Comment by redox99

It was doomed the moment you had to maintain two separate stacks, each with its own address, firewall rules and so on.

It should have been ipv4 with extra optional bits, so you could have the same rules and everything for both stacks.

I turn it off because it's a risk having one of either stacks malconfigured.

IPv6 should've been a superset of IPv4, as in addresses are shared, not that you have a separate IPv4 and IPv6 address for your server.