ip-216.38.1.24.servernap.net has no NS records.
NS records for this zone are defined at servernap.net.
NS records for this zone are defined at servernap.net.
Question and response
Question
dig ip-216.38.1.24.servernap.net. NS
Answer
The response has no answer records.
Authority
servernap.net. 3600 SOA ns1.servernap.com. hostmaster.servernap.com. 2021120800 3600 900 604800 86400
Additional
. 0 OPT ; payload 1680, xrcode 0, version 0, flags 0