Map virtual networks in different Azure regions

This article describes how to map two instances of Azure Virtual Network located in different Azure regions with each other. Network mapping ensures that when a replicated virtual machine is created in the target Azure region, the virtual machine is also created on the virtual network that's mapped to the virtual network of the source virtual machine.

Prerequisites

Before you map networks, ensure that you have created an Azure virtual network in both the source region and the target Azure region.

Map virtual networks

To map an Azure virtual network that's located in one Azure region (source network) to a virtual network that's located in another region (target network), for Azure virtual machines, go to Site Recovery Infrastructure > Network Mapping. Create a network mapping.

Network mappings window - Create a network mapping

In the following example, the virtual machine is running in the East Asia region. The virtual machine is being replicated to the Southeast Asia region.

To create a network mapping from the East Asia region to the Southeast Asia region, select the location of the source network and the location of the target network. Then, select OK.

Add network mapping window - Select source and target locations for the source network

Repeat the preceding process to create a network mapping from the Southeast Asia region to the East Asia region.

Add network mapping pane - Select source and target locations for the target network

Map a network when you enable replication

When you replicate a virtual machine from one Azure region to another region for the first time, if no network mapping exists, you can set the target network when you set up replication. Based on this setting, Azure Site Recovery creates network mappings from the source region to the target region, and from the target region to the source region.

Configure settings pane - Choose the target location

By default, Site Recovery creates a network in the target region that is identical to the source network. Site Recovery creates a network by adding -asr as a suffix to the name of the source network. To choose a network that has already been created, select Customize.

Customize target settings pane - Set target resource group name and target virtual network name

If network mapping has already occurred, you can't change the target virtual network when you enable replication. In this case, to change the target virtual network, modify the existing network mapping.

Customize target settings pane - Set the target resource group name

Modify network mapping pane - Modify an existing target virtual network name

Important

If you modify a network mapping from region A to region B, ensure that you also modify the network mapping from region B to region A.

Subnet selection

The subnet of the target virtual machine is selected based on the name of the subnet of the source virtual machine. If a subnet that has the same name as the source virtual machine is available in the target network, that subnet is set for the target virtual machine. If a subnet with the same name doesn't exist in the target network, the alphabetically first subnet is set as the target subnet.

To modify the subnet, go to the Compute and Network settings for the virtual machine.

Compute and Network compute properties window

IP address

The IP address for each network interface of the target virtual machine is set as described in the following sections.

DHCP

If the network interface of the source virtual machine uses DHCP, the network interface of the target virtual machine is also set to use DHCP.

Static IP address

If the network interface of the source virtual machine uses a static IP address, the network interface of the target virtual machine is also set to use a static IP address. The following sections describe how a static IP address is set.

Same address space

If the source subnet and the target subnet have the same address space, the IP address of the network interface of the source virtual machine is set as the target IP address. If the same IP address is not available, the next available IP address is set as the target IP address.

Different address spaces

If the source subnet and the target subnet have different address spaces, the next available IP address in the target subnet is set as the target IP address.

To modify the target IP on each network interface, go to the Compute and Network settings for the virtual machine.

Next steps