spf.ivnosys.net has no NS records.
NS records for this zone are defined at ivnosys.net.
NS records for this zone are defined at ivnosys.net.
Question and response
Question
dig spf.ivnosys.net. NS
Answer
The response has no answer records.
Authority
ivnosys.net. 21600 SOA ns1.ivnosys.net. sistemas.ivnosys.com. 1770886836 7200 3600 1209600 21600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0