Posted in December of course, after re-enabling IPv4 and restoring their internet connection to a functional state cuz some mystery process didn't respond all month.
Edit: I actually can't even access the link at the moment, maybe they forgot and left some IPv6 task enabled.
The challenge didn't ask to disable ipv4 but it was (jokingly) daring people to expose all ports to public to see how long the system would last before being exploited by bots. It wasn't meant to be taken seriously 😆
You can essentially achieve this with some routers with a "DMZ" network segment/ device, so all incoming requests to your external IP get forwarded to it automatically. You don't even need to disable NAT if you set it up well.
Migrating all my IPv4 stuff (firewalls, VPN, routing tables, etc) to IPv6 is probably the one thing I've procrastinated for the most time in my life :/
I'd like to migrate to IPV6 but German ISPs rotate IPV6 addresses as well (for some reason) and my domain provider (Namecheap) only supports DynDNS for IPV4 😕