Steps to Configure a DAG array in Exchange 2010

Here is the steps in Powershell  to create a DAG, configure the DAG networks and assign the DAG to a CAS array.  Make sure all mailbox servers are on the same subnet.  Also in my example I have 2 network cards per mailbox server one for MAPI traffic and another for Replication.  Everything in BLUE is what needs to be changed for your environement

Create DAG (Using a Hub Transport for a Witness server is pretty standard practice)

1.1.    From Powershell  New-DatabaseAvailabilityGroup –Name "DAG" –WitnessServer “server” –WitnessDirectory c:\DagWitness\Dag –DatabaseAvailabilityGroupIPAdresses x.x.x.x

2.       Add Mailbox Servers to DAG

2.1.    From Powershell Add-DatabaseAvailabilityGroupServer –Identity Dag –MailboxServer Servername

3.       Configure DAG Network Settings

3.1.    From PowerShell Set-DatabaseAvailabilityGroupNetwork –Identity Dag\DAGNetwork01 –Name “MAPI” –Subnets X.X.X.X/24 –ReplicationEnabled $false

3.2.    From Powershell Set-DatabaseAvailabilityGroupNetwork –Identity Dag\DAGNetwork02 –Name “Replication” –Subnets X.X.X.X/24 –ReplicationEnabled $True

4.       Configure MailBox serves with CAS Array

4.1.   From Powershell  Get-MailboxDatabase –server “Servername” | Set-MailboxDatabase –RpcClientAccessServer "CAS ARRAY NAME"

By doing the above steps you will have a DAG configured and all mailboxes you created will automatically be assigned to the CAS Aray.