[Dnsmasq-discuss] DNSMasq script lookup

[Nicholas Weaver]

On Mar 29, 2012, at 12:12 PM, richardvoigt at gmail.com wrote:

>> 
>> On thing which might be interesting, is to define a new type of upstream server (maybe called a look-aside server) which dnsmasq will send a query to first, and which if it can't answer the query can return a custom return-code "Not known", which causes dnsmasq to then push the query into the standard server pathway.
> 
> How's this help?  Hasn't dnsmasq thrown away the information it would need to send the query to a second server at this point?

You don't have it return the custom return code, you have it return the question unchanged.

Now its just "go onto the next server", as the table entry is still sufficient to route the reply to the final destination, and because it returned the unmodified question, DNSMasq will have the information needed to forward the question onward.