Split PTR zone (internal and external)

Kevin Darcy kcd at chrysler.com
Thu Jul 28 21:58:22 UTC 2011


On 7/28/2011 12:26 PM, CT wrote:
> I am wondering what might be a good "workaround" for this
> legacy setup...
>
> Will do my best to explain..
>
> IP Space
> - 1 Class B Global Unique (used Externally and Internally)
> - 1 Class B RFC1918
>
> DNS Setup
>
> External DNS     (Linux - Bind 9.8.x)
> - example-ext.com     DNS domain
> - authoritative for PTR Global Unique
>
> Mid Teir DNS      (Linux - Bind 9.8.x)
> - Mixture of Class B Global and RFC 1918
> - not accessible "from the Internet"
> - forwards all RFC 1918 PTR to the Internal DNS
> - can resolve any Internal / External A records
>
> Internal DNS        (MS DNS - w/DDNS)
> - only internal DNS zones (i.e. inside.example.com)
> - MS DNS use Mid Tier DNS for "external" name resolution (i.e. isc.org)
> - Has the *same* Global Unique Class B PTR as the External DNS
> **********************
>
> Scenario
>
> - internal hosts using the Internal DNS can not resolve  External PTR
> for example-ext.com. since a valid PTR zone already exists..
>
> The only solution that I have come up with is to manually
> put the "external" PTR records in the AD PTR Zone file.
>
> Not sure if there is a resolution to do in MS DNS but will ask the same
> question in that group.  Wanted to start here..
Delegate out the relevant /24 ranges as subzones of your main /16 
in-addr.arpa zone. Define only the internal reverse subzones in your 
"Internal DNS" and then use slave/stub/forward to resolve all of the 
external ones.

                                                                         
                                 - Kevin




More information about the bind-users mailing list