237.192-255.76.50.195.in-addr.arpa has no NS records.
NS records for this zone are defined at 192-255.76.50.195.in-addr.arpa.
NS records for this zone are defined at 192-255.76.50.195.in-addr.arpa.
Question and response
Question
dig 237.192-255.76.50.195.in-addr.arpa. NS
Answer
The response has no answer records.
Authority
192-255.76.50.195.in-addr.arpa. 86400 SOA pdns1.ultradns.net. awong.callidussoftware.com. 2017090805 86400 86400 86400 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0