googlestring.bluecoatcloud.com has no NS records.
NS records for this zone are defined at bluecoatcloud.com.
NS records for this zone are defined at bluecoatcloud.com.
Question and response
Question
dig googlestring.bluecoatcloud.com. NS
Answer
The response has no answer records.
Authority
bluecoatcloud.com. 120 SOA ns1-253.akam.net. hostmaster.akamai.com. 1553197571 43200 7200 604800 120
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0