mdns2.appriver.com has no NS records.
NS records for this zone are defined at appriver.com.
NS records for this zone are defined at appriver.com.
Question and response
Question
dig mdns2.appriver.com. NS
Answer
The response has no answer records.
Authority
appriver.com. 1800 SOA hugh.ns.cloudflare.com. dns.cloudflare.com. 2397032929 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0