<iisnode enableXFF="true" />
I was trying to blacklist a block of IPv6 adresses (an IPv6 prefix actually) but that results in a 'rule is invalid' message when I try to enter something like:
Hm, that surprising, but I suppose blocking of IPv6 isn't as thoroughly tested... however according to this site, the range you supplied isn't valid
It's not an IPv6 address, it's a block of IPs in CIDR notation:
Blocking a single IPv6 address isn't very effective.