I am able see that nbn arris box is up however no authentication detected. see below link for checking your set up. If set up is correct then try to reset your router by pressing reset button leave modem for auto configuration for 20 minutes.
If doen't work then follow below step for manual configuration.
A. Open your browser and in the address bar type http://192.168.1.1 and press Enter.
B. Enter admin for both the username and password and click Login. If you have changed the login credentials, please enter the current username and password for your modem interface.
C. You will see the home screen shown on the right. Click the Advanced tab.
D. On the menu on the left side of the page, click Network to expand the menu and then click EWAN.
E. Enter your TPG Username and Password. Click Save