ns2.knowledgistics.com has no AAAA records.
Question and response
Question
dig ns2.knowledgistics.com. AAAA
Answer
ns2.knowledgistics.com. 5 CNAME knowledgistics.com.
Authority
knowledgistics.com. 2373 SOA dns.knowledgistics.com. hostmaster.knowledgistics.com. 1273459155 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0