Thanks for the replies.

I have a few different situations in which I'm trying to set this up, but I'll give a more concrete example: my parent's network connecting to my network via OpenVPN.

I have a network in 192.168.20.0/24 and my parents are in 192.168.2.0/24 and OpenVPN connects both sites over DSL lines. I run my own DNS server for internal name resolution with my internal domain being myplace.priv. My parents have a DNS server and their internal domain is parents.priv. I'd like for them to be able to resolve intranet.myplace.priv as well as parentnet.parents.priv using just the hostname. For example, if they type: http://intranet into Firefox, they should ideally get to intranet.myplace.priv as long as the OpenVPN connection is up. In the event that it's down, I don't mind if they can't get there. But I'd still like them to be able to access their own site at http://parentnet.

The problem I've run into in the past is that they've needed to use the FQDN to access resources on my network if I set their 'search' option as 'search parentnet.parents.priv' or as the case may be, have DHCP push that out. And this is what I'm asking for... a way for the query to fail within one domain and pass onto the next before heading out the door to the ISP DNS server (where it should fail as well since this is all private internal stuff). Ideally, if they ask for http://intranet and that host or alias only exists in my domain, then it should fail for their domain. So maybe the search order matter first? I'm still not sure if I'm explaining this clearly. I just really want to avoid having to pull them into my domain. But maybe that's the way to go with them as a secondary to my master...