pbx-sip.knipp.de has no NS records.
NS records for this zone are defined at knipp.de.
NS records for this zone are defined at knipp.de.
Question and response
Question
dig pbx-sip.knipp.de. NS
Answer
The response has no answer records.
Authority
knipp.de. 900 SOA ns7.knipp.de. dnsmaster.knipp.de. 2026031046 10800 3600 604800 900
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0