Apex domains cannot have CNAME records.
Question and response
Question
dig ldp.net.id. NS
Answer
ldp.net.id. 5 NS ns2.ldp.net.id.
ldp.net.id. 5 NS ns1.ldp.net.id.
Authority
The response has no authority records.
Additional
ns1.ldp.net.id. 5 A 124.40.255.10
ns2.ldp.net.id. 5 A 124.40.250.253
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0