I am working on setting up Reverse DNS PTR records on my cPanel server but am not getting where I need to. I have the IP addresses delegated to me and a DNS Stuff Reverse DNS lookup tells me there are no PTR records for the IP address. Here is the zone.db file for the IP address:

; Modified by Web Host Manager
; Zone File for 15.175.12.in-addr.arpa
$TTL 86400
@ 14440 IN SOA ns1.digitalpulsehost.net. shane.digitalpulsehost.net. (
2005063012
28800
14440
3600000
86400
)

14440 IN NS ns1.digitalpulsehost.net.
14440 IN NS ns2.digitalpulsehost.net.

139 IN PTR mail.adlmail.com.
138 IN PTR ems.adlmail.com.
153 IN PTR mail.idgwi.com.

When I do a reverse lookup on 12.175.15.139 it gets to my server but my servers says there are no PTR records. Can anyone tell me why? It does get the correct information when I do a "dig -x" on the IP, but this is what I get:

; <<>> DiG 9.2.4 <<>> -x 12.175.15.153
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 8244
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 0

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

;; ANSWER SECTION:
153.15.175.12.in-addr.arpa. 172800 IN CNAME 153.128/25.15.175.12.in-addr.arpa.

;; AUTHORITY SECTION:
15.175.12.in-addr.arpa. 10800 IN SOA ns1.digitalpulsehost.net. shane.digitalpulsehost.net. 2005063011 28800 14440 3600000 86400

;; Query time: 91 msec
;; SERVER: 207.218.192.39#53(207.218.192.39)
;; WHEN: Wed Jul 6 11:35:44 2005
;; MSG SIZE rcvd: 161

Where does it get that CNAME from? It is not in my zone files.

Reverse dns is almost always done by the isp, in this case ev1servers. With the nature of dns it would be much to complex to delegate every single server control of their own rdns/prt records. Login to the members section and from there you can add the reverse dns entries.

You don't understand. The IP addresses ARE delegated to my server from AT&T. They aren't your IP addresses so you CAN'T do the reverse on those. I know you won't delegate the IP's to me and I don't need you to - your RDNS system works fine.

The problem is, these IP addresses ARE delegated to me and the RDNS setup I created isn't working. Has anyone actually done RDNS on a cPanel server or am I an idiot for trying?

If you dig against your nameserver, you get the record that you put in (I would assume):

However, when you just do a dig against the IP, by itself, you get what you're seeing:

This makes me think that somehow AT&T is still getting hit as authoritative for that in-addr.arpa or something, even though you're still showing as SOA. You may need to take it up with them. In fact, if you do a dig +trace, you'll see that what's answering the -x query is AT&T not you:

Hope this helps.

Hmm... I think we may have found the culprit.
Have you tried having 128/25.15.175.12.in-addr.arpa instead of 15.175.12.in-addr.arpa as the zone file? I think that since it was delegated as that from AT&T (the CNAME) you have to have it match exactly. For more information, you may want to read this RFC: http://www.faqs.org/rfcs/rfc2317.html
Optionally, you may be able to get it to work if you change your individual PTR records in your 15.175.12.in-addr.arpa (e.g., change 139 to 139.128/25). This is all a guess right now - RDNS makes my ears bleed.

I have tried to add the 128/25.15.175.12.in-addr.arpa and all the other options but then I get a SERVFAIL with the dig command. I will talk to AT&T to see how they are sending the request to me and maybe that will give me some help as to how to set this up.

Thank you.

Another thing that may help read how things are being translated and passed on would be to use the reverse dns lookup at dnsstuff.com (http://dnsstuff.com/tools/ptr.ch?ip=12.175.15.139 for this one particular IP) - it explains things in (more or less) English.
Please let us know how this turns out - this is going to bug me all night.

P.S. Now I remember why I hate subnet ranges and CNAME records.

digitalpulse -

I found this link last night that I think explains things much more clearly. I'm still digesting it all, but it looks like you need to set your RDNS zone to be a slave and point to AT&T's server as the master to get the delegation to work.

http://www.csh.rit.edu/~jon/text/papers/classless/

Let us know if this works or not, or what does end up working. Thanks!

Unfortunately nothing has helped and no matter what I try it fails. I have turned things back to AT&T so they can do the reverse for us as that takes the burden off of me. Thanks for trying to help, but it's just not worth it for me to continue doing this.