yahoo.byggbutiken.com has no NS records.
NS records for this zone are defined at byggbutiken.com.
NS records for this zone are defined at byggbutiken.com.
Question and response
Question
dig yahoo.byggbutiken.com. NS
Answer
The response has no answer records.
Authority
byggbutiken.com. 3601 SOA dns1.registrar-servers.com. hostmaster.registrar-servers.com. 1763566932 43200 3600 604800 3601
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0