➜ ~ dig in NS

; <<>> DiG 9.16.1-Ubuntu <<>> in NS
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 64139
;; flags: qr rd ad; QUERY: 1, ANSWER: 13, AUTHORITY: 0, ADDITIONAL: 0
;; WARNING: recursion requested but not available

;; QUESTION SECTION:
;. IN NS

;; ANSWER SECTION:
. 0 IN NS m.root-servers.net.
. 0 IN NS b.root-servers.net.
. 0 IN NS c.root-servers.net.
. 0 IN NS d.root-servers.net.
. 0 IN NS e.root-servers.net.
. 0 IN NS f.root-servers.net.
. 0 IN NS g.root-servers.net.
. 0 IN NS h.root-servers.net.
. 0 IN NS a.root-servers.net.
. 0 IN NS i.root-servers.net.
. 0 IN NS j.root-servers.net.
. 0 IN NS k.root-servers.net.
. 0 IN NS l.root-servers.net.

;; Query time: 0 msec
;; SERVER: 172.30.224.1#53(172.30.224.1)
;; WHEN: Fri Jul 15 11:02:18 KST 2022
;; MSG SIZE rcvd: 432

➜ ~ dig in. NS

; <<>> DiG 9.16.1-Ubuntu <<>> in. NS
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 59500
;; flags: qr rd ad; QUERY: 1, ANSWER: 6, AUTHORITY: 0, ADDITIONAL: 0
;; WARNING: recursion requested but not available

;; QUESTION SECTION:
;in. IN NS

;; ANSWER SECTION:
in. 0 IN NS ns1.registry.in.
in. 0 IN NS ns3.registry.in.
in. 0 IN NS ns2.registry.in.
in. 0 IN NS ns4.registry.in.
in. 0 IN NS ns5.registry.in.
in. 0 IN NS ns6.registry.in.

;; Query time: 120 msec
;; SERVER: 172.30.224.1#53(172.30.224.1)
;; WHEN: Fri Jul 15 11:02:25 KST 2022
;; MSG SIZE rcvd: 196