internet router & optus cable setup

[gas55au]

Hi, I have just bought a Dlink DI-804 Internet Router and I am trying to setup the router with my optus cable connection. I am able to connect to the router via http: and run the DLink setup program. On the internet settings page there is an entry under Dynamic IP of a MAC address listing 00:05:67..... I have entered the Optus Computer Name CO....... and all the other settings I have left as default. Do I need to change the MAC address and if so how (I have tried using the "Specify a MAC address" and entering the MAC address of the USB ethernet adapter but it keeps resetting it back to the above. Do OPTUS need to be given the new MAC address and they make the change at their end?????
Thanks Glenn.

[sm8000]

I bet that router uses MAC address authentication, my DI-704P does. However, if your ISP does as well, then you may need to call them. They probably won't help you set up your router since ISPs typically don't support home networking, but if they tell you that they do use MAC address authentication and you tell them you are using a router they'll probably at least help by by allowing the router to be your primary connection.