If ChinaDNS received an AAAA record, drop if it's from China DNS server and pass if not so that users won't get a poisoned AAAA record.
This strategy may be very useful for users of IPv6 (like CERNET2) if their IPv6 network has higher priority than IPv4.
If ChinaDNS received an AAAA record, drop if it's from China DNS server and pass if not so that users won't get a poisoned AAAA record. This strategy may be very useful for users of IPv6 (like CERNET2) if their IPv6 network has higher priority than IPv4.