Explanation/Reference:
Explanation:
You need to ensure that replication only occurs over the replication network.
If you would like to 'force' replication to only go over the Replication Network, then you definately would like to disable replication on the MAPI Network, but IF the NIC on the Replication Network goes down, it will start replicating over the MAPI NIC.
There is no way of blocking that behaviour and isn't what you'd want anyway since DAGs actually cope quite fine with just 1 NIC.
DAG Networks
Each database availability group (DAG) network has several properties that you can configure, including the name of the DAG network, a description field for the DAG network, a list of subnets that are used by the DAG network, and whether the DAG network is enabled for replication.
You can configure a DAG network only when automatic network configuration has been disabled for a DAG.
There are specific networking requirements that must be met for each DAG and for each DAG member.
Each
DAG must have a single MAPI network, which is used by a DAG member to communicate with other servers (for example, other Exchange 2013 servers or directory servers), and zero or more Replication networks, which are networks dedicated to log shipping and seeding.
MAPI
MAPI stands for Messaging Application Programming Interface, and it gives programs the ability to send email using your email program to do the actual sending.
Set-DatabaseAvailabilityGroup
The Set-DatabaseAvailabilityGroup cmdlet enables you to manage DAG properties that can't be managed from the Exchange Administration Center (EAC), such as configuring network discovery, selecting the TCP port used for replication, and enabling datacenter activation coordination (DAC) mode.
Set-DatabaseAvailabilityGroupNetwork
Use the Set-DatabaseAvailabilityGroupNetwork cmdlet to configure a network for a database availability group (DAG).
You can configure a variety of network properties, such as the name for the network, a description of the network, a list of one or more subnets that comprise the network, and whether the network is enabled for replication (log shipping and seeding).
You need to be assigned permissions before you can run this cmdlet. Although all parameters for this cmdlet are listed in this topic, you may not have access to some parameters if they're not included in the permissions assigned to you.
B: Disables replication over the MAPI network as required in this scenario C: Ensures that you can configure a DAG network by turning the automatic configuration off.
The ManualDagNetworkConfiguration parameter
Specifies whether DAG networks should be automatically configured. If this parameter is set to False, DAG networks are automatically configured. If this parameter is set to True, you must manually configure DAG networks.
References: