I'm putting together a small active directory implementation for a buddy of mine. I currently have 2 servers (one is the primary domain controller) and a couple clients. I need to test and run updates on every machine on this domain, but I would have plug them into my current LIVE domain to get it internet access. From what I've read having two separate domains on a single subnet is a bad idea (even though it is temporary) so I don't want to risk messing anything up on my production domain.

I'm pretty sure I can create a separate VLAN on my extreme 48 port switch and plug this smaller domain into it on a different subnet, but I don't know the commands. Both subnets would need internet access of course (one of the things I can't wrap my head around is routing internet traffic between subnets (gateway is on production subnet).

My production domain is on subnet 192.168.200.0.
My new domain I want to put online would go into subnet 192.168.10.0.

A shove in the right direction would be greatly appreciated. Thank you!