d.nic.lk has no CNAME records.
Question and response
Question
dig d.nic.lk. NS
Answer
The response has no answer records.
Authority
lk. 3600 SOA ns.nic.lk. hostmaster.nic.lk. 2020178685 1800 900 2592000 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0