_netblocks1.cgi.com has no CNAME records.
Question and response
Question
dig _netblocks1.cgi.com. NS
Answer
The response has no answer records.
Authority
cgi.com. 594 SOA ns.cgi.com. dnsops\.gto.cgi.com. 790816514 1200 180 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0