S2S VPN with overlapping addresses in azure & azure firewall

Question

Hello Team,

We are connecting multiple on prem sites to azure with overlapping subnets.

1. Can you suggest how to handle overlapping of address space?
2. I also have azure FW in azure and connecting through P2S vpn. Is it possible to use user based policies in azure Firewall?

Answer 1

@Manuji

Thank you for reaching out. Based on your questions above.

Can you suggest how to handle overlapping of address space?

Azure VPN Gateway can connect overlapping, on-premises sites with overlapping IP address spaces through network address translation (NAT) capability. You can follow this documentation here to configure NAT with the Azure VPN Gateway

I also have azure FW in azure and connecting through P2S vpn. Is it possible to use user based policies in azure Firewall?

Yes, you can use Azure Firewall and Firewall Policy to control network access in a hybrid network using rules that define allowed and denied network traffic. You can create Network rules and Application Rules based on your requirements to allow and deny traffic. You will have to User Defined Routes to direct the traffic via Azure Firewall. YOu can refer to this tutorial for more information regarding this set-up https://learn.microsoft.com/en-us/azure/firewall/tutorial-hybrid-portal-policy

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

---

​​Please "Accept the answer" if the information helped you. This will help us and others in the community as well.