DEMO: Expanding a CIDR Block Subnet to Have More IP Addresses
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1h 1m

This course has been designed to teach you how to manage networking and compute resources on Google Cloud Platform. The content in this course will help prepare you for the Associate Cloud Engineer exam.

The topics covered within this course include:

  • Adding subnets to a VPC
  • Expanding existing subnets
  • Reserving static addresses via the console and Cloud Shell
  • Managing, configuring, and connecting to VM instances
  • Adding GPUs and installing CUDA libraries
  • Creating and deploying from snapshots and images
  • Working with instance groups

Learning Objectives

  • Learn how to manage networking and compute resources on Google Cloud Platform
  • Prepare for the Google Associate Cloud Engineer Exam

Intended Audience

  • Those who are preparing for the Associate Cloud Engineer exam
  • Those looking to learn more about managing GCP networking and compute features


To get the most from this course, you should have some exposure to GCP resources, such as VCPs, VM Instances, Cloud Console, and Cloud Shell. However, this is not essential.



Welcome back. In the last lesson, we talked about some of the details surrounding the expansion of a CIDR block subnet. In this demonstration, I'm going to show you how to do it.

On the screen here, you can see that I'm logged in to my Google Cloud Platform Console. To expand my CIDR block subnet, I need to browse over here to the VPC Networks page. Now, from this page, I can see all of my networks and subnets in my project. Now, these are going to be shown, as you can see here, in a hierarchical view. My existing subnets are shown as entries within each of the networks.

What I need to do here is click the name of the network that contains the subnet that I want to expand. And we're going to expand my new subnet here. So we'll click test-network. From this VPC Network Details page I can then click the name of the subnet in the Subnets tab so I can view the subnet's details page.

Now, clicking Edit here allows me to enter a broader CIDR block in the IP address range field. I'll change this subnet from a /16 to a /15. What this does is make more addresses available for devices within this subnet. So, with my new CIDR block defined here, I just have to click Save to make it active.

Now, just a heads up, the expansion of the primary IP range of a subnet can actually take several minutes to complete. However, traffic within the subnet will continue to flow, unaffected, during the expansion. This process creates zero downtime.

Join me in the next lesson where we'll talk about reserving IP addresses.

About the Author
Learning Paths

Tom is a 25+ year veteran of the IT industry, having worked in environments as large as 40k seats and as small as 50 seats. Throughout the course of a long an interesting career, he has built an in-depth skillset that spans numerous IT disciplines. Tom has designed and architected small, large, and global IT solutions.

In addition to the Cloud Platform and Infrastructure MCSE certification, Tom also carries several other Microsoft certifications. His ability to see things from a strategic perspective allows Tom to architect solutions that closely align with business needs.

In his spare time, Tom enjoys camping, fishing, and playing poker.