I have followed this guide, but still no way. "it" is resolved, but "polito.it" does not resolve, for example.

I want to go directly to the source, i mean, if i want to resolve, for example www.polito.it, i want to ask "it", then "polito.it"... This is what Unbound should be doing.

Instead, i can resolve it:

server /etc # dig it @127.0.0.1

; <<>> DiG 9.16.48 <<>> it @127.0.0.1
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 59860
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;it.                            IN      A

;; AUTHORITY SECTION:
it.                     3194    IN      SOA     dns.nic.it. hostmaster.nic.it. 2024062114 10800 900 604800 3600

;; Query time: 0 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Fri Jun 21 14:50:06 CEST 2024
;; MSG SIZE  rcvd: 86

Instead i cannot resolve polito.it:

server /etc # dig polito.it @127.0.0.1

; <<>> DiG 9.16.48 <<>> polito.it @127.0.0.1
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 60832
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;polito.it.                     IN      A

;; Query time: 1180 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Fri Jun 21 14:50:40 CEST 2024
;; MSG SIZE  rcvd: 38

Nothing appears in the logs. It resolve fine using 8.8.8.8 as upstream DNS.