cdn.pmisites.com has no NS records.
NS records for this zone are defined at pmisites.com.
NS records for this zone are defined at pmisites.com.
Question and response
Question
dig cdn.pmisites.com. NS
Answer
The response has no answer records.
Authority
pmisites.com. 3601 SOA dns1.registrar-servers.com. hostmaster.registrar-servers.com. 1772114469 43200 3600 604800 3601
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0