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Windows 2000 RDNS issue:  Please help ASAP!!!

Posted on 2005-04-22
Medium Priority
Last Modified: 2010-04-14
Hello, I have a client that is running their mail server from my network.  The domain that they are using is hosted on another network down in Miami, which is far far away from where I am at.  I am using windows 2000 for my net’s dns.  They are getting mail kicked back due to RDNS errors.  So I made a reverse entry for the mail server’s IP but I do not know what to point it too.  So I made a forward zone and called it mail.example.com; then I created an A record and pointed it to the remote IP.  But I am getting
*ERROR* A record does not point back to original IP.  

What do I need to do to correct this?
Question by:inverted_2000
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LVL 25

Expert Comment

ID: 13845859
you have to make these changes on the PUBLIC dns server, not the private DNS server. undo what you did about creating the forward zone called mail.example.com. that is a subdomain IE any host on it will have a FQDN of hostname.mail.example.com which isn't what you want.

go to www.dnsreport.com and do a test for the domain name in question.  I'm willing to bet it has all kinds of FAIL errors on it.  remember, you have to fix these on their PUBLIC dns server, not on their private dns server.

Author Comment

ID: 13846197
I am their dns server for their internet access

the report showed 1 warning for only having 1 single mx

also the changes where done on a public dns server

there is no private server
LVL 25

Accepted Solution

mikeleebrla earned 1500 total points
ID: 13846272
well that is a pretty exaustive test and the error you got isnt a big one at all, just a warning in fact.  You say that you created the reverse entry but you dont know where to point it to. you point it to whereever the MX record points to. For examply say the mail servers ip is and its MX record points to mail domain.com.  mail.domain.com then in turn points to the IP address of

so then your reverse record would point to mail.domain.com
thats really all there is to creating a  reverse A record.

it could be that their mail server requires a reverse MX record however.
you do this by going to the reverse zone for 1.2.3.x and rightclicking and choose create new other record. from there you can choose a record of the type "mail exchanger".  this will create a reverse MX record rather than just a reverse A record. creating this won't hurt anything

It is possible that the mail server on the sending in just has bad dns records.
It is also possible that the error they are getting doesn't say the real cause. They might be requring SPF records. do you have an SPF record set up?

Author Comment

ID: 13846425
We fixed it!!!

The issue was that we do the DNS for his network and his domain is in Miami...his mail server is here in Boone.  In other words...I do not host his domain and that is why I do not have any MX records for him and if I need them I do not know how to create them.

Anyway, thanks for your help,

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