Avoiding side effects of the forwarding

[Andrey G. Sergeev (AKA Andris)]

Hello,


I'm trying to avoid one annoying side effect from the forwarding queries 
for some private TLDs to their authoritative servers. Here is the 
disposition.

1. There is a private TLD "private-tld." served by 192.168.28.1 and 
192.168.28.2;

2. The 192.168.28.1 and 192.168.28.2 servers are authoritative for both 
the "legitimate-zone.private-tld." *and* the "private-tld." zone.

3. I want to be able to resolve hostnames in 
"legitimate-zone.private-tld." but I have no direct DNS access to and 
even any network connectivity with the 192.168.28.1 and 192.168.28.2 
boxes. However there is a local DNS server available which *has* an 
ability to communicate with these private hosts. I configure my local 
server like this:

--- named.conf on the forwarding box ---
zone "legitimate-zone.private-tld" IN {
	type forward;
	forward only;
	forwarders {
		192.168.28.1;
		192.168.28.2;
	};
};
--- named.conf on the forwarding box ---

Using this the forwarding server will got and store in its cache the 
authority RRs for the "private-tld." just after the first attempt to 
resolve names such as "ftp.legitimate-zone.private-tld.". Within the TTL 
timeframe any subsequent queries for the *nonexistent* names like 
"hostname.nonexistent-zone.private-tld." will be also directed to the 
192.168.28.1 and 192.168.28.2. This can be annoying and even undesirable.

Is there a way to setup the forwarding server to ignore the authority 
RRs beyond the forwarding scope?


-- 

Yours sincerely,

Andrey G. Sergeev (AKA Andris)     http://www.andris.name/