p2p set top box tracking

I was shown a demonstration of wireshark a few months ago. We were trying to trace the ip addresses and country of origin from a p2p iptv set top box. I'm not sure if he had any add ons to the wireshark software. I want to set up the same scenario. The stb was connected to the internet and to a laptop via a small 3 way switch. I've tried to set it up again but with my desktop but it's just giving me the ip addresses of my PC & the ip address of the stb. Can you point me in the right direction with which tutorials I have to read / see please. And whether I need to install any add-ons????