ip254b3.nic.ao has no CNAME records.
Question and response
Question
dig ip254b3.nic.ao. NS
Answer
The response has no answer records.
Authority
ao. 344 SOA a.ns.ao. hostmaster.dns.ao. 1772909101 86400 7200 2592000 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0