A Valid domain name without TLD on internet

Does any body know how is this a valid Domain name?

That's not a valid domain name:

$ dig good

; <<>> DiG 9.8.3-P1 <<>> good ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 65133 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION: ;good. IN A

;; Query time: 3 msec ;; SERVER: 192.168.11.1#53(192.168.11.1) ;; WHEN: Mon Feb 19 12:13:28 2018 ;; MSG SIZE rcvd: 22

I works because most browsers try to add ".com" to an invalid domain name. And good.com is valid

$ dig good.com

; <<>> DiG 9.8.3-P1 <<>> good.com ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 57755 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION: ;good.com. IN A

;; ANSWER SECTION: good.com. 19030 IN A 216.136.156.80

;; Query time: 4 msec ;; SERVER: 192.168.11.1#53(192.168.11.1) ;; WHEN: Mon Feb 19 12:14:05 2018 ;; MSG SIZE rcvd: 42

And http://good.com redirects after some jumps to http://us.blackberry.com/

pratikborsadiya 8y ago ↗

Try opening the URL in your browser it's working. Or use $host good to find the Ip address of the server

detaro 8y ago ↗

> Try opening the URL in your browser it's working.

As the parent said, browsers try to fix bad domains by themselves.

> $host good to find the Ip address of the server

NXDOMAIN. if you get something else, your DNS provider is injecting something.

fabrixxm 8y ago ↗

> use $host good to find the Ip address of the server

    $ host good
    Host good not found: 2(SERVFAIL)
    
    $ host good.com
    good.com has address 216.136.156.80
    [...]

TomMarius 8y ago ↗

This is not "without TLD", this is literally just the TLD.

detaro 8y ago ↗

As far as I can tell there is no .good gTLD.

TomMarius 8y ago ↗

I'm not talking about gTLDs. TLD is a term with multiple meanings.

detaro 8y ago ↗

Ah, misunderstood your point. If there were a .good TLD, then that could be an explanation for why it works.

[deleted] 8y ago ↗

(comment deleted)