231.132.5.213.ptr.as50391.net has no NS records.
NS records for this zone are defined at as50391.net.
NS records for this zone are defined at as50391.net.
Question and response
Question
dig 231.132.5.213.ptr.as50391.net. NS
Answer
The response has no answer records.
Authority
as50391.net. 1800 SOA elle.ns.cloudflare.com. dns.cloudflare.com. 2398840863 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0