Multicloud Networking for AWS, Azure & GCP: Architecture, Challenges, Best Practices

What Is Multicloud Networking?

Multicloud networking is the practice of designing and operating connectivity, routing, segmentation, security, and visibility across two or more public cloud providers, most commonly AWS, Microsoft Azure, and Google Cloud. While each cloud offers mature networking services, enterprises often struggle to apply consistent networking and security controls across clouds. This guide explains the core challenges and outlines architectures and best practices for building a secure, high-performance multicloud network.

Why Enterprises Adopt Multicloud

Enterprises adopt multicloud to align infrastructure decisions with application needs and business priorities. Common drivers include:

• Avoiding dependency on a single provider and improving resilience

• Using best-of-breed services across clouds (data, AI/ML, analytics)

• Meeting compliance, data residency, or sovereignty requirements

• Supporting M&A and integrating environments faster

Multicloud Networking Challenges

While multicloud leverage makes a good public cloud strategy, enabling a multicloud architecture that includes two or more cloud providers is a challenge on many fronts. From an enterprise point of view, all the considerations and requirements for access, networking, and security that applied to one cloud provider must apply to all clouds you use.

While each provider’s underlying infrastructure services are built to address networking, segmentation, isolation, load balancing, security, and access, and each provider delivers a sophisticated management and orchestration interface to configure these IaaS services, there is no common command and control for multicloud networking.

While each public cloud provider brings a rich set of common infrastructure services, they are all unique in their nomenclature, function, configuration, APIs, control and visibility. In addition, these services need to deploy, orchestrate, configure, and provide visibility using each cloud providers orchestration and management console. Each cloud provider provides automation and scripting tools that only address their services.

AWS vs Azure vs GCP Networking Services

AWS, Azure, and Google Cloud deliver similar building blocks for networking, security, and connectivity—but they differ in naming, APIs, configuration, and operational workflows. The comparison below highlights core services enterprises typically use when building multicloud networks.

*For more information on varying terms and definitions across cloud providers, see our Multicloud Rosetta Stone.

Learning and leveraging multiple providers and their IaaS services is a big challenge for many enterprise cloud architects and cloud network engineers.

In this new era of cloud computing, multicloud network abstraction is essential.

Illustrating a Challenge of Multicloud Networking by Using vRouters

Each public cloud vendor—including Amazon Web Services (AWS), Microsoft Azure, and Google Cloud (formerly Google Cloud Platform or GCP)—has its own structure and workflow. For obvious reasons, they don’t make it easy to connect with a competitor’s cloud infrastructure. As a result, an enterprise’s Cloud or DevOps teams are left to establish connections manually: a complex, tedious, and time-consuming process.

Here are the typical steps for connecting two public clouds:

1. Log into each cloud provider’s IaaS console – AWS EC2 Console, Azure Portal/Resource Manager, and Google Cloud.

2. Configure the AWS VPCs, Azure VNETs, or Google VPCs with non-overlapping subnets.

3. Configure relevant networking services for each cloud provider (for example, VPC CIDR, subnets, route table, DNS, NAT, FW, or Internet Access).

4. Install cloud provider-specific instances based virtual router (for example, Cisco CSR1000V or Palo Alto VM-FW) in each cloud provider’s VPC or VNET.

5. Using the CLI of each virtual router, configure the virtual router and its services to function as a router for that VPC or VNET.

6. Configure IPSec VPN between the two virtual routers. IPSec VPN configuration could be a multi-step procedure based on virtual router type and typically requires deep network and security knowledge.

How Aviatrix Enables Multicloud Networking

Aviatrix empowers enterprises to embrace their multicloud strategies while empowering their cloud and DevOps teams. Instead of forcing the cloud professionals to handle the complexity of networking between and within multiple cloud vendors’ footprints, enterprise cloud teams can:

• Review and manage all the enterprise’s public cloud instances and resources using a single, abstracted view.

• Gain the freedom to choose the right public cloud deployment option for each application and workload, without getting bogged down in time-consuming intricacies of how to connect them all.

• Add and change connections between and within various public cloud resources automatically and at real cloud speeds, rather than spending a couple of weeks manually building connections—or waiting even longer for the IT networking experts to step in and handle the networking chores.

