Multi-Cloud Networking: How to Connect AWS, Azure and GCP Securely
Connecting workloads across AWS, Azure, and GCP is technically straightforward in the sense that connectivity options genuinely exist for all three. It's considerably harder in practice, because each platform's networking model works differently under the hood, and a design pattern that works cleanly within one platform doesn't translate directly to the others without real, deliberate adaptation.…
Linking workloads between AWS, Azure, and GCP may sound technically simple, but it's far more intricate in reality. Each cloud platform maintains unique networking models, making direct application of one platform's design patterns to another challenging. The most significant risk in multi-cloud networking doesn't originate from any single platform's connectivity issues—it stems from inconsistencies in security and routing applications across platforms.
Each provider's native networking model operates distinctly, leading to gaps at the intersections between them that escape detection by single-platform security assessments.
AWS Virtual Private Clouds (VPCs), Azure Virtual Networks, and GCP Virtual Private Clouds are not interchangeable despite their similar nomenclature. Their underlying structural differences in peering, routing, and access control can result in subtly incorrect assumptions when applying an AWS-centric design to Azure or GCP. For instance, GCP's VPCs are globally interconnected by default, unlike AWS and Azure, where VPCs are regionally scoped.
Consequently, achieving multi-region connectivity in AWS or Azure necessitates explicit peering or transit gateway configurations, a task that's inherently more complex than in GCP.
Three primary approaches exist for direct connectivity between cloud providers: VPN connections, dedicated interconnects, and third-party network-as-a-service platforms. Each method presents distinct advantages and trade-offs. VPNs are accessible and cost-effective but may suffer from variable performance. Dedicated interconnects offer superior performance at a higher cost and greater setup complexity.
Third-party platforms streamline connectivity across all three environments, simplifying management but potentially relinquishing some direct control.
AWS security groups, Azure Network Security Groups, and GCP firewall rules serve similar purposes but diverge in syntax, default behaviors, and rule evaluation logic. A policy correctly implemented in AWS doesn't seamlessly translate to Azure or GCP due to differences in implementation. Specific gaps include the inherent stateful behavior of AWS security groups, which automatically permits return traffic for allowed connections, unlike some equivalent constructs on other platforms that necessitate explicit bidirectional rules.
This discrepancy can lead to security vulnerabilities if engineers assume stateful behavior universally.
DNS resolution across a multi-cloud setup can also become inconsistent, contingent on the DNS services provided by each cloud provider. Without a deliberate, unified DNS strategy—whether through a single provider's DNS extended across environments or a genuinely platform-agnostic DNS solution—organizations risk experiencing unpredictable failures in DNS resolution.
This inconsistency often goes unnoticed until an incident spans multiple platforms, revealing the absence of centralized visibility. Building centralized network monitoring and logging that aggregates data from AWS, Azure, and GCP is essential for managing multi-cloud networking securely. Without such unified visibility, security teams face difficulties in diagnosing and resolving issues that manifest at the seams between platforms, as siloed visibility precludes a comprehensive view of incidents spanning multiple cloud environments.
Written by urgent.news from Dev.to's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
