[wplug] Reverse DNS - PTR Record

[Chris Ott]

Ken Rambler wrote:
> I'm not sure exactly how to ask this question, so I apologize in advance.
> 
> My question is related to the PTR record and reverse DNS of a public IP 
> address.
> 
> We operate a mail server and our own DNS server. The public business IP 
> (static) address is provided by our ISP, which is Comcast. The reverse 
> DNS points back to their name, i.e.:
> 
> Asking NS1.COMCASTBUSINESS.NET. for xx.xxx.xx.xx.in-addr.arpa PTR 
> record: Reports xx-xx-xxx-xx-pa.hfc.comcastbusiness.net
> 
> Now the question: Shouldn't the reverse point back to our server name? 

Yes.

> Is this something we could override by adding an entry into our zone file?

I don't know if this is the rule or the exception, but we had to talk to 
our ISP to make that work. They are apparently responsible for reverse 
lookup.

> The reason I question this is that our mail looks to be forged when the 
> server domain name does not match the reverse dns of our IP address.

Yeah, you definitely want to take care of that, especially with the spam 
problem the way it is.

Chris