That’s really helpful, thank you. I’ve ordered an AX23 which will arrive tomorrow. I’ll try to figure it out in the next few days and report back.

Thank you! I’ll evaluate and report back.

And openwrt is capable enough?

Yeah it’s insane right? Every address is reachable when I open a port range. And it’s like there are ~ 10 predefined services (HTTP/S, SMTP, …) and the category “All other ports” where also 22 is part of. So I really have the choice to either keep everything shut or leave everything wide open.

I think I can’t use my own modem but I’ll have to double check with my ISP. But yes the Wi-Fi is also provided by that router and it’s also quite crappy.

Thank you! Do you have an example for such a firewall device? Could something like the TP-Link Archer AX55 in IPv6 “pass-through” mode do the job? Or would you go for a standalone firewall? My budget is around a hundret bucks.