Netstat isn't what he's looking for. Netstat only tells the addys of connections with him.
The OP is looking for the cmd to sniff out / map the internal IPs on his / her network.
Personally, I would log into the router or the DHCP server and do a client list, but that option is not always available. There are ways of doing it on linux, but I'm not sure the protocol exists on Windows.