Subject: DNS lookup for internal adresses
To: None <>
From: David TAILLANDIER <>
List: netbsd-users
Date: 03/07/2002 23:18:34
We have a LAN of several computers connected to the internet via a 
NetBSD gateway. We don't have any DNS ; We only use our provider's DNS 
to resolve internet adresses. 
Our local network is 
Nothing special as you can see.

Our internet provider have recently made a change to its DNS, and I 
found it because... there is a problem now :-)
Their DNS *seems* to not answer anymore to reverse lookup requests like 
"how is ?". Since this change, when I log onto the 
NetBSD gateway via SSH, it took several seconds before I can enter my 
password because the NetBSD box wait the name of the computer I use 
(and, since the provider's DNS drops requests for ...). 
And when I logged in, it tooks several seconds before a simple ping to 
internal network to start.   ping 192.168.0.x   for example.

I think NetBSD send reverse lookup requests for every of thoses cases 
and I have to wait for timeout. Around 2 minutes (!).

I then modified nsswitch.conf to explain NetBSD I don't want it to ask 
anything to the DNS ("host: file" instead of "host: file dns"). 
All this because I very new into *nix familly. 
Of course, I can't use DNS resolution anymore on the NetBSD box.

How can I tell the NetBSD box to use DNS reverse lookup only for 
"real" internet adresses ? 
Not for or (or what I want in fact because 
we have some other LANs connected via 'vtun').

where can I find any documentation because it seems to be very hard to 
find something written about NetBSD (or I'm too dumb to find it).

Many thanks from France   :-)