You can run Wireshark on that network and see the traffic from any/all IPs on it. A port sniffer program will allow you to obtain a list of every IP and their open ports on a given network.
Of course, you can always log into your router and look at the table as well.
Looking in BI might help, but I recently had an issue where either the camera or BI reverted back to an old IP. Not sure what happened with that but using the manufacturers software, I was able to identify the camera and IP.