To restrict access to Google Cloud Platform (GCP) resources to a specified IP range, the client can use VPC Service Controls. VPC Service Controls provide additional security for data by allowing the creation of security perimeters around GCP resources to help mitigate data exfiltration risks.

VPC Service Controls: This service allows the creation of secure perimeters to define and enforce security policies for GCP resources, restricting access to specific IP ranges.

Trust-List Implementation: By using VPC Service Controls, the client can configure access policies that only allow access from trusted IP ranges, ensuring that only users within the specified network can access the resources.

Granular Access Control: VPC Service Controls can be used in conjunction with Identity and Access Management (IAM) to provide fine-grained access controls based on IP addresses and other conditions.

References

Google Cloud VPC Service Controls Overview

VPC Service Controls enable clients to define a security perimeter around Google Cloud Platform resources to control communication to and from those resources. By using VPC Service Controls, the client can restrict access to GCP resources to a specified IP range.

Create a Service Perimeter: The client can create a service perimeter that includes the GCP resources they want to protect.

Define Access Levels: Within the service perimeter, the client can define access levels based on attributes such as IP address ranges.

Enforce Access Policies: Access policies are enforced, which restrict access to the resources within the service perimeter to only those requests that come from the specified IP range.

Grant Access to Auditors: The client can grant access to company auditors by including their IP addresses in the allowed range.

References:VPC Service Controls provide a way to secure sensitive data and enforce a perimeter around GCP resources. It is designed to prevent data exfiltration and manage access to services within the perimeter based on defined criteria, such as source IP address12. This makes it the appropriate service for the client’s requirement to restrict access to a specified IP range.