Azure Hybrid & Cloud Migration Blog

Setting up Exchange Disaster Recovery and Site Resilient setup by stretching Exchange Database Availability Group (DAG) across different Active Directory sites would require proper network infrastructure in place. This network infrastructure has two sides to it, in the first phase you have to configure layer 1 connectivity between primary Exchange mailbox servers and secondary or DR site Exchange Servers. Once you have the network connectivity established then the second phase starts, in which we have to configure the routing of Exchange DAG replication network between Exchange Mailbox Servers.

For setting up routing between Exchange DAG Mailbox Servers, I recently published a blog post “Configuring Exchange 2010 Replication Network for Remote DR Exchange DAG Mailbox Servers”. In this article I explained step by step procedure you have to take to configure routing between primary and secondary site Exchange Mailbox Servers.

In the third and last phase of configuring Exchange DAG networks for your Exchange Disaster Recovery and Site Resilient setup, we have to adjust the Exchange DAG network settings within Exchange Server. Before we hit and understand the steps required to adjust Exchange DAG networks for DR Exchange replication network, we will take below replication network example for Contoso Corporation:

Now when you will add the additional MBXDR1 and MBXDR2 in the existing Exchange DAG (Database Availability Group) as DAG members, so you would see two new DAG networks will be created with the name of DAG Network 1 and DAG Network 2.

These two new DAG network would include the networks from MBXDR1 and MBXDR2 for their replication network interfaces.

As a recommended and best practice to configure DAG networks for primary and secondary DAG Exchange Mailbox Server, we should go to existing MAPI network and add DR Exchange Server Replication Network, for example as per below DAG network image we would add the “10.XXX.35.0/24” network into the MAPI network, which would automatically will add the required interfaces into the MAPI network interfaces area. Then we will also add the “10.XXX.84.0/24” network into the Replication Network which is enabled for DAG continues replication.

After performing the above outlined steps of adding / merging the MAPI and Replication network into the existing created MAPI and Replication sets, your DAG network should look like the below image:

I hope this example would help you to configure your DAG network in a best of possible manner.

Cheers!