For the very first time i tried to selfhost a static site (lighttpd + duckdns) but I’ve failed… Is it even possible to selfhost a static site from “router 2” while i’m behind two routers? “Router 1” is from ISP and i have no possibility to change any settings except subnet, standard gateway, dhcp on/off and DMZ. -> no port forwarding. "Router 2 is Asus with port-forwarding available and i’m using an OpenVPN configuration on it (if that matters). DuckDNS could see the external ip from R2, but i couldn’t access it.
Hey, I’m doing this now, using DuckDNS. But I had to forward a port thru Router 1, as you call it. That’s your problem.
Maybe Tailscale would help you? (I’ve not used it though)
Or, instead of allowing port 80/443 traffic in, what I have is a random port used by my Wireguard VPN opened only. But I have to connect thru that when I’m not at home. I. E. only I can access my web server.