DHCP Failover is new feature introduced in server 2012 and I would say it’s one of the best features in Server 2012. It provides high availability for DHCP services and also it can load balance the DHCP requests. We will see how to configure this feature. If you wish to try this on your Lab make sure you have one more additional server is setup with DHCP role.
I am assuming that that your second server is ready with just DHCP role is installed.
1) First you need to open DHCP server console on the first server and right click on any of the scope and then choose “Configure Failover”.
2) On the first window make sure that all the scope are selected. Then proceed Next.
3) Then enter the FQDN of your second DC (Here its DC1.test.local well my primary one is DC2.test.local)
4) After validation you will see a window as below.
- Here Maximum Client Lead Time is set as 10 minutes (It’s acceptable in lab environment but in production you should consider longer interval, default is 1 hr)
- Mode can be defined either Load Balance or Hot Standby. Meaning either both active or active/passive mode.
- Also you need to provide a Shared Secret (Password) to authenticate the failover between DHCP servers.
5) When you press finish you will see box as below which will automatically configure these settings for you and up on completion you will see successful message as well.
6) After this, logon to the second server and Authorize that DHCP server for a seamless DHCP failover.