bind: how to add a forwarding zone with overriding?

Question

on my intranet dns server, want to override some addresses.

So basicially, it should forward all resolving requests for the zone mydomain.tld, that are not in the "/etc/named/mydoamin.tld" file to the real DNS servers...

zone "mydomain.tld" IN {
    type master;
    file "/etc/named/mydomain.tld";
    forwarders { 1.1.1.1; 2.2.2.2; 3.3.3.3; };
    forward only;
};

how can this be done?

---

Clarification:

In the file "/etc/named/mydomain.tld" there are - for example - a cupple of records:

abc.mydomain.tld.      IN    A 192.168.1.2
def.mydomain.tld.      IN    A 192.168.1.3
ghi.mydomain.tld.      IN    A 192.168.1.4
jkl.mydomain.tld.      IN    A 192.168.1.5

and - for example - this records are (not in the file "/etc/named/mydomain.tld" but) in the offical nameservers:

abc.mydomain.tld.      IN    A 123.123.123.123
www.mydomain.tld.      IN    A 123.123.123.123
mail.mydomain.tld.     IN    A 123.123.123.123

so when a client in the intranet asks the intranet nameserver, the namesever should first look at his definitions and then in the case the entry is NOT sepcified, he should ask the official nameservers.

if the client asks for abc.mydomain.tld. the intranet nameserver should return 192.168.1.2...

and if the client asks for www.mydomain.tld. the intranet nameserver should return 123.123.123.123...

Answer 1

You cannot do this. Each DNS server must either contain a complete copy of the DNS zone, or have the entire DNS zone forwarded to the other server. You cannot have bits and pieces on different servers (unless you create sub-zones and delegate using NS records, but I digress).

So either make your internet and intranet servers the same, or forward one to the other like so:

zone "mydomain.tld" IN {
    type forward;
    forwarders { your-other-server-here; };
};