Azure-Virtual-Network-Peering Operator Guide

Azure Virtual Network Peering enables seamless connectivity between two or more Azure Virtual Networks. Azure Virtual Network Peering is designed to enable network migration, multi-region connectivity, and multi-subscription configurations.

Use Cases

Network Migration

Peering can facilitate a smooth network migration by allowing services to be moved from the old virtual network to the new virtual network over time while maintaining connectivity.

Multi-Region

Azure supports Global Virtual Network Peering, which enables the peering of virtual networks across Azure regions.

Multi-Subscription

Azure Virtual Network Peering supports connectivity across different Azure subscriptions and even across Azure Active Directory tenants.

Design

This bundle is tailored for two scenarios:

1. Peering two Virtual Networks, both of which are provisioned by Massdriver and in the same Azure subscription.
2. Peering two Virtual Networks, only one of which is provisioned and managed by Massdriver.

Both Virtual Networks in the Same Subscription Provisioned by Massdriver

In this case, both Virtual Networks are managed by Massdriver and are in the same Azure subscription. Users should connect both Virtual Networks to the bundle (one to accepter and the other to requester). It doesn’t matter which network is the accepter or requester; they are functionally equivalent. The bundle will handle all the necessary configurations, including establishing the peering connection and syncing the connection.

Virtual Networks in Separate Subscriptions, or Only One Managed by Massdriver

In this case, the bundle will use the requester connection only. You’ll need to specify additional field for “Remote Virtual Network ID” to initiate the peering correctly. No additional manual steps will be necessary in the Azure portal to complete the peering process.

Steps to Manually Accept Peering Connection

1. Log into the Azure portal for the accepter subscription.
2. Navigate to the Virtual Network Overview page.
3. Choose JSON View in the top right corner.
4. Copy the id value near the top (without quotes). For example: /subscriptions/123456-1234-1234-1234-12345678/resourceGroups/foo-bar/providers/Microsoft.Network/virtualNetworks/foo-var-vnet
5. Paste the id into the Remote Virtual Network ID field in the bundle and deploy
6. Navigate to the Virtual Network Peerings page.
7. Click on the peering connection.
8. Click Resync and Save.

FAQ

Can my address spaces overlap?

No, they cannot overlap. By default, the Azure Virtual Network bundle uses our Auto-CIDR feature to provision your VNet and using an address space that does not overlap with any other address space for any other VNet in the same subscription. If you are using a custom CIDR, you will need to ensure that the address spaces do not overlap.

If you are peering your VNet to a VNet that is not managed by Massdriver, you’ll need to ensure that the address space for each VNet does not overlap.

I’m trying to peer VNets across subscriptions, but I’m getting an error.

If you are peering VNets across subscriptions, you’ll need to ensure that Microsoft Entra B2B collaboration is configured.