_sip._udp.kustbandet.com has no NS records.
NS records for this zone are defined at kustbandet.com.
NS records for this zone are defined at kustbandet.com.
Question and response
Question
dig _sip._udp.kustbandet.com. NS
Answer
The response has no answer records.
Authority
kustbandet.com. 38400 SOA ns01.kustbandet.com. hostmaster.kustbandet.com. 1179738999 10800 3600 1209600 38400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0