_spf.bell.net has no NS records.
NS records for this zone are defined at bell.net.
NS records for this zone are defined at bell.net.
Question and response
Question
dig _spf.bell.net. NS
Answer
The response has no answer records.
Authority
bell.net. 900 SOA mtl02vnszs08.srvr.bell.ca. trademarks.bell.ca. 6530 10800 3600 2419200 900
Additional
. 0 OPT ; payload 1220, xrcode 0, version 0, flags 0