mx1.nic.fr has no NS records.
NS records for this zone are defined at nic.fr.
NS records for this zone are defined at nic.fr.
Question and response
Question
dig mx1.nic.fr. NS
Answer
The response has no answer records.
Authority
nic.fr. 5400 SOA dnsmaster.nic.fr. hostmaster.nic.fr. 2026022611 7200 1800 2419200 5400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0