ustsu1.ust.hk has no CNAME records.
Question and response
Question
dig ustsu1.ust.hk. NS
Answer
The response has no answer records.
Authority
ust.hk. 480 SOA a1-251.akam.net. postmaster.ust.hk. 2020040214 3600 1200 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0