Welcome to the forum and sorry to hear you're having trouble with your nVidia stream.
In answer to your question, the hub is a fairly basic get-you-going device and setting DNS is a more advanced feature the hub isn't capable of. For more advanced networking I'd suggest getting your own router and using it with the hub in modem mode.
As to using the stream through the hub, you've already tried forwarding the ports, had you turned off UPnP? Also both devices need to be on the same network so no guest networks and not one on 2.4 and the other 5GHz.