ask to an other dns server (same domain name)

[Kevin Darcy]

Xavier Callejas wrote:

>Hi.
>
>This is my case.
>
>My ISP is hosting my company domain eg: mydomai.com dns internet dns service 
>is hosted in their server. But locally here in my lan I hav a dns server 
>(fedora c3) hosting the same domain: mydomain.com with its private ips 
>reverse zone, dhcpd acualize the zone dinamically. But the smtp and pop3 
>servers that I use are the same of my ISP (I don't have pop3 and smtp servers 
>here y my lan), so pop.mydomail.com doesn't exist in my lan, but how can I do 
>for my dns local sever ask to another dns server for a record of the same 
>domain????
>
>like this: a pc ask por pop.mydomail.com to my local dns server, my local dns 
>server don't know about a pop.mydomain.com but it asks to my isp dns server 
>for a pop.mydomail.com in their mydomain.com zone, if it exist in their zone 
>turn back the ip.
>
This kind of "forward on NXDOMAIN" forwarding is not supported within 
BIND. If a nameserver is authoritative for a zone, it believes it knows 
everything about that zone and will not forward any queries for names in 
the zone.

Your only choices would be to a) delegate the names in question as 
subzones (this would have to be done in co-ordination with your ISP) 
which you can then forward, or b) duplicate the names in the internal 
version of your zone.

                                                                         
                                    - Kevin