Sources:

• IBM NS1 - Decoding DIG Output
• serverfault - How to determine which DNS server has the authority to set rDNS (PTR records)?
• linux.die.net - dig(1) - Linux man page

dig -t ANY @a.ns14.net nanoscopic.de

• dig: calling the command dig
• -t ANY: specifying the query type
• @a.ns14.net: specifying the DNS server to query
• nanoscopic.de: the name to query for

dig -t SOA nanoscopic.de

; <<>> DiG 9.18.26 <<>> -t SOA nanoscopic.de
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 22729
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1424
;; QUESTION SECTION:
;nanoscopic.de.                 IN      SOA

;; ANSWER SECTION:
nanoscopic.de.          3600    IN      SOA     a.ns14.net. domains.wiretrip.de. 2024031401 43200 7200 1209600 3600

;; Query time: 26 msec
;; SERVER: 192.168.1.1#53(192.168.1.1) (UDP)
;; WHEN: Mon May 06 17:50:07 CEST 2024
;; MSG SIZE  rcvd: 105

The authoritative DNS server for nanoscopic.de is a.ns14.net.

To get current DNS data, use @<HOSTNAME_OF_AUTHORITATIVE_DNS_SERVER>.

dig @a.ns14.net -t A nanoscopic.de

; <<>> DiG 9.18.26 <<>> @a.ns14.net -t A nanoscopic.de
; (2 servers found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 32234
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
;; WARNING: recursion requested but not available

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

;; ANSWER SECTION:
nanoscopic.de.          3600    IN      A       159.69.16.204

;; Query time: 16 msec
;; SERVER: 62.116.159.231#53(a.ns14.net) (UDP)
;; WHEN: Mon May 06 17:56:47 CEST 2024
;; MSG SIZE  rcvd: 58

dig @a.ns14.net -t AAAA nanoscopic.de

; <<>> DiG 9.18.26 <<>> @a.ns14.net -t AAAA nanoscopic.de
; (2 servers found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 21488
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;nanoscopic.de.                 IN      AAAA

;; ANSWER SECTION:
nanoscopic.de.          3600    IN      AAAA    2a01:4f8:c0c:fa5c::1

;; Query time: 16 msec
;; SERVER: 62.116.159.231#53(a.ns14.net) (UDP)
;; WHEN: Mon May 06 17:58:31 CEST 2024
;; MSG SIZE  rcvd: 70

Works for IPv4 and IPV6 addresses

IPADDR="80.147.157.18"; IPADDR="$( dig -x $IPADDR | egrep '^;.*PTR$' | cut -c 2- | awk '{print $1}' )"; dig in ns $IPADDR;

; <<>> DiG 9.18.26 <<>> in ns 18.157.147.80.in-addr.arpa.
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 29955
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1424
;; QUESTION SECTION:
;18.157.147.80.in-addr.arpa.    IN      NS

;; AUTHORITY SECTION:
157.147.80.in-addr.arpa. 3600   IN      SOA     pns.dtag.de. dns.telekom.de. 2024050700 86400 7200 3600000 3600

;; Query time: 39 msec
;; SERVER: 192.168.1.1#53(192.168.1.1) (UDP)
;; WHEN: Tue May 07 14:55:38 CEST 2024
;; MSG SIZE  rcvd: 114

The DNS server, serving the PTR record for 80.147.157.18 (nanoscopic.de), is pns.dtag.de.

For IPv6 addresses, e.g. 2003:a:b1c:f420:be24:11ff:feb3:a94f, replace the last four hexadecimal digits with a zero: 2003:a:b1c:f420:be24:11ff:feb3:0.

To get current RDNS data, use @<HOSTNAME_OF_RDNS_SERVER>.

dig @pns.dtag.de -x 2003:a:b1c:f420:be24:11ff:feb3:a94f

; <<>> DiG 9.18.26 <<>> @pns.dtag.de -x 2003:a:b1c:f420:be24:11ff:feb3:a94f
; (2 servers found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 57046
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
; COOKIE: 0df13100e908f31301000000663a234b9c80aa6cf1625885 (good)
;; QUESTION SECTION:
;f.4.9.a.3.b.e.f.f.f.1.1.4.2.e.b.0.2.4.f.c.1.b.0.a.0.0.0.3.0.0.2.ip6.arpa. IN PTR

;; ANSWER SECTION:
f.4.9.a.3.b.e.f.f.f.1.1.4.2.e.b.0.2.4.f.c.1.b.0.a.0.0.0.3.0.0.2.ip6.arpa. 86400 IN PTR mail.ignion.de.

;; Query time: 9 msec
;; SERVER: 2003:40:8000::100#53(pns.dtag.de) (UDP)
;; WHEN: Tue May 07 14:49:15 CEST 2024
;; MSG SIZE  rcvd: 157

~~DISCUSSION~~