Configuring a domain slave to look up subdomain hosts

[Mike Bernhardt]

I have a domain and a subdomain which is delegated by the

I am trying to figure out the correct way to have the slave of a parent
domain look up hosts in a subdomain managed by others. I'm running BIND
9.8.1-P1. The current working configuration for the subdomain is this:

options {
        directory "/var/named";
        allow-recursion { any; };
        allow-query { any; };
        allow-query-cache { any; };
        forwarders { 148.165.3.10; };
        forward only;
        recursive-clients 2000;
        zone-statistics yes;
};

zone "domain.com" {
        type slave;
        masters { 10.130.1.30; };
        file "db.domain";
        forwarders { };
};

But using "forwarders" doesn't seem like the correct way to do it. It's in
the options in order to forward internet queries to our external name server
instead of to the root servers, which aren't accessible from inside. I've
been messing with stub zones but that doesn't seem to work:

zone "domain.com" {
        type slave;
        masters { 10.130.1.30; };
        file "db.domain";
};
zone "subdomain.domain.com" {
        type stub;
        masters { 10.2.241.101; 10.2.242.222; };
        file "db.subdomain";
};

With this configuration, the zone file for subdomain.domain.com is correctly
created but when I run tcpdump I can see that queries for
host.subdomain.domain.com are being forwarded to 148.165.3.10, not to the
subdomain name servers. The result of course is NXDOMAIN.

With forwarders set for the zone domain.com, the slave queries the zone
master, which then queries the subdomain name server as it should. So the
stub zone is apparently being ignored.

What is wrong? Perhaps I'm misunderstanding the purpose of stub zones? Let
me know if you need additional config details.