Ban: Support IPv6 ranges
Suggested by @klausenbusk
Ban is quite inflexible in that we only check one specific IP address.
With the introduction of IPv6, it's a lot easier for individuals to swap to different IP addresses in their blocks.
We'd like to come up with a way to reduce the amount of ban evasion via IP swap, if possible.
https://datatracker.ietf.org/doc/html/rfc6177
Decision: Alright. As per a middle ground between /64 and /48, /56 should cover the majority of cases -- many ISPs lease out /56 blocks, and the possibility that we hit false bans is just something that we'll have to live with; it's something we'd still have to live with in the IPv4 world as well.
Thanks, @klausenbusk, for all of your input & help with the topic. Very appreciated.