Most enterprises in the early IT infrastructure will consider a mix of infrastructure services and domain control roles such as DHCP deployment. This will not only save costs but also simplify management.
But as the size of the enterprise expands and the IT infrastructure becomes more and more sophisticated, the mix of deployments can be limited in terms of rights management and usability. Separating the role server is definitely the best choice.
Let's look at how to migrate the DHCP server in Windows2008 R2 domain control to Windows 2012 and implement DHCP failover functionality.
A new feature of the DHCP failover Windows2012, which provides the ability to provide two DHCP servers with IP address and option configuration for the same subnet or scope, provided that the DHCP service is continuously available to clients. Two DHCP servers replicate the lease information between them, and when one server is unavailable, another server can assume responsibility for serving clients across the subnet. You can also configure failover in a load-balancing configuration using client requests that are distributed between two servers in a failover relationship.
For more information about Windows DHCP
Http://technet.microsoft.com/zh-cn/library/jj200226.aspx
Environmental preparedness
Windows 2008 R2
ip:192.168.1.10
Server nmae:windows2008
Service status:active Directory, DNS, DHCP
Windows Server 2012
ip:192.168.1.20
Server NMAE:DHCP01
Service STATUS:DHCP
Windows Server 2012
ip:192.168.1.21
Server NMAE:DHCP01
Service STATUS:DHCP
Windows 2008 R2 Server Status
There are two scopes available at the DHCP server