ipv6.cloud.do has no NS records.
NS records for this zone are defined at cloud.do.
NS records for this zone are defined at cloud.do.
Question and response
Question
dig ipv6.cloud.do. NS
Answer
The response has no answer records.
Authority
cloud.do. 1800 SOA iris.ns.cloudflare.com. dns.cloudflare.com. 2396769180 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0