• Enable the use cases that best serve the enterprise’s business goals, whether that means migrating workloads from one public cloud to another or mirroring the environment in one public cloud to another public cloud for backup and disaster recovery (DR).

Secure Multicloud Networking with Aviatrix

The Aviatrix Cloud Network Security Platform is the industry’s leading multicloud networking software that abstracts the networking layers across AWS, Azure, and Google and allows multiple clouds to be networked from a single unified management plane. Achieve robust security, reliable connectivity, high performance, and essential agility for your entire multicloud network.

Curious about multicloud networking best practices?

• See our multicloud networking guides for network engineers and DevOps teams.

• Review a Checklist for Building a Secure Multicloud Network.

• Learn how Better improved multicloud security and compliance with Aviatrix.

FAQs About Multicloud Networking

What is multicloud networking?

Multicloud networking is the practice of building and operating connectivity, routing, segmentation, security, and visibility across two or more public cloud providers—most commonly AWS, Microsoft Azure, and Google Cloud. While each cloud has strong native networking services, multicloud networking focuses on making those services work together in a consistent way so applications can communicate reliably and securely across clouds.

How do you connect AWS, Azure, and GCP securely?

A secure approach typically includes:

• Private connectivity where possible (Direct Connect, ExpressRoute, Interconnect) for predictable performance and reduced exposure.

• Encrypted tunnels for traffic between clouds (IPsec VPN, or application-layer encryption with TLS where appropriate).

• Consistent segmentation and policy enforcement so only intended paths are allowed.

• Centralized identity and access control (least privilege, RBAC) for administration.

• Unified logging and monitoring to detect misconfigurations and threats across clouds.

In practice, most enterprises use a combination of private interconnect + encryption + centralized policy + continuous visibility.

VPN vs Direct Connect / ExpressRoute / Interconnect—what should I use?

It depends on performance, cost, and operational requirements.

• VPN (IPsec)

  • Best for: quick setup, lower cost, smaller bandwidth needs, dev/test, backup paths

  • Tradeoffs: variable throughput/latency; more sensitive to internet conditions

• Dedicated private connectivity (Direct Connect / ExpressRoute / Interconnect)

  • Best for: production workloads, high throughput, consistent latency, regulated environments

  • Tradeoffs: longer lead time, higher cost, and additional design considerations

A common pattern is:

• Use private connectivity for primary production paths

• Keep VPN as a secondary/backup path or for environments where private connectivity isn’t available

How do you prevent overlapping CIDRs across clouds?

Overlapping CIDRs are one of the most common causes of multicloud routing failures. The most reliable prevention is governance and planning:

• Define a global IP addressing plan before expanding multicloud

• Allocate non-overlapping CIDR blocks per cloud, region, and environment (prod/dev/shared services)

• Use centralized IPAM (or a controlled registry) to manage allocations and avoid collisions

• Standardize VPC/VNET creation so teams can’t “self-assign” IP ranges ad hoc

• Validate continuously—catch overlaps early during provisioning rather than during incident response

What are best practices for multicloud network segmentation?

Segmentation is how you reduce blast radius and enforce least-privilege connectivity. Practical best practices include:

• Start with a consistent model across clouds (for example):

  • Shared services (DNS, identity, security tools)

  • Application tiers (web, app, data)

  • Environment separation (prod, staging, dev)

• Enforce policy using cloud-native controls (security groups/NSGs/firewalls) but keep the intent consistent

• Use central inspection/egress control where required (especially for internet-bound traffic)

• Avoid “flat networks” and large permissive rules; prefer explicit allow lists

• Treat segmentation as code: versioned policies, change control, and drift detection

How do you get end-to-end visibility across AWS, Azure, and GCP?

End-to-end visibility requires normalizing signals from each cloud and correlating them across the path. A solid baseline includes:

• Enable and centralize:

  • Flow logs (traffic metadata)

  • Routing and connectivity state

  • Firewall/security events

  • Audit logs for configuration changes

• Standardize dashboards around:

  • Connectivity health (tunnels, peers, interconnects)

  • Latency/packet loss and path changes

  • Allowed/denied traffic by segment

• Correlate across clouds to reduce “console hopping”

• Add alerting for common failure modes:

  • Route changes, tunnel flaps, policy drift, CIDR overlaps, asymmetric routing

The goal is a single operational view that answers: what changed, what broke, where, and why—without manually stitching together three separate toolchains.