An FYI for someone who may stumble in looking for the same answer: CP -> Membership -> Member Management -> Ban Lists Tab -> Banned IP Addresses section
IP's can be banned as a full segment (Class D): 192.168.1.1
And IPs can be banned as any other class as: 192.168.1.% 192.168.%
Additionally, email bans can be conducted much the same way and in the same section.
