I had configured a DNS server.But when nslookup with the IP address of the DNS server. It shows something like that"x.x.x.x.in-addr.arpa name=dns.domain.com". But when i nslookup with the dns.domain.com output is ok.
The output of nslookup is to be expected.
When you look up an IP address for which a PTR record is set up, the result is that same IP address, with the octets printed in reverse order, ending with
Finally, you get the corresponding fully qualified domain name set in the PTR record.
If a PTR record is not set, you will get NXDOMAIN as a lookup result for that IP address.
Example of a result of a reverse lookup with a PTR record
I do a lookup of twitter.com
I now do a reverse lookup of the first result of my previous lookup.
Ok, so it turns out that the folks at twitter set up a PTR record for that IP address (note that the octets of the IP in the output are reversed, beginning with 10 and ending with 199) that points to r-199-59-148-10.twttr.com.
Example of a result of a reverse lookup without a PTR record
The result is only one IP address, let's do a reverse lookup on that.
Again, the octets in the output have been reversed and appended with