How is it possible to contain DNS A records without NS records for a domain?

Question

Today I saw a domain that contains DNS A record but no DNS NS records. How is it possible to create A record without NS Nameservers?

Example domain is: frankstudios.com

dig for A records:

root@ubuntu:~# dig @8.8.8.8 -t A frankstudios.com

; <<>> DiG 9.11.3-1ubuntu1.8-Ubuntu <<>> @8.8.8.8 -t A frankstudios.com
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 28479
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;frankstudios.com.              IN      A

;; ANSWER SECTION:
frankstudios.com.       299     IN      A       207.148.248.143

;; Query time: 98 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Wed Aug 21 11:16:02 UTC 2019
;; MSG SIZE  rcvd: 61

dig for NS records:

root@ubuntu:~# dig @8.8.8.8 -t NS frankstudios.com

; <<>> DiG 9.11.3-1ubuntu1.8-Ubuntu <<>> @8.8.8.8 -t NS frankstudios.com
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 14126
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;frankstudios.com.              IN      NS

;; AUTHORITY SECTION:
frankstudios.com.       299     IN      SOA     ns.buydomains.com. hostmaster.buydomains.com. 2015031114 86400 7200 604800 300

;; Query time: 91 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Wed Aug 21 11:17:00 UTC 2019
;; MSG SIZE  rcvd: 106

This domain is wrongly configured, see https://zonemaster.net/result/cc5171a2b79130f5 and http://dnsviz.net/d/frankstudios.com/dnssec/ The nameservers associated to it do not reply correctly (they do not list themselves as NS records for the domain). Based on that, no observations is valid, what you see are just artifacts. Th DNS configuration of this domain must be fixed first. — Patrick Mevzek, Aug 29 '19 at 04:44

score 4 · Accepted Answer · edited Oct 07 '21 at 06:58

Although a DNS zone should include NS records (because only the in-zone data is authoritative and it is required by the RFCs 1034 and [1035][2]) the nameservers for a domain are discovered by following glue records set by the registrar in the Top Level Domain.

Thus in practice the domain and all the other records will in work without NS records in the zone itself.

You can see that easily in both the whois record and with the +trace option in dig

dig +trace frankstudios.com.@8.8.4.4 :
.           68508   IN  NS  m.root-servers.net.
.           68508   IN  NS  b.root-servers.net.
.           68508   IN  NS  e.root-servers.net.
.           68508   IN  NS  i.root-servers.net.
.           68508   IN  NS  d.root-servers.net.
.           68508   IN  NS  a.root-servers.net.
.           68508   IN  NS  f.root-servers.net.
.           68508   IN  NS  k.root-servers.net.
.           68508   IN  NS  j.root-servers.net.
.           68508   IN  NS  h.root-servers.net.
.           68508   IN  NS  l.root-servers.net.
.           68508   IN  NS  c.root-servers.net.
.           68508   IN  NS  g.root-servers.net.
;; Received 228 bytes from 8.8.4.4#53(8.8.4.4) in 5 ms

com.            172800  IN  NS  a.gtld-servers.net.
com.            172800  IN  NS  e.gtld-servers.net.
com.            172800  IN  NS  f.gtld-servers.net.
com.            172800  IN  NS  k.gtld-servers.net.
com.            172800  IN  NS  c.gtld-servers.net.
com.            172800  IN  NS  i.gtld-servers.net.
com.            172800  IN  NS  j.gtld-servers.net.
com.            172800  IN  NS  h.gtld-servers.net.
com.            172800  IN  NS  l.gtld-servers.net.
com.            172800  IN  NS  b.gtld-servers.net.
com.            172800  IN  NS  d.gtld-servers.net.
com.            172800  IN  NS  g.gtld-servers.net.
com.            172800  IN  NS  m.gtld-servers.net.
;; Received 494 bytes from 199.9.14.201#53(199.9.14.201) in 75 ms

frankstudios.com.   172800  IN  NS  ns.buydomains.com.               <===== GLUE
frankstudios.com.   172800  IN  NS  this-domain-for-sale.com.        <===== GLUE
;; Received 129 bytes from 192.5.6.30#53(192.5.6.30) in 1829 ms

frankstudios.com.   300 IN  A   207.148.248.143
;; Received 50 bytes from 52.20.26.87#53(52.20.26.87) in 22 ms

[2]: https://www.rfc-editor.org/rfc/rfc1035)

" the nameservers for a domain are discovered by following glue records set by the registrar in the Top Level Domain. " glue records exist only for in-bailiwick nameservers and shows as `A` /`AAAA` records. This case is **NOT** glue records at all, just normal delegation (except that the domain is itself badly broken at the DNS level). So this answer is wrong. — Patrick Mevzek, Aug 29 '19 at 04:44

How is it possible to contain DNS A records without NS records for a domain?

1 Answers1