[sweetjuly]

IP blocks also just don't work on IPv6. Unless you're prepared to block entire by ASN, an adversary can cheaply just buy up a lot of address space and churn through them. It gets even messier when dealing with real ISP networks because some hand out /40s for residential customers whereas others give just a /56.

[nerdbert]

I'm sure you can buy a table that says what size subnet to block for various ipv6 ranges.