Subnetwork expansion adds even more flexibility to your Google Cloud Platform private networks



The promise of public cloud networking is about securely meeting the demand of customers even if your needs grow more quickly than expected.

To address this challenge, today we’re introducing expandable subnetworks, a new capability that lets you quickly and efficiently expand your subnetwork IP space without disrupting running services. This enables more efficient control of your network as the compute resources and number of users on your network grow.

In addition, you can extend your Google Cloud Platform subnetwork both geographically (diagram 2 below: growing across new regions) and within an existing region (diagram 3 below). You don’t have to make irreversible IP allocation planning decisions up front.

Our existing subnetwork capabilities already allow you to extend your private space across additional regions as needed. Now, with the introduction of expandable subnetworks, you can also extend the IP ranges of pre-configured subnetworks without any impact to existing instances and workloads. That means you can accommodate additional compute capacity within your existing subnet simply by expanding your IP ranges — without the need to reconfigure or recreate your existing workloads.

To illustrate the power of subnetworks, let’s consider three situations.

  • Specify deployment regions while enjoying a global private space

    Consider an initial deployment that requires your application to run only in the US West and US Central regions. It's possible to decide based on your requirements to host your applications exclusively in those specific regions.

    Further, you can now customize the IP ranges of networks with regional subnetworks. The IP range configuration model provides maximum flexibility by allowing several subnetworks within the network to be configured with IP ranges that don’t need to be aggregated at the network level. Each subnetworks is configured regionally, covering between two and four different availability zones, depending on the region, allowing workload mobility across zones keeping a persistent IP address.
    (click to enlarge)
  • Grow your Virtual Private Cloud with subnetworks in new regions 

    Assume that customer demand now requires you to grow in the US East and Europe West regions. You can easily add new subnetworks in those regions within the same network by configuring a new IP range that's non-contiguous with IP ranges in other regions.
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  • Expand the size of your subnetworks in existing regions non-disruptively

    You can now resize your subnetworks without disruption as demand for your application grows. No need to delete existing instances or services configured in that subnetwork. Simply grow in each region as your business grows without additional planning.

    In the example below, the IP ranges in US West and US Central are experiencing additional growth and require additional compute capacity. In order to accommodate that additional capacity, the IP range can be expanded from a subnetwork with a prefix mask of /20 to a prefix max of /16 without having to reconfigure existing workloads. Machines using the same subnet in a region can be configured in any of the availability zones in that region. In this case, two machines in 10.132/16 in us-central1 are configured in two availability zones (A and B). This network flexibility is the byproduct of Google’s SDN
    (click to enlarge)
Google Cloud Virtual Network allows you to have complete control over your virtual networking environment, including selection of your own IP address range, creation of subnets and expansion of those subnets across regions and within region.

GCP provides you with the elasticity to expand your network in the regions where your applications grow. These new features are available now and you can start using them today. And if you’re not already running on GCP, be sure to sign up for a free trial.