Automated creation of PTR records for all new domains.

[jdlitson]

I have a client with many domains with the .nl and .eu extension.
It seems that those extensions have issues resolving unless they contain a PTR record. <IP> PTR <domain.ext>.

DA allows you to create custom templates for (A) records ,(mx), etc., but not (PTR) records. I have made a custom dns_ptr.conf file but DA doesn't read it. I didn't think it would since it is not one of the supported custom files according to the README in the templates directory.

Any suggestions would be greatly appreciated.

Jason

 

[Daredevil]

Unfortunatly DA does not support a custom PTR template, nor is one really needed. As a reference my .nl and .eu are working without problems with just one, serverwide PTR record.

Some "official" information given by John;

Hello,

We didn't add the PTR version of the template.. as PTR records aren't generally added to the zones.. perhaps if you could explain why it would be needed, I could look into adding that one as well. (A ptr record generally happens once per IP, not per domain)

John

&

Hello,

Domains don't use PTR records, reverse IP lookups use PTR records to resolve to one domain per IP... (multiple domains can resolve to the same IP, but reverse IP lookups can only resolve to one domain (more or less))

http://www.directadmin.com/forum/showthread.php?s=&threadid=2175&highlight=reverse+ip

You really only need to do the reverse lookup once for the server IP.

John

Above posts can be found in this thread.

 

[jdlitson]

Hi Daredevil,
Thanks so much for your thorough and easy to understand response.
My client also has many dedicated IPs since he uses many SSL certs, so this would explain then; why it would seem that the .nl and .eu domains would require a PTR record when it is actually only each dedicated IP.

Thanks again for your time and help,

Jason

 

[nobaloney]

Starting at the beginning:

The root of all pointer (reverse DNS) records is the in-addr.arpa domain; more information and a short history can be found here.

Reverse DNS is in no way connected to your standard DNS. And you don't get it automatically when you register your nameserver at your registrar.

In order to serve reverse DNS, you have to have authority to do so. That authority is passed down through the in-addr.arpa domain. Normally the way you'd get such authority is if your connectivity provider gives it to you. So the first step is to ask your upstream to give you authority for your IP#s (and normally they won't unless you have a C-Class (256 IP#s) or above, though there are many exceptions (my DSL provider gives it to me for my office network of only 8 IP#s).

If they won't give it to you, then they'll have to manage the reverse DNS (pointer) records for you.

While it's technically possible to have many records for your pointer records, all pointing the same IP#s to different domain names, to do so is usually an exercise in futility.

Because:

Nameservers have no set order in which they return information; the specific information returned for a lookup should be all records, but in no particular order; what you type in first has no relationship to what gets served first, and each request generally is served in a different order.

All the records are returned, but most resolvers have no way to handle multiple answers, as the relevant RFCs only require one response. So there's no way to guarantee a given reverse DNS response will be sent, received, or matched.

As Daredevil points out, and as I can verify, both .nl and .eu require only that there be at least two working DNS servers (perhaps on different subnets; I haven't checked this recently) and working reverse DNS for the IP#s returned by the forward (normal) DNS resolution.

The working reverse DNS should point to a domain/subdomain/hostname/service name that does have it's own forward DNS, but it doesn't have to have any connection with the original domain.

Have I managed to confuse this even more?



Jeff

Many resolvers only allow one domain name to be resolved for a pointer

 

[jdlitson]

It's always good to hear from you Jeff.
I enjoyed the history lesson on ARPA.
No, you didn't confuse me; you are a very big help.

Thanks,

Jason