Securing Multi-Cloud Networks: From Immediate Controls to Zero Trust

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This document provides a detailed strategy to assess, secure, and future-proof multi-cloud distributed infrastructure. The focus is on addressing external threats, evaluating current and emerging network patterns, and providing actionable guidance for improving security through automation and structured guidelines.

1. Objectives of Network Assessment

Immediate Threat Mitigation

Secure external-facing components such as ingress/egress points, public-facing services, and overly permissive configurations.

Cloud-Native Product Context

  • Assess how various products are deployed across AWS, Azure, and GCP accounts.
  • Identify patterns in network requirements based on customer and product needs.
  • Incorporate these patterns into a long-term strategy to align network security with business goals.

Future-Proofing and Automation

  • Provide guidelines for automating network configurations using Infrastructure as Code (IaC).
  • Ensure alignment of network security with future growth and product deployments.

2. Phased Network Assessment and Strategy

Phase 1: Asset Discovery and Risk Prioritization (Q1)

Comprehensive Inventory

  • Public-Facing Components: Identify load balancers, DNS entries, WAF rules, NAT Gateways, Internet Gateways, Security Groups, ACLs, and API gateways across all accounts.
  • Private Connectivity: Map VPC peering, transit gateways, VPNs, Direct Connect, and private endpoints.
  • Legacy Configurations: Highlight older components with unclear ownership.

Product and Customer Mapping

  • Map deployments of products like SPACE, Voice, and CPASS across accounts.
  • Identify dependencies such as inter-region data transfer, CDN usage, and secure replication.

Initial Risk Categorization

  • High: Public endpoints with misconfigurations or no WAF.
  • Medium: Overly permissive peering or ingress rules.
  • Low: Configurations with no immediate exposure.

Phase 2: External Threat Mitigation (Q2)

North-South Traffic Hardening

  • Audit all ingress/egress traffic across load balancers, gateways, and APIs.
  • Enforce “deny-all” defaults, restrict to known IPs/ports, and require TLS.

WAF and DDoS Protection

  • Enable WAF for all critical endpoints with OWASP Top 10 protection.
  • Apply DDoS safeguards for APIs and high-traffic workloads.

DNS and Public IP Cleanup

  • Consolidate DNS records and deallocate unused public IPs.
  • Use private DNS zones where possible.

Cross-Cloud Security

  • Replace legacy public endpoints with private connectivity wherever possible.

Phase 3: Internal Traffic & East-West Security (Q3)

Network Segmentation

  • Enforce segmentation for public, private, and restricted subnets.
  • Audit VPC peerings for excessive permissions.

Data Flow Mapping

  • Visualize account-to-account and region-to-region traffic.
  • Remove unnecessary lateral movement paths.

Inter-Service Communication

  • Restrict service-specific connectivity to required ACLs and policies.

Multi-Region and Multi-Account Consistency

  • Standardize configurations and enforce templates for all regions/accounts.

Phase 4: Standardization & Automation (Q4)

IaC Guidelines

  • Use Terraform for VPC, subnet, security group, and firewall automation.
  • Automate DNS management and peering setups.
  • Integrate security validation into CI/CD pipelines.

Patterns for Future Deployments

  • High-performance inter-region transfers.
  • Secure, isolated customer environments.
  • Low-latency CDN and edge deployments.

Legacy Modernization

  • Phase out manual configs in favor of automated IaC templates.

Monitoring & Metrics

  • Track reductions in public-facing resources.
  • Measure automated network coverage and misconfiguration remediation rates.

3. Key Deliverables for the CloudSec Team

  • Network Assessment Playbook: Step-by-step audit and remediation guidance.
  • Architecture Diagrams: Visual maps of traffic flows and security gaps.
  • IaC Templates: Pre-configured multi-cloud modules for networking.
  • Future Guidelines: Best practices for secure scaling.

4. Long-Term Vision

Enhanced Automation

All network configurations transition to IaC with CI/CD enforcement.

Zero Trust Adoption

Gradual implementation of zero trust for inter-service and inter-account communications.

Product-Centric Approach

Align network security directly with product deployments, ensuring focus on:

  • Public endpoint protection.
  • Secure multi-region data flows.
  • Customer-specific configurations.

Bottom line: By addressing immediate threats, building product-aware policies, and automating for scale, this strategy provides guidelines for securing multi-cloud distributed systems that remain compliant, resilient, and ready for the future.

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