If there are routers between the cameras and the NVR, the routers must be configured to allow mDNS multicast packets between the camera network and the NVR network in order for the NVR to automatically discover the cameras. Once the cameras are discovered, you can leave the address mode as DHCP or change it to static.

If the routers are not configured to pass the mDNS packets, the cameras can be configured manually by selecting the static address mode on the camera configuration page.