Create a database availability group network in Exchange Server
You can use the EAC or the Exchange Management Shell to create a DAG network.
Looking for other management tasks related to DAGs? Check out Manage database availability groups.
What do you need to know before you begin?
Estimated time to complete: 1 minute
You need to be assigned permissions before you can perform this procedure or procedures. To see what permissions you need, see the "Database availability groups" entry in the High availability and site resilience permissions topic.
You can create a DAG network only when automatic network configuration has been disabled for a DAG. For detailed steps about how to disable automatic network configuration for a DAG, see Configure database availability group properties.
When creating a DAG network, you must assign unique subnets that aren't in use by another DAG network. If you use subnets that are assigned to an existing DAG network, they will be removed from that DAG network and added to the newly created DAG network.
For information about keyboard shortcuts that may apply to the procedures in this topic, see Keyboard shortcuts in the Exchange admin center.
Tip
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Use the EAC to create a database availability group network
In the EAC, go to Servers > Database Availability Groups.
Select the DAG you want to configure, and then click
.On the new database availability group network page, provide the following information:
Database availability group network name: Use this field to type a name for the network that's unique in the DAG.
Description: Use this field to provide a text description of the DAG network.
Subnets: Use this field to associate one or more subnets with the DAG network. Click
to add a subnet, click 
to edit a subnet, and click minus (-) to remove a subnet.
Click Save to create the DAG network.
Use the Exchange Management Shell to create a database availability group network
This example creates the network ReplicationDagNetwork02 with a subnet of 10.0.0.0 and a bitmask of 8 in the DAG DAG1. Replication is enabled for the network, and an optional description of the network is also being added.
New-DatabaseAvailabilityGroupNetwork -DatabaseAvailabilityGroup DAG1 -Name ReplicationDagNetwork02 -Description "Replication network 2" -Subnets 10.0.0.0/8 -ReplicationEnabled:$True
How do you know this worked?
To verify that you've successfully created a DAG network, do one of the following:
In the EAC, navigate to Servers > Database Availability Groups. Select the appropriate DAG, and the newly created DAG network is displayed in the details pane.
In the Exchange Management Shell, run the following command to verify the DAG network was created and to display DAG network configuration information.
Get-DatabaseAvailabilityGroupNetwork <DAGNetworkName> | Format-List
For more information
Set-DatabaseAvailabilityGroupNetwork
Get-DatabaseAvailabilityGroupNetwork