One major update is the support for Windows 2012R2 and with it support for Failover Clusters without AAP’s (Administrative Access Points). A cluster without AAP is a cluster with out a IP address, DNS entry and Cluster name object. In windows 2012R2 an AAP cluster can be created via Powershell only.
Exchange 2013 Supports creating a DAG Cluster without an AAP. The DAG can be created via Powershell or the Exchange EAC.
Creating a DAG without an AAP Is simpler and more Sucure as the Dag (Cluster) does not have an IP Address, DNS entry or Active Directory object associated with it.
In the EAC, the process is the same as creating a regula DAG, you just configure the DAG with an IP address of 255.255.255.255
Using Powershell you create the DAG using New-DatabaseAvailabilitygroup and use a specific syntax for the DatabaseAvailabilityGroupIPAddresses parameter. For example:
New-DatabaseAvailabilityGroup –Name D2 –WitnessServer ex3.e15demos.com -DatabaseAvailabilityGroupIPAddresses ([System.Net.IPAddress])::None
Another benfit of Using Windows Server 2012 R2 For an Exchange 2013 deployment is that it includes most of the required preq’s and there is no need to install any aditional software before deploment except for the Office 2010 Filter pack and the UCMA package.
Take into account that creating a DAG without an AAP is optional, thought it is much easier to administrate and maintain. I would recommend that you check before deployment that 3rd party applications such as backup and monitoring applications fully support the new Cluster mode.
I would also like to refrence Scott Scnoll’s blog on the subject. This was also the only place that I could currently find refrences to creating a DAG with out an AAP as the technet documentation does not seem to mention it yet.