Connect resources in a virtual network to on premise resources through an IPSec tunnel present in another VNet

Question

We already have an IPSec tunnel connected to on-prem resources.
We want to create resources in another virtual network and provide them with access to the resources on-prem through the IPSec tunnel.
How can we go about achieving this?

Answer 1

Hi @Shirisha Sudhakar

You will need hub-and-spoke network architecture, and enable gateway transit, gateway transit allows spoke virtual networks to share the VPN gateway in the hub, instead of deploying VPN gateways in every spoke virtual network

https://learn.microsoft.com/en-us/azure/architecture/reference-architectures/hybrid-networking/hub-spoke?tabs=cli

to set up VNet Peering between the gateway transit see documentation bellow:

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

https://learn.microsoft.com/en-us/azure/vpn-gateway/vpn-gateway-peering-gateway-transit

Get in touch if you need more help with this issue.

--please don't forget to "[Accept the answer]" if the reply is helpful--

Answer 2

@Shirisha Sudhakar Rao

Thank you for reaching out.

If I understand it correctly you have Azure VPN already set-up and connected to your on-prem resources and now you wish to add another virtual network in Azure and grant it access to your on-prem resources.

Based on my understanding above. Yes, this is possible. To enable this connectivity, you will need to peer the new virtual network with the virtual network containing your VPN Gateway. While setting up this peering you need to enable Gateway Transit property. Gateway transit is a peering property that lets one virtual network use the VPN gateway in the peered virtual network for cross-premises connectivity. Routes to the gateway-connected virtual networks or on-premises networks will propagate to the routing tables for the peered virtual networks using gateway transit. You can follow this documentation for enabling this connectivity.

Additional resources:

https://learn.microsoft.com/en-us/azure/virtual-network/virtual-network-manage-peering?tabs=peering-portal#create-a-peering

https://learn.microsoft.com/en-us/azure/virtual-network/virtual-network-manage-peering?tabs=peering-portal#requirements-and-constraints

Hope this helps! Please let us know if you have any additional questions. Thank you!