mx4.netia.pl has no NS records.
NS records for this zone are defined at netia.pl.
NS records for this zone are defined at netia.pl.
Question and response
Question
dig mx4.netia.pl. NS
Answer
The response has no answer records.
Authority
netia.pl. 600 SOA ns1.internetia.pl. root.ns1.internetia.pl. 2026022100 86400 7200 2592000 345600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0