_spf6.gooddata.com has no NS records.
NS records for this zone are defined at gooddata.com.
NS records for this zone are defined at gooddata.com.
Question and response
Question
dig _spf6.gooddata.com. NS
Answer
The response has no answer records.
Authority
gooddata.com. 900 SOA dns1.p01.nsone.net. hostmaster.nsone.net. 1654606864 3600 600 604800 900
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0