proxy3.seed.net.tw has no CNAME records.
Question and response
Question
dig proxy3.seed.net.tw. NS
Answer
The response has no answer records.
Authority
seed.net.tw. 508 SOA dns1.seed.net.tw. dnssrv.du.net.tw. 2016011914 21600 7200 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0