Demystifying Azure VNet-to-VNet Peering: A Simple Guide

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2 min read

Demystifying Azure VNet-to-VNet Peering: A Simple Guide

Introduction: In the vast landscape of Azure networking, Virtual Networks (VNets) play a pivotal role in connecting and isolating resources. One powerful feature that Azure offers is VNet-to-VNet peering, allowing seamless communication between VNets. Let's dive into the world of VNet peering in simple terms.


What is VNet-to-VNet Peering? Azure VNet-to-VNet peering is like connecting two virtual networks together, creating a secure and private link. This enables resources in different VNets to communicate, as if they are on the same network, without going through the public internet.


How to Set Up VNet Peering:

  1. Navigate to the Azure portal.

  2. Go to the 'Virtual networks' section.

  3. Select the VNet you want to peer.

  4. Choose 'Peerings' and add a new peering connection.

  5. Repeat the process for the other VNet.


Do's and Don'ts:

Do's:

  1. Plan Your Address Space: Ensure there's no overlapping address space between the connected VNets.

  2. Check Azure Region Compatibility: VNets must be in the same Azure region or in regions connected via ExpressRoute or VPN Gateway.

  3. Configure Network Security Groups (NSGs): Fine-tune NSGs to control traffic between peered VNets.

Don'ts:

  1. Overlap Address Spaces: Avoid using the same IP address range in both VNets.

  2. Peering Across Regions Without Gateway: Without ExpressRoute or VPN Gateway, peering across regions is a no-go.


Important Points to Note:

  1. Performance Impact: Peering is done through Azure backbone, ensuring low-latency communication.

  2. Transitive Peering: If VNet A is peered with B and B is peered with C, A can communicate with C indirectly.

  3. Resource Communication: Resources in peered VNets can communicate using private IP addresses.


When to Use VNet Peering:

  1. Multi-Tier Applications: Ideal for multi-tier applications spread across different VNets.

  2. Hub and Spoke Architecture: Perfect for creating a hub-and-spoke model, centralizing services in one VNet (hub) and connecting other VNets (spokes).

  3. Geographical Redundancy: Enhances disaster recovery scenarios by connecting VNets in different Azure regions.


Conclusion: Azure VNet-to-VNet peering is a robust feature simplifying network connectivity between Azure resources. By understanding the do's and don'ts, along with use cases, you can leverage this technology to build flexible and scalable architectures within the Azure cloud.


Disclaimer: This blog provides a simplified overview. Always refer to Azure documentation for detailed configurations and updates.

https://learn.microsoft.com/en-us/azure/virtual-network/virtual-network-peering-overview