I’m currently studying for the 70-414 exam and following the course provided by pluralsight.com. I’ve been following the videos on setting up a Hyper-V cluster using System Center Virtual Machine Manager 2012 R2.
When I got to the step of creating the cluster it was failing in my demo lab. I kept getting this error:
Error (25325) The cluster creation failed because of the following error: Network 172.16.2.0/24 has already been specified.
The 172.16.2.0 network was dedicated to the iSCSI connections. I had configured two NICs on the same subnet, connected to a VM running Windows 2012 R2 iSCSI target with MPIO. It turns out VMM does not like having multiple adapters on the same subnet. Once one of the two adapters were disabled on both hosts, the cluster creation was successful. The adapters can be enabled again after cluster creation.