Is a CNAME record public

3
votes

For example, I have a GitHub Pages site with a custom domain.
Here are the dns records for the domain: enter image description here
Is this CNAME record public?
Or is there a way for someone to determine the GitHub Pages url, ajzbc.github.io, from my custom domain ajzbc.com

To clarify, is there for example a command I could run that would output the CNAME?

Thanks

2
dnsgithub-pagescname
If by public you mean accessible by the public, yes it is. – Tachyon
@Tachyon How would someone see this record? Something like dig ajzbc.com? – andrewjazbec
Depending on what OS you're on you can do it in different ways. For instance on Windows you can open cmd type in, nslookup then type=CNAME then ajzbc.com and hit enter and it should return all the CNAME records for that domain. – Tachyon
@Tachyon I have tried that before. Got this error connection timed out; no servers could be reached – andrewjazbec
That would then be an underlying issue with either your connection to your DNS provider or the provider itself. – Tachyon

2 Answers

4
votes

For main domain : dig ajzbc.com

For www subdomain : dig www.ajzbc.com

1
votes
dbajic@ ~ $ dig www.ajzbc.com

; <<>> DiG 9.10.6 <<>> www.ajzbc.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 62752
;; flags: qr rd ra; QUERY: 1, ANSWER: 5, AUTHORITY: 0, ADDITIONAL: 1

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

;; ANSWER SECTION:
www.ajzbc.com.      1798    IN  CNAME   ajzbc.github.io.
ajzbc.github.io.    3599    IN  A   185.199.109.153
ajzbc.github.io.    3599    IN  A   185.199.108.153
ajzbc.github.io.    3599    IN  A   185.199.110.153
ajzbc.github.io.    3599    IN  A   185.199.111.153

;; Query time: 51 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Tue Feb 26 10:27:47 CET 2019
;; MSG SIZE  rcvd: 135

dbajic@ ~ $