We have a network on 192.168.x.0/24 and we have recently set up a separate standalone network.
Whilst the standalone network was being set up it was permissible and indeed necessary to connect to the web and our other network and we connected a switch on each network to one another. In order to get routing between the networks we manually configured all machines on what would become the standalone network to use 192.168.x... and this worked fine.
We have now completed the set up, the network is in use and it is no longer permissible to connect the standalone network beyond itself. It must remain completely isolated. We're now using DHCP 192.168.y.0/24 for this network.
If in the future, it is necessary (although I'd be breaking the rules!) to get a connection to our main network I would again connect a switch on each network. But I would have no routing between them - is this a correct assumption?
1) How would I go about setting up a temporary route that would allow the standalone network to reach outside itself, but not for the outside to reach in?
2) How would I demonstrate that no-one on our main network could detect the presence of the standalone network whilst this routing was in place?
Both networks are domains using W2K3 as DC's.
I'm sure that this is an easy question for somebody, but I think it warrants top points!