digでルートサーバからたどってみたんだが名前解決できん
今繋がってるのはキャッシュか？

$ dig +norec @192.55.83.30 5ch.net

; <<>> DiG 9.10.6 <<>> +norec @192.55.83.30 5ch.net
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 32732
;; flags: qr; QUERY: 1, ANSWER: 0, AUTHORITY: 2, ADDITIONAL: 3

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;5ch.net. IN A

;; AUTHORITY SECTION:
5ch.net. 172800 IN NS dns1.5ch.net.
5ch.net. 172800 IN NS dns2.5ch.net.

;; ADDITIONAL SECTION:
dns1.5ch.net. 172800 IN A 45.88.201.252
dns2.5ch.net. 172800 IN A 45.88.201.252

;; Query time: 255 msec
;; SERVER: 192.55.83.30#53(192.55.83.30)
;; WHEN: Fri Aug 09 09:34:16 JST 2019
;; MSG SIZE rcvd: 106

$ dig +norec @45.88.201.252 5ch.net

; <<>> DiG 9.10.6 <<>> +norec @45.88.201.252 5ch.net
; (1 server found)
;; global options: +cmd
;; connection timed out; no servers could be reached