Apex domains cannot have CNAME records.
Question and response
Question
dig airinternet.ph. NS
Answer
airinternet.ph. 4 NS ns1.metroconnect.com.ph.
airinternet.ph. 4 NS ns9.metroconnect.com.ph.
Authority
The response has no authority records.
Additional
ns1.metroconnect.com.ph. 4 A 202.69.191.11
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0