I have a ZTE MC801 router with Three's 5g home broadband. I was recently attempting to allow external access to a service on my LAN, and noticed that it was already accessible over IPv6. After some investigating, I checked with a port scanner and it turned out that all devices on my network appeared to be fully accessible externally using their IPv6 addresses.
Looking at the router's firewall settings, filtering was turned off. At this point I reset the router to factory settings, thinking I may have previously messed something up - no dice. Filtering remained off and I could still access everything externally. It is very surprising to me that this is the default setting.
I attempted to enable it manually and played with the settings. Unfortunately I can't work out how to block incoming connections. If I set it to drop by default, it seems to drop everything including outbound traffic, so I can't access the internet. How can I configure it to allow outbound traffic and block incoming traffic?
