ns0172.secondary.cloudflare.com has no NS records.
NS records for this zone are defined at cloudflare.com.
NS records for this zone are defined at cloudflare.com.
Question and response
Question
dig ns0172.secondary.cloudflare.com. NS
Answer
The response has no answer records.
Authority
cloudflare.com. 300 SOA ns3.cloudflare.com. dns.cloudflare.com. 2399894953 10000 2400 604800 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0