_spf.vianet.ca has no NS records.
NS records for this zone are defined at vianet.ca.
NS records for this zone are defined at vianet.ca.
Question and response
Question
dig _spf.vianet.ca. NS
Answer
The response has no answer records.
Authority
vianet.ca. 900 SOA gwn.vianet.ca. hostmaster.vianet.ca. 1772757889 600 900 604800 900
Additional
The response has no additional records.