spf2.nuffieldhealth.com has no NS records.
NS records for this zone are defined at nuffieldhealth.com.
NS records for this zone are defined at nuffieldhealth.com.
Question and response
Question
dig spf2.nuffieldhealth.com. NS
Answer
The response has no answer records.
Authority
nuffieldhealth.com. 1800 SOA gail.ns.cloudflare.com. dns.cloudflare.com. 2398538814 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0