Bind9 - Same Domain - Forward querries if not found in internal DNS

Question

I have some servers with IP public and Private IP and domain exemple.com hosting on external DNS with a lot of entries

server1 IN A IpPublic
server2 IN A IpPublic
server3 IN A IpPublic
server4 IN A IpPublic
...
...

I want to set up an Internal DNS for use the localIP but when the internal DNS cant resolv something then use the externalDNS

server1 IN A PrivateIP
server2 IN A PrivateIP
server3 IN A PrivateIP

I have created a zone

zone "exemple.com" {
type master;
file "/etc/bind/db.exemple.com";
allow-query { any; };
};

and forwarders

 forwarders {
        8.8.8.8;
        8.8.4.4;
 };

as my internal DNS is master of exemple.com he didn't forward in any case querries with *.exemple.com to my external DNS .

How I can setup bind9 for forward querries if bind9 didnt find the entry in /etc/bind/db.exemple.com

thanks a lot

Answer 1

No, I don't believe you can get BIND to do that by adding an authoritative (master/slave) zone.

You may want to consider delegating a sub-zone for your "local" needs, alternatively use RPZ on your resolver server as a means of overriding lookups that would normally be looked up through recursion (or forwarding).