dig redhat.com
;; QUESTION SECTION:
;redhat.com. IN A
;; ANSWER SECTION:
redhat.com. 3600 IN A 209.132.183.105
We get the ip address 209.132.183.105
----the A record of domain redhat.com
.
Now i want to get the domain name from the ip--209.132.183.105
.
Maybe you introduce two ways to get it.
nslookup 209.132.183.105
Server: 192.168.1.1
Address: 192.168.1.1#53
Non-authoritative answer:
105.183.132.209.in-addr.arpa name = redirect.redhat.com.
Authoritative answers can be found from:
dig -x 209.132.183.105
; <<>> DiG 9.9.5-9+deb8u7-Debian <<>> -x 209.132.183.105
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 62599
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1280
;; QUESTION SECTION:
;105.183.132.209.in-addr.arpa. IN PTR
;; ANSWER SECTION:
105.183.132.209.in-addr.arpa. 519 IN PTR redirect.redhat.com.
;; Query time: 1 msec
;; SERVER: 192.168.1.1#53(192.168.1.1)
;; WHEN: Sat Nov 19 15:11:33 CST 2016
;; MSG SIZE rcvd: 90
It is unlucky taht the result is not redhat.com
and redirect.redhat.com
is a PTR record with 209.132.183.105
.
Could i draw a conclusion that no way to get a domain name from the IP address in condition of that the ip is A record of domain name?
You are correct in that there is no way to get the info reliably.
Anyone who owns a domain name can point any A
, AAAA
or CNAME
to whatever IP address they like irrespective if they control that IP address.
It gets even more complex in that if you have the reverse delegation set up for your IP address(es) you can set whatever PTR
record you like - even stuff that's invalid or none existent.
If you owned the domain rubber-chickens.com
there is nothing stopping you creating the following;
google.rubber-chickens.com A 216.58.210.36
- Which points to google or
200.200.120.11 PTR msn.microsoft.com.
- Which when you did a traceroute
or dig
would appear to show the hostname msn.microsoft.com
IP's and domains are just made up in this example.