spf.fdn.fr has no NS records.
NS records for this zone are defined at fdn.fr.
NS records for this zone are defined at fdn.fr.
Question and response
Question
dig spf.fdn.fr. NS
Answer
The response has no answer records.
Authority
fdn.fr. 86400 SOA nsa.fdn.org. hostmaster.fdn.fr. 2026031231 28800 7200 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0