invalid has no NS records.
NS records for this zone are defined at invalid..
NS records for this zone are defined at invalid..
Question and response
Question
dig invalid. NS
Answer
The response has no answer records.
Authority
. 86400 SOA a.root-servers.net. nstld.verisign-grs.com. 2026022200 1800 900 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0