DHCP failover in Windows Server 2012 allows the deployment of a fail-safe DHCP server structure without a cluster. DHCP failover supports two servers with IPv4 configurations. The servers can also be members of a workgroup; domain membership is not strictly necessary.
The DHCP failover feature lets you provide two DHCP server IP addresses and option configurations on the same subnet or in the same range. This information is replicated between the two DHCP servers. Configuring the failover to load-balancing, in which client requests are distributed to the two servers, is also possible.
Open the DHCP console on the DHCP server, right-click the DHCP realm in which you want the fail-safe, and then click Configure Failover . On the second page, enter the Partner Server and then click Next . You can also specify a common secret key for this failover relationship. You can also select the mode with which you want to use the fail-safe: either load balancing or hot standby. By default, Load Balance is selected. This means that two servers share the requests. After you have completed the setup, you can view the failover in the Failover tab of the IP range's properties.