91.66-126.196.129.23.in-addr.arpa has no NS records.
NS records for this zone are defined at 196.129.23.in-addr.arpa.
NS records for this zone are defined at 196.129.23.in-addr.arpa.
Question and response
Question
dig 91.66-126.196.129.23.in-addr.arpa. NS
Answer
The response has no answer records.
Authority
66-126.196.129.23.in-addr.arpa. 3600 SOA a.misconfigured.dns.server.invalid. hostmaster.66-126.196.129.23.in-addr.arpa. 0 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0