Expand Azure Virtual Network

Q. I created an Azure Virtual Network with a small address space and now need to expand it, is this possible?

A. Unfortunately you cannot modify the address space for a Virtual Network. While individual Virtual Subnets within a Virtual Network can be modified if no resources are within the Virtual Subnet, the address space of the Virtual Network itself cannot be modified post-creation. Therefore, when creating a Virtual Network in Azure always err on the side of being too large. There is really no downside to this approach. If you are in a position of needing to extend the address space of a Virtual Network there are two options:

Note that both options are very invasive and not desirable.