 
I've got a situation where some users are going to directly to the
internal web server in WebSphere (portal) and not going through the
apache server front end to access my portal apps. I need to stop this. 
 
If I understand how the apache plug-in works, it effectively forwards
WebSphere traffic to the web server in WebSphere, but it does so
"internally." That's fine, but how do I stop users from accessing the
web server externally? In my case the WebSphere web server is running on
port 30020. 
 
And yes, I know, "there are rarely technical solutions to managerial
problems" so I should just tell the users not to go to 30020. <G>
 
-Walden