How do I setup multiple DHCP ranges for a single office?

I need to setup a lab network in our office that are on a different range of IPs. How do I distinguish the computers on the lab network from our corporate network so that the DHCP server knows to give these a different IP?

Our DHCP server is running Windows Server 2008

Assuming you are using different VLANs, you can use ip helper in Cisco switch to configure a DHCP relay. Then you can distinguish the relayed clients in the DHCP server (by using GIADDR) and give them different addresses. See: http://routergod.com/trinity/ and http://www.cisco.com/en/US/docs/switches/lan/catalyst3750/software/release/12.2_25_sec/configuration/guide/swdhcp82.html#wp1096758 and RFC 3046

You question asks other questions but essentially you just need to;

• define a second scope that's appropriately routed where required,
• then expose that scope onto either a separate vlan, segment (via a specific NIC) or fill it with specific reservations for the lab machines so that it's not used for anything else.

Oh and the MS DHCP service lets you have multiple scopes on a single service without the need for any additional licences.

If you don't want to go the "create VLAN" route:

A workaround is to simply put all lab boxes behind another router/firewall with built-in NAT and DHCP, like a home gateway, etc. Now all lab boxes are segmented from production, still have Internet through production network, but can do their own broadcast traffic (i.e. DHCP) without bothering the production network.