Azure Subnet - Your subnet is not contained within the same address space for this virtual network

Question

I Virtual Network has the following subnet 10.0.0.0/24 and I want to add another but each time I try I get: "Your subnet is not contained within the same address space for this virtual network"

How do I add another subnet?

Answer 1

You can add a Subnet in your Virtual Network but first need to create Address Space.

This can be done here - Virtual Network>Address Space>Add Additional Address Range>Save

Now you can use this new address space to create a Subnet.

Virtual Network>Subnet>Name, your new Address Range will be displayed here>OK

Answer 2

There's a flaw in the page also. If the Add subnet blade is currently open, close/cancel it. Next, click in the IP Address Space field that you filled in, then click out of the field. Then create your subnet. Seems there is a problem with the field not saving before the Add Subnet blade opens.

Answer 3

this means your address space is exhausted or you are trying to add the wrong address space. go to the virtual network properties and check what address space it is using. if it is exhausted - you can add more address spaces to it (if you dont have peerings\vpn gateways)