71.64-79.218.36.138.in-addr.arpa has no NS records.
NS records for this zone are defined at 64-79.218.36.138.in-addr.arpa.
NS records for this zone are defined at 64-79.218.36.138.in-addr.arpa.
Question and response
Question
dig 71.64-79.218.36.138.in-addr.arpa. NS
Answer
The response has no answer records.
Authority
64-79.218.36.138.in-addr.arpa. 900 SOA ns-1701.awsdns-20.co.uk. awsdns-hostmaster.amazon.com. 1 7200 900 1209600 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0