To cut to the chase, plug your laptop with an Ethernet port with a patch cable directly into the NVR. Disable your wireless NIC in the OS. Statically, set the IP address of the Ethernet port of the laptop to the same subnet as what you think the NVR is configured. Now attempt to do a ping test on the IP addresses you think the NVR is configured for. This eliminates everything in the network path and goes straight to the NVR to determine if the NVR is actually talking on the network.