Need help on delegation to subdomain/external servers

[Adam Tkac]

On Wed, Sep 16, 2009 at 05:20:21PM +0200, RUOFF LARS wrote:
> Hi,
> 
> i'm using BIND9 on an Ubuntu-8.10-server.
> I'd like to configure the following:
> For a given name (eg. vega.lab.ts), I'd like to forward the request to
> two external DNS servers, *simultaneously*, and respond with the first
> response that i get.
> 
> Is this possible?
> I didn't see how to do it directly, so i tried using a subdomain, (eg.
> x.vega.lab.ts) and specifiying the two DNS for this subdomain:
> 
> Extract from the lab.ts zone file:
> [...]
> x.lab.ts.       IN      NS      vega-a.x.lab.ts.
> x.lab.ts.       IN      NS      vega-b.x.lab.ts.
> vega-a.x.lab.ts.        IN      A       172.25.32.252
> vega-b.x.lab.ts.        IN      A       192.168.2.3
> [...]
> 
> But this doesnt seem to work:
> named-checkzone lab.ts /etc/bind/db.lab.ts says:
> zone lab.ts/IN: x.lab.ts/NS 'vega-a.x.lab.ts' (out of zone) has no
> addresses records (A or AAAA) zone lab.ts/IN: x.lab.ts/NS
> 'vega-b.x.lab.ts' (out of zone) has no addresses records (A or AAAA)
> zone lab.ts/IN: loaded serial 2 OK
> 
> How can i do it?
> Thanks,
> Lars

You can use `forward` zone. Check
https://www.isc.org/software/bind/documentation/arm95#zone_statement_grammar:

zone "example.com" IN {
	type forward;
	forward only;
	forwarders { IPaddr; };
};

Regards, Adam

-- 
Adam Tkac, Red Hat, Inc.