IP Filters are used in Traffic Director and you can apply to your records that if a user meets the requirement(s) of the filter, they will be answered with that record. Otherwise, they will be answered with the World/Default. Filters can be created for: regions, countries, cities, ASN (Autonomous System Network) of the resolving name server, /24 IPv4 EDNS client subnet, and /120 IPv6 EDNS client subnet.