A network administrator needs to expand the primary IPv4 address range of an existing custom-mode VPC subnet in Google Cloud from to without creating IP conflicts or interrupting active virtual machines. In what chronological order should the administrator execute the following steps to ensure a successful and non-disruptive range expansion?
- 1Audit existing on-premises and peered VPC network address spaces to confirm that the contiguous IP block () has no overlapping ranges.
- 2Confirm that the target subnet mask () is broader than the existing mask () and that the expanded boundary fully encloses the current block.
- 3Run the gcloud compute networks subnets expand-ip-range command specifying the subnet name, region, and new prefix length of 23.
- 4Inspect the subnet properties in the Google Cloud Console or via gcloud to confirm the updated primary IPv4 range reflects .
Answer
The correct operational sequence begins with auditing adjacent networks for IP overlaps (), confirming that the requested CIDR expansion fully encloses the existing subnet range with a smaller netmask prefix, running the gcloud compute networks subnets expand-ip-range command, and finally verifying the updated subnet CIDR configuration.
Expanding a primary IPv4 range in GCP requires verifying non-overlapping address space across interconnected networks before making changes, confirming that the new prefix encloses the old range (e.g., expanding from to ), executing the gcloud compute networks subnets expand-ip-range command, and verifying the change upon completion.
Step-by-Step Solution
Key Concept
Subnet IP range expansion procedures and constraints in GCP Custom Mode VPCs