Any issue if two vnet address space overlaping

Question

Any issue if two vnet address space overlaping

Rocky Mondal 106

Hi,

We have two vnets with same address space 10.0.0.0/16 overlapping address space.

message is showing vnet peering is not possible in overlapping address space vnet.

Now we are planning to implement Azure firewall. My question is this any issue we will face to configure in azure firewall in overlapping address space vnets?

KapilAnanth-MSFT 49,616 Reputation points Microsoft Employee Moderator

2023-05-18T11:38:55.3566667+00:00

@Rocky Mondal

Just checking in to see if the below answer helped. If this answers your query, please don’t forget to click "Accept the answer" and Up-Vote for the same, which might be beneficial to other community members reading this thread. And, if you have any further query do let us know.

Thanks,

Kapil
KapilAnanth-MSFT 49,616 Reputation points Microsoft Employee Moderator

2023-05-19T04:08:07.5566667+00:00

@Rocky Mondal

Reaching out to check if there are any questions on this.

Please let us know if we can be of any further assistance here.

Thanks,

Kapil

Please Accept an answer if correct. Original posters help the community find answers faster by identifying the correct answer.

Here is how
KapilAnanth-MSFT 49,616 Reputation points Microsoft Employee Moderator

2023-05-22T06:25:22.7033333+00:00

@Rocky Mondal

Request you to Accept the answer" and Close this thread.

Do let us know should there be any follow-up questions.

Cheers,

Kapil

2 answers

Your answer

KapilAnanth-MSFT 49,616 Reputation points Microsoft Employee Moderator

2023-05-18T11:38:55.3566667+00:00

@Rocky Mondal

Just checking in to see if the below answer helped. If this answers your query, please don’t forget to click "Accept the answer" and Up-Vote for the same, which might be beneficial to other community members reading this thread. And, if you have any further query do let us know.

Thanks,

Kapil
KapilAnanth-MSFT 49,616 Reputation points Microsoft Employee Moderator

2023-05-19T04:08:07.5566667+00:00

@Rocky Mondal

Reaching out to check if there are any questions on this.

Please let us know if we can be of any further assistance here.

Thanks,

Kapil

Please Accept an answer if correct. Original posters help the community find answers faster by identifying the correct answer.

Here is how
KapilAnanth-MSFT 49,616 Reputation points Microsoft Employee Moderator

2023-05-22T06:25:22.7033333+00:00

@Rocky Mondal

Request you to Accept the answer" and Close this thread.

Do let us know should there be any follow-up questions.

Cheers,

Kapil

Answer 1

msrini-MSFT 9,291 Microsoft Employee

Hi,

I would suggest you to have a setup done with a non-overlapping address space if you want those 2 VNETs to communicate with each other. This was you can scale your design as needed and it will reduce the complexity.

on the side note, even when you have introduce the Azure Firewall in a hub vnet, you will not be able to peer other 2 spokes which has the same address space.

Regards,

Karthik Srinivas

Answer 2

KapilAnanth-MSFT 49,616 Microsoft Employee Moderator

@Rocky Mondal

Welcome to the Microsoft Q&A Platform. Thank you for reaching out & I hope you are doing well.

I understand that you would like to know if there are any issues with having overlapping Azure VNets.

Overlapping Azure VNets are not an issue as long as you are not going to connect them, either via Peering or Vnet-to-Vnet VPN Connection
When you say you are planning to implement an Azure Firewall, this generally means that you will be deploying this into one specific VNet.
Now, since only one VNet is in the picture, there should not be any issue.

Kindly let us know if this helps or you need further assistance on this issue.

Thanks,

Kapil

Please don’t forget to close the thread by clicking "Accept the answer" wherever the information provided helps you, as this can be beneficial to other community members.

Rocky Mondal 106 Reputation points

2023-05-17T13:09:10.44+00:00

Hi Kapil,

Thank you for reply.

Understood Overlapping Azure VNets are not going to connect either via Peering or Vnet-to-Vnet VPN Connection.

We want to deploy one Azure firewall in multiple Vnets, Can we do that ?

Or we can only deploy one Azure firewall in one Vnet? please suggest. Thanks
KapilAnanth-MSFT 49,616 Reputation points Microsoft Employee Moderator

2023-05-17T14:10:40.4066667+00:00
@Rocky Mondal

We want to deploy one Azure firewall in multiple Vnets, Can we do that ?

No

An Azure Firewall can be deployed into a single VNet only.

If you want multiple VNets to leverage a single Firewall,

Then you should link these VNets via Peering to the VNet in which the Firewall is deployed.

This will become a Hub Spoke Architecture

This requires you to have VNets that do not have an overlapping address range.

Refer:

Hub-spoke network topology in Azure

Secure your hub virtual network using Azure Firewall Manager

Hope this helps.

Thanks,

Kapil

Please Accept an answer if correct. Original posters help the community find answers faster by identifying the correct answer.

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Any issue if two vnet address space overlaping

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