spf.gc.onl has no NS records.
NS records for this zone are defined at gc.onl.
NS records for this zone are defined at gc.onl.
Question and response
Question
dig spf.gc.onl. NS
Answer
The response has no answer records.
Authority
gc.onl. 300 SOA ns1.gcorelabs.net. support.gcorelabs.com. 1774370929 5400 5400 1209600 300
Additional
. 0 OPT ; payload 1280, xrcode 0, version 0, flags 0