Errors in Virtual Networks - Address space overlaps

Brass Contributor



We have warnings like this from a few days in all the virtual networks:

Address space '' overlaps with address space '' of virtual network 'vnet-eu-we-glb-sandbox'. Virtual networks with overlapping address space cannot be peered. If you intend to peer these virtual networks, change address space ''.


But we don't have any network with this address space. And it appears in all the virtual networks, but we don't do changes in the infrastructure.


It's a big problem for us, as we created two new virtual networks, the warning appears and we can't create peering between them.


How can we solve it?


5 Replies


The same here. This warning message now appears in all of our virtual networks.

Do u have access to all the subscriptions I too had a similar issue and found someone has created a similar vnet on the subscription where I dont have visibility . sometimes that is one of the best practices to offload all the network vnet creation to network admin
Maybe you can open a support call with Microsoft or check with your global admin who has better visiblity
best response confirmed by mgfeal (Brass Contributor)
It was a problem with the Azure Portal for a lot of clients. Now it's solved
also check if there is any network physical network with the address. We had similar issues with the VNET IP and Another physical network, the issue will lead to round trips if you make calls from onprem


I did encounter that network didn't show in Azure portal nor CLI, but indeed Microsoft checked it existed from the backend, would suggest to raise a ticket for Microsoft to check