I said IP address when I meant Port address. Change the port address. 

The Firewall settings are under the system preferences. You simply add an exception and name it "Carrara". It should have the same Port setting as your render node. 

Carrara has it's own runtime for content that ships with the program. Carrara allows you to  import/use multiple runtimes from within the browser tray (I have 5) This is much nicer than only having access to the one Poser runtime.