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Even if you’ve studied what border gateway protocol (BGP) is and how to take advantage of the best pathways for multiple clouds, most network engineers find the process more complex than they expected. Figuring out the best networking through services like Amazon Web Services (AWS), Microsoft Azure and Google Cloud Platform (GCP) takes a lot of behind-the-scenes work.
Every cloud has its own networking design, routing and connectivity models. Even minor differences in BGP behavior can cause performance and availability issues when connecting the clouds. One misconfigured autonomous system number (ASN) or route leak will cause latency spikes, creating a