With Dahua POE NVR's the cameras will connect to their own internal network. The cameras (so long as they are compatible - and no not think that Onvif means compatible) aer basically plug and play which makes it, for me, very convenient and easy to setup. You can then access them as any other DVR or NVR through the unit itself.
That being said I did not see this in any other post - If you take a network cable and plug a pc into one of the NVR's POE slots you can access the cameras directly using the ip address the NVR assigns to it.
I have seen issues with NVR's that connect directly to the cameras like this where the "handshake" (for lack of a better term) can but not always change the settings on cameras, particularly with the infrared settings.
If you go to the remote device setup menu in the NVR you can see what the ip address is on each camera and access it through Chrome, Firefox, and IE. With quicktime installed on the pc you can watch the video and Chrome and Firefox do not require the Active X settings changes.