Aug 12, 2004
I am attempting to setup rDNS by following these instructions. I believe that I should have this for my own server which will facilitate rDNS for all my customer's domains on my server.

My real need is to setup a rDNS for an offsite mail server. My server hosts the web site and my nameserver has the customer's offsite mail server MX record.

For discussion's purposes, my server ip is My customer's offsite mail server is

I added a new DNS zone following the instructions.

You now have your PTR zone. It should have your ns1.* and ns2.* name servers listed. As well as a mx entry.
However my new zone does not show my nameservers in the records. Instead I get records from ARIN.NET.

1. Do I need to add NS records to my new zone for my name servers?

2. Do I need to add another zone for my offsite mail server (ip:

I have not added any PTR records yet.

3. Should I add PTR records for the name servers?


Aug 12, 2004
I have found the origin of my problem.

You will most likely want to choose system or root to manage this domain as you probably don't want your customers messing with rDNS.
The above advice sounds logical and is the option that I want.

So I interpret this advice by going to the Account Selection box and select "(system)" under Domains. The page then automatically selects "root" under Users. Then the right side of this Account Selection box is updated with the results from your account selection. It starts out saying "Account Information will be displayed here after you select an account." After selecting the "(system)" account it says "Updating Account Information...". However, that message should have been replaced with the corresponding account information (e.g. IP, Owner, Email, etc.).

If I select a regular web site account, the account information is displayed. But selecting the "(system)" Domain yields not information to update and display.

I believe the problem is that some of this information is used with a DNS Zone Template to produce the final DNS Zone Information. I have no information to substitute so I do not get the results specified in this posting.

Either: 1) I do not have a valid WHM setup. Yet every other function works as documented.
2) This post is outdated.
3) I have discovered a bug

I am still stuck trying to figure out how to properly add a DNS zone. Further comments would be greatly appreciated.

p.s. I am running:
WHM 11.15.0 cPanel 11.17.0-R19434
FEDORA 1 i686 on virtuozzo - WHM X v3.1.0


Nov 19, 2007
reverse dns

This is completely untrue as well. Just cause you don't know how to do something doesn't mean it can't be done. I have a server farm with each server running cPanel. Each server controls its very own name space. Every last rDNS entry is made directly through WHM.
I am going to be setting up cpanel and
need to control dns for my class c. Please advise how to do this through WHM.


Aug 12, 2004
I finally got my rDNS set but I could not use WHM because of the nature of my addresses. However I learned a few things.

First the information given by wired420 is correct as far as DNS. There is a lot of good information that describe reverse zones like wired420's example. I liked the example at the Redhat doc about bind:

I never did figure out if WHM has a problem with the Add a DNS Zone in WHM. But this page uses the script adddns from the scripts directory. However, this script has been replaced by add_dns in February of 2008.

I had better results running the script like this:
./add_dns --ip=

That gave me a zone with all of the records of a standard account. I edited that zone in WHM to remove nonsensical records like MX and CNAME so it is similar to the Redhat doc example. And I added a PTR record.

But I am not the owner of the IP address in the first place. Only the domain names. So my provider's support had to setup the PTR record. My work was for naught.

Be sure you understand your name server's relationship with other name servers.

Adding a zone in WHM using zone templates would be highly advantageous. I never figured out how you use the templates that are there.

Some documentaion would be really really swell.


Aug 10, 2006
How does your example apply if I have ip's on different subnets. For example my main shared ip is on, and ns1, and ns2 are on, and I can't add PTR's for the name servers in the same zone if they're on a different subnet.


Well-Known Member
Aug 19, 2007
Does this procedure work if multiple domains are sharing the same IP, or do I have to have an IP dedicated for each domain name that I want a PTR for?


Well-Known Member
Mar 2, 2004
What does this mean?

ATT says I must enter the rdns on my server like this:

and if I don't, it won't work.

I don't see how this fits into the procedure above. Can someone provide some advice for me on this? Thanks


Well-Known Member
Jun 9, 2008
My data center has given me delegation over the IPs I need to set up rDNS for. I've set up the zone as listed here. When I save the zone, I get the confirmation message but it ends with:

Reconfiguring Local Mail: [checkmx] Unable to resolve to an ip address. Forcing changes because always accept has been forced.

Zone Modified!
Should I worry about that? Everything seems to work fine including e-mail.

Thanks in advance....


Well-Known Member
Jun 9, 2008
I have corresponding A entries for all of the IPs I had my data center delegate. I didn't create an A entry for:

I simply followed the steps given in this thread to create the DNS zone.

Do I need to create an A entry or do something else for that entry too (the entry)?



Well-Known Member
Jun 9, 2008
I followed this tutorial to the letter, and that is the name of the zone I created. I then added the specific IPs that I wanted to reverse (after the data center delegated them).

WHM created some things in this file automatically, and on further review I notice there actually is an A entry for "" that does point to the right IP.



Well-Known Member
Feb 3, 2004
Sydney / Australia
every since the last cPanel upgrade my main DNS server i used to manage 3 C-classes PTR is not working anymore.

Here is the error

Reconfiguring Local Mail: [checkmx] Unable to resolve to an ip address. Forcing changes because always accept has been forced.

Has anybody else experienced this issue ?


Apr 1, 2008
Hi all friends,

need your help on PTR records, I did as this tutorial but when I send an email, I received reply from the server

SMTP error from remote mail server after initial connection:
host [***.***.***.***]: 521 Service not available - no PTR record for = my Server's IP


Well-Known Member
Apr 30, 2003
Washington Court House, Ohio, United States
cPanel Access Level
DataCenter Provider
PTR works when asking server via nslookup but not out on web?

Strange -

PTR works when we ask the local nameserver via nslookup (even from external network ) - however
when doing it via dnsstuff - it errors out.

Any ideas?

port 53 is live

nevermind - timewarner named it something funny - so had to do a few tricks to get it to work.
go figure
Last edited:


Active Member
Staff member
Oct 14, 2008
Classless subnet PTR

A client brought to my attention that if you are delegated smaller than a class C that a line for subnet designation needs to be added. You can see this as the last line. This is in example of a /25 starting at 0

; cPanel first:11.24.4-CURRENT_36167 latest:11.24.4-NIGHTLY_35533 Cpanel::ZoneFile::VERSION:1.2 mtime:1244221256
; Zone file for
$TTL 14400 86400 IN SOA (
2009052011 ;Serial Number
86400 ;refresh
7200 ;retry
3600000 ;expire
86400 ;minimum
localhost 14400 IN A
0 14400 IN PTR
1 14400 IN PTR
2 14400 IN PTR
127 14400 IN PTR
127.0/25 14400 IN PTR

for a /26 starting at 64 the last PTR would be 127.64/26


Aug 9, 2009
Really working zone file

Actually, I tried all examples of zone files on all forums google served. And they all didn't work. Finally, I figured out CentOS is RHEL4 and therefore there has to be proper documentation for this. And the example from 12.3.4. Reverse Name Resolution Zone Files solved all my problems. If you dig -x shows an error, try to get this example and modify it to your needs.


Jun 24, 2005
Unless you are the IP registrant, you can't issue a PTR record yourself ...

(IE: Your DNS is the one that controls the zone for the numeric IP)

Lookup your IP address using the WHOIS interface at
and that will tell you who is the registrant for your IP number and that is
who will need to add the PTR record to their DNS servers.

This is almost always whoever provided you with your server or the data center
if your server is colocated in a data center and you will need to contact them
and ask them to put the PTR record for your IP in their own DNS servers.

Simply adding a PTR record to the zone files on your server won't do any
good whatsoever if you aren't the IP registrant. You can resolve hostnames to IP addresses locally but not the other way around.


Mar 5, 2010
Further Reverse delegation by ISP to customer B

An ISP submit eg. in IP authority eg. APNIC/RIPE/ARIN to point reverse delegation of to ISP DNS eg. and

in and

ISP create a reverse zone for

Now the question : ISP has 2 customer.

Customer A - ISP assign and host with ISP DNS. Mail ip is
Customer B - ISP assign and host on own DNS. Mail ip is

For Customer A, ISP creates zone for and also ptr record for

10 14400 IN PTR

For Customer B, ISP cannot create zone in its DNS since the customer has its own DNS. In this case, how could ISP further sub-delegate the to Customer B's DNS so that customer B could create a reverse zone for as well as PTR record in its DNS?

200 14400 IN PTR