isp.swan.sk has no NS records.
NS records for this zone are defined at swan.sk.
NS records for this zone are defined at swan.sk.
Question and response
Question
dig isp.swan.sk. NS
Answer
The response has no answer records.
Authority
swan.sk. 3600 SOA auth1.ns.swan.sk. hostmaster.swan.sk. 2026030601 86400 7200 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0