@ADawg,

I would try another cable and check to see if you had any IP reservations or connection preferences set for the device.

Once your Deco system is connected to your ISP, all the remaining ethernet ports on both satellite and main nodes can be used to connect devices to the network - with no additional configuration required.

Just make sure that your network is properly configured - with one of the nodes at the head of your network managing all the network's connections.