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?

Aciculate

can you share what subnet you are trying to add? You should be able to add 10.0.0.1 FIRST IP - 10.0.0.254 LAST IP. Don't kill yourself. Use cidr.xyz – Homerus

thats not exactly true. azure reserves first 3 and last 1 ip address from each subnet – Manifestation

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

Impertinence

You are the best! – Prostatectomy

Answer 2

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)

Manifestation

Answer 3

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.

Epilogue

Answer 4

Go to your Virtual Network, then Subnets, and Add one that is not "Default". Use 10.0.1.0/24 for example, which gives you 251 IPs. You do not need to create a new address space.

In the dropdown for selecting a Virtual Network and Subnet, the non-Default one will be available.

Naturalist