d.spf.avature.net has no NS records.
NS records for this zone are defined at spf.avature.net.
NS records for this zone are defined at spf.avature.net.
Question and response
Question
dig d.spf.avature.net. NS
Answer
The response has no answer records.
Authority
spf.avature.net. 900 SOA ns-1699.awsdns-20.co.uk. awsdns-hostmaster.amazon.com. 1 7200 900 1209600 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0