My ISP comes with a Home Gateway along with their Broadband service, it is a Wifi Router with security protection.  My Deco is set behind as a DMZ zone behind of this ISP Router with a 192.168.xxx.xxx segment, all my other home devices under Deco Mesh system is on 192.168.yyy.yyy segment.  I then test the Port Forwarding of the Deco Mesh system by forwarding all ports to my NAS.  I disable the firewall on my NAS but nothing comes through.

I read an article in Google somewhere saying that if the WAN port is not a real IP, i.e. in a double NAT environment, Port Forwarding will not work.  I would like to confirm this and ask if there is any workaround.

Appreciate if anybody in the Community can help, thanks a lot.

Richard