asked on

Reverse DNS to IP

How can I setup a DNS record so that the Reverse DNS for an IP resolves as the IP. I am using bind and I keep getting and error that the PTR records 123.123.123.123 does not point back to the IP.

db.132.123.123.123.in-addr.arpa

132.123.123.123.in-addr.arpa IN SOA mydomain.com. admin.mydomain.com. (
2004042605 ; serial
3600 ; refresh (1 hour)
600 ; retry (10 minutes)
86400 ; expire (1 day)
3600 ; minimum (1 hour)
)
NS ns1.mydomain.com.
NS ns3.mydomain.com.
$TTL 86400 ; 1 day
A 123.123.123.132
PTR 123.123.123.132.

jar3817

I just tried it on my server with this config:

file: /var/named/10.152.74.rev
------- paste ------
$TTL 3600
@ IN SOA dns.example.com. root.example.com. (
2001082001 10800 3600 604800 86400 )
@ IN NS dns.example.com.
1 IN PTR 10.152.74.1.
------ end paste ----

and this is the output of a reverse lookup:

---paste----
[root@example named]# host -v 10.152.74.1
Trying "1.74.152.10.in-addr.arpa"
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 13591
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 0

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

;; ANSWER SECTION:
1.74.152.10.in-addr.arpa. 3600 IN PTR 10.152.74.1.

;; AUTHORITY SECTION:
74.152.10.in-addr.arpa. 3600 IN NS dns.example.com.

Received 97 bytes from 10.152.74.254#53 in 0 ms
---- end paste-----

Is that what you are trying to do?

hexfusion

ASKER

If I do a reverse on 10.152.74.254

http://www.dnsstuff.com/tools/ptr.ch?ip=10.152.74.254

Answer:
No PTR records exist for 10.152.74.254. [Neg TTL=604800 seconds]

I get
Answer:
123.123.123.132 PTR record: 123.123.123.132. [TTL 86400s] [A=None] *ERROR* A record does not point back to original IP.

jar3817

You wont get an answer for my address (its an internal address range (not public)).

Try using a real dns resolver, not that webpage. I think that error message you are getting is generated by the webpage because there is no A record for the "name" 123.123.123.132.

you mentioned this is bind, so open up a console and type "host 123.123.123.132" and see what the output is.

ASKER CERTIFIED SOLUTION

jlevie

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