ocean.mirae.net has no CNAME records.
Question and response
Question
dig ocean.mirae.net. NS
Answer
The response has no answer records.
Authority
mirae.net. 429 SOA mirae.net. root.mirae.net. 2011122101 3600 1200 864000 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0