All ports are closed, even though I forwarded them on both my modem and router

Question

I wanted to open a certain port, but it didn't work. I portforwarded it on my Archer c5 router and on my Thomson TG789vn, but ping.eu still says it's closed... I did a port scan with nmap and it turns out ALL my ports are closed.. can anyone help?

Answer 1

If you're forwarding on two devices you have double NAT and no forwards can work properly.

Bridge the thompson and let the C5 route properly.