How do you implement network isolation for multi-cloud deployments?

In network isolation, multi-cloud deployment prevents cross-cloud attacks and data exposure by controlling network traffic between different cloud environments, ensuring compliance and isolating critical businesses. Its importance lies in meeting the data privacy requirements of high-security industries such as finance and healthcare, and supporting secure collaboration across platforms like AWS, Azure, and GCP.

Core components include Virtual Private Cloud (VPC), private connections (e.g., AWS Direct Connect/Azure ExpressRoute), encrypted tunnels (IPsec/TLS), and network policy tools (e.g., Calico/Security Groups). By dividing logical network boundaries and combining with the zero-trust model, it achieves isolation at the microservice or database instance level, reduces the fault diffusion surface, and meets standards such as GDPR.

Implementation steps: 1. Divide network domains: Create independent VPCs or VNets in each cloud and segment them by application layer; 2. Establish secure connections: Use dedicated VPNs or cloud direct connections to ensure encrypted communication and avoid public network exposure; 3. Configure policies: Set firewall rules and SDN policies to control cross-domain traffic and implement continuous monitoring. This solution reduces the risk of data leakage and improves the overall resilience, security, and controllability of cross-cloud applications.