# Reverse DNS resolving problem



## bsaidus (Mar 28, 2012)

Hello,

As in my previous request at DNS Server Behind Nat Router & Nat Firewall, there's still a little problem. This problem is: when I do *nslookup* for my domain name, it works well but still not working for a reverse nslookup.

```
nslookup mydomain.com    => 41.111.100.152  : Works well but
 nslookup 41.111.100.152  => ???             : Not working.
```
PS: I have one public IP address and I use a NAT from router to my internal server as indicated previously. *H*ere is the the source of the forword DNS source: 

```
IN NS   ns1.mycompany.com.
ns1                  IN A    41.111.100.152
mycompany.com.       IN A    41.111.100.152
mycompany.com.       IN MX   10 rmailxp.mycompany.com.
mailxp               IN A    41.111.100.152
www                  IN CNAME   mycompany.com.
webmail              IN A    41.111.100.152
```
I have tried all possibilities with in the reverse zone but sill not working. I have tried to point my public IP and my internal server IP but nothing is working.

So please if someone can help me to solve this because I read somewhere that it is necessary for mailserver to resolve reverse DNS.

thanks in advence.


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## DutchDaemon (Mar 28, 2012)

Is reverse DNS for this IP address (or range) actually delegated to you by the owner of that IP address (which I presume is your ISP)? If you perform a [cmd=]dig -x your_ip[/cmd] you will either find the authoritative nameservers in the AUTHORITY SECTION, or if there are no DNS servers for that zone, the SOA record indicating who "owns" the reverse DNS zone.

The IP address you posted and the IP address you posted from are both not delegated and don't even have an in-addr.arpa zone.

Or do you want to "fake" a reverse DNS zone for your own LAN? You could probably use the hosts file on the mailserver.


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## bsaidus (Mar 28, 2012)

hello.
here is the result of the dig -x 


```
; <<>> DiG 9.7.0-P1 <<>> -x 41.111.100.152
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: REFUSED, id: 30785
;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0
;; WARNING: recursion requested but not available

;; QUESTION SECTION:
;152.100.111.41.in-addr.arpa.   IN      PTR

;; Query time: 205 msec
;; SERVER: 41.111.100.152#53(41.111.100.152)
;; WHEN: Wed Mar 28 16:46:58 2012
;; MSG SIZE  rcvd: 45
```


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## DutchDaemon (Mar 28, 2012)

If you want a local zone in BIND, I'll give you an example:

/etc/namedb/master/db.172.16.110:


```
$TTL    3600

110.16.172.in-addr.arpa.        IN      SOA     your.name.server. root.your.name.server.  (
                                2008101302      ; Serial
                                3600    ; Refresh
                                900     ; Retry
                                3600000 ; Expire
                                3600 )  ; Minimum
        IN      NS      some.name.server.

1       IN      PTR     host1.your.doman.
2       IN      PTR     host2.your.domain.
```

In named.conf:


```
zone "110.16.172.in-addr.arpa" {
        type master;
        file "master/db.172.16.110";
};
```

Shouldn't be more difficult than that.


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## pinguim007 (Dec 7, 2012)

*Public IP or Private IP*

Hello,

I have a server with a cuple domains,
How can I create a reverse zone for all.

Should I create with my private ip network or with my public Ip network?

Thanks


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