Your 2,4 and 2,5 GHz WiFis are not seperated though also your router probably won't support NAT Loop-back so even if your ports are forwarded, any attempt at using the Plutonium Friends list or your external IP probably won't work. You can however use the IPv4 in your LAN. Open a Windows cmd window and use ipconfig to see the local IP address and use that to connect from the other PC.