mmon and other housekeepingI think that also if the the database instance isn't idle, it shouldn't open ports to the outside.
But that will also break Apex, the 8080 web pages won't workRestricting the apex to locahost and made it available trough apache (proxy) in a restricted area was easy, but finding out what's going on with these two ports/processes is awkward.
or notification servicesI have the change notification privilege activated for some users, but I would wonder if there's a listening tcp port for this.
i.e. save the dispatchers and shared_servers parameters setting to enable it later ...can be removed by clearing the Dispatchers parameter