Windows DHCP Server Redundancy can be obtained by using one of the following options:
1. DHCP Failover – Using Windows Clustering technology
DHCP Step-by-Step Guide: Demonstrate DHCP Failover – Clustering in a Test Lab
* Supporting by Windows Enterprise/Datacenter edition and required a shared storage.
* Supporting by Windows 2008 R2.
3. Setup two DHCP servers with non-overlapping DHCP scope.
4. Manually export/import DHCP settings to a stand by server.