6 и 7 только список рутов по логике должны отдавать.
И отдают...
kirya@Kirya ~> dig @2a0c:a9c7:b::1
; <<>> DiG 9.16.1-Ubuntu <<>> @2a0c:a9c7:b::1
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 50758
;; flags: qr aa rd; QUERY: 1, ANSWER: 13, AUTHORITY: 0, ADDITIONAL: 27
;; WARNING: recursion requested but not available
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;. IN NS
;; ANSWER SECTION:
. 518400 IN NS
a.root-servers.net.
. 518400 IN NS
b.root-servers.net.
. 518400 IN NS
c.root-servers.net.
. 518400 IN NS
d.root-servers.net.
И т.д.