Traffic Router returns NXDOMAIN for non-existent AAAA records within existent DNS zone for the Delivery Service

[mikeV02]

This Bug Report affects these Traffic Control components:

• Traffic Router

Current behavior:

For IPv4 only infrastructure, that is, no IPv6 anywhere more than the default link-local, Traffic Router replies NXDOMAIN for AAAA when a client issues request. Causing DNS resolvers to flush cache and mark the Delivery Service FQDN as non-existent for the TTL lifetime. This happens regardless the value of "IPv6 Routing Enabled" on the Delivery Service

Expected behavior:

Traffic Router should return NODATA (an empty NOERROR reply) instead of NXDOMAIN for non-existent AAAA records within an existent zone.

Steps to reproduce:

Do a DNS lookup for the Delivery Service for A records, NS, records, AAAA records. A and NS return valid answers, AAAA returns NXDOMAIN.