About Regional VNets and Affinity Groups for Virtual Network
Updated: June 10, 2014
Previously, when creating a virtual network (VNet) you were required to associate the VNet with an affinity group, which was in turn, associated with a Region. This requirement has changed. Now VNets are associated directly with a Region (Location) in the Management Portal. This allows you more freedom when creating your VNets. You can still associate your cloud services with affinity groups when appropriate, but you are not required to do so.
The Region represents where the Virtual Network overlay will be. Anything you deploy to the virtual network will be physically located in the Region. If you want to further designate that you want your resources in close proximity physically to each other within the same region, you can specify an affinity group for those particular resources. That would mean that not only are those resources in the same physical location, they are very close to each other in the datacenter.
The Region (Location) is the physical location on a larger scale than an affinity group. When you create your VNet, you’re specifying where you want the resources that you deploy to the VNet to be physically located.
Affinity groups are a way you can group your cloud services by proximity to each other in the Azure datacenter in order to achieve optimal performance. When you create an affinity group, it lets Azure know to keep all of the services that belong to your affinity group as physically close to each other as possible. For example, if you want to keep the services running your data and your code together, you would specify the same affinity group for those cloud services. They would then run on hardware that is located close together in the datacenter. This can reduce latency and increase performance, while potentially lowering costs.
Affinity groups are defined at the subscription level and the name of each affinity group must be unique within the subscription. Each affinity group you create is tied to a Region (which is the Location). Specify the same region when creating your affinity group and your virtual network.
You create a Regional VNet exactly the same way you’d create any virtual network. The Management Portal now only contains the option for Location (Regional) VNets, so if you follow the basic steps, you’ll be creating a Regional VNet. You can also upload a network configuration file. See About Virtual Network Settings in the Management Portal for more information.
No. You can’t convert a VNet that was created previously. However, all existing VNets that are bound to affinity groups will be migrated to Regional VNets in the near future. If you want a Regional VNet right now, you can create a new VNet in the Management Portal or by importing a network configuration file (netcfg).
Yes. See Configure a VNet to VNet Connection for more information.
Azure supports Regional VNets in the regions listed here, except Brazil South, which is currently in Preview.