Users can seamlessly link multiple virtual networks by utilizing virtual network peering in Azure. This integration enables the networks to operate as a single entity for connectivity. When virtual machines interact across peered virtual networks, they leverage Microsoft’s backbone infrastructure for communication. Consequently, traffic is directed through Microsoft’s private network, similar to how traffic between virtual machines within the same network is handled.
Azure supports the following types of peering:
Virtual network peering: Enable the connectivity for the virtual networks within the same Azure region.
Global virtual network peering: Enabling the connectivity of virtual networks across different regions in Azure.
If you need to resize the address space of your Azure virtual network after scaling your workloads, you can do so without any downtime on the currently peered address space. This helpful feature applies to both IPv4 and IPv6 address spaces. However, once you resize the address space, peers must sync with the new changes in the address space. Virtual network peer sync can be done through the Azure portal or with Azure PowerShell. Azure recommends running sync after every resize address space operation instead of performing multiple resizing operations and then running the sync operation.
You can resize addresses in the following ways:
- Modify the address range prefix of an existing address range. For example, change 10.0.0.0/24 to 10.0.0.0/23.
- Add address ranges to a virtual network.
- Delete address ranges from a virtual network.
- Resizing of address space is supported across tenants.
I’ve covered you with a step-by-step guide on confidently resizing the address space of peered Azure virtual networks. In this blog post, I created two virtual networks in Azure: one in Sydney, Australia East region and another in Singapore, South East Asia region.
Let’s establish a global peering connection between the virtual networks. First, click on the Sydney VNET and select “Peerings” in the Settings. Then click “+ Add” and provide a name for the peering. Choose the remote virtual network and give a name for the remote virtual network peering.
I will change the Sydney region VNET address space from 10.0.0.0/24 to 10.0.0.0/22 and save.
The connection between the virtual networks has been altered and needs to be synchronized.
To synchronize operations, access the peering settings of the virtual network and click on the desired peering name.
Choose the resync option to restore regular peering connectivity and save your selection.
Note: This feature does not support updating virtual networks peered with a classic virtual network or a managed virtual network like Azure VWAN hub.
Santhosh has over 15 years of experience in the IT organization. Working as a Cloud Infrastructure Architect and has a wide range of expertise in Microsoft technologies, with a specialization in public & private cloud services for enterprise customers. My varied background includes work in cloud computing, virtualization, storage, networks, automation and DevOps.
