I'm a Linux guy, but here at work we're basically re-doing our entire network and going to Active Directory. I'm trying to get Windows Small Business Server 2008 set up, and one of the problems I'm encountering is with the DHCP server.
We have 3 WAN connections. I want to take those three connections, plug them to our SonicWALL device, and from there each connection to a separate NIC on the SBS2008 server. Then I need the DHCP server to issue IP addresses in different subnets (192.168.10.0, 192.168.20.0, 192.168.30.0) depending on which NIC card the connection comes in on.
I need to allow these three subnets to communicate to the domain controller but NOT be allowed to communicate between the subnets. Those on 192.168.10.0 shouldn't be able to ping devices on the 192.168.20.0 and 192.168.30.0 subnets.
So you'll want to define 3 separate scopes:
192.168.10.0 with nic 1 as the gateway 192.168.10.1
192.168.20.0 with nic 2 as the gateway 192.168.20.1
192.168.30.0 with nic 3 as the gateway 192.168.30.1
I'm assuming you'll probably use /24 subnets, but it doesn't really make a difference as long as they don't overlap. Since it's a Small business server and the DCHP server is also the AD server there should be no issues with the different connections getting to AD. I don't believe the different interfaces will be able to talk to each other, but I don't currently have a free test environment to verify with right now.