Can I scan an ad hoc network to find all the connected devices and their IP addresses?

I am trying to connect an IP Camera (with an onboard web server) to a Macbook Pro (OS 10.11). If I use a router it's very easy: they both connect to the router and then the Mac can log into the camera and see its image. I'd like to run on batteries and so I want to do away with the router. I've set up an ad hoc network with Create Network, and my IP Camera may be logging in, but I have no idea at what IP address. I've tried adr - a and ping 192.168.255.255 (because subnet mask is 255.255.0.0) but neither seem to work on an ad hoc network. Is their another builtin or add-on tool I could use? Thanks.