2

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
Temüjin
  • 133

1 Answers1

4

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)

HBruijn
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