RD flag for per-domain forwarding

[Carlos Peon Costa]

I'd like to share this scenario:

* Domain "example.org" is hosted on name server 1.1.1.1
* This domain has a subdomain "my.example.org" delegated to 2.2.2.2
through regular NS glue records
* To allow my bind nameserver know "example.org" domain I set a
per-domain forwarding:
  zone "example.org" { type forward; forwarders { 1.1.1.1; }; };

I've found that if I query "my.example.org" to my bind nameserver it
forwards the query to the appropriate nameserver 1.1.1.1 *with* the RD
flag, but if 1.1.1.1 has no connection with 2.2.2.2 the query will
fail. The point is that if the RD flag were disabled 1.1.1.1 would
reply with the authoritative nameserver 2.2.2.2 and bind could reach
this one and solve the query.

RD flag must be set for global forwarders but I'm wondering if it
makes sense to add a configuration option to allow set/unset RD flag
in per-domain forward configurations.

Regards,
Carlos.