Explanation/Reference:
Explanation:
Windows Server 2012 DHCP provides a new high availability mechanism addressing these critical aspects. Two DHCP servers can be set up to provide a highly available DHCP service by entering into a failover relationship. A failover relationship has a couple of parameters which govern the behavior of the DHCP servers as they orchestrate the failover. One of them is the mode of the failover operation - I will describe this shortly. The other is the set of scopes that are part of the failover relation. These scopes are set up identically between the two servers when failover is configured. Once set up in this fashion, the DHCP servers replicate the IP address leases and associated client information between them and thereby have up-to-date information of all the clients on the network. So even when one of the servers goes down - either in a planned or in an unplanned manner - the other DHCP server has the required IP address lease data to continue serving the clients.
There are two modes of configuring DHCP failover to cater to the various deployment topologies: Load balance and Hot Standby. The Load Balance mode is essentially an Active-Active configuration wherein both DHCP servers serve client requests with a configured load distribution percentage.