xlink1.xlink.net has no NS records.
NS records for this zone are defined at xlink.net.
NS records for this zone are defined at xlink.net.
Question and response
Question
dig xlink1.xlink.net. NS
Answer
The response has no answer records.
Authority
xlink.net. 86400 SOA karlsruhe.nic.xlink.net. hostmaster.xlink.net. 2022091601 86400 7200 604800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0