mx2.swisslink.ch has no NS records.
NS records for this zone are defined at swisslink.ch.
NS records for this zone are defined at swisslink.ch.
Question and response
Question
dig mx2.swisslink.ch. NS
Answer
The response has no answer records.
Authority
swisslink.ch. 14440 SOA ns1.swisslink.ch. dnsmaster.swisslink.ch. 2026022406 10800 3600 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0