I have modem/router from Comcast and per some diagnostic tools that Comcast modem/router is creating what is called "Double nat". I don't want to replace modem/router, don't want to put it in a bridge mode and use my router. I was wondering if I can KEEP SAME configuration and buy software that can enable port forwarding in such case so application on my iphone can reach local device attached to my LAN. Is there such a software that you tried and you are sure it works when issue with double nat is present? thanks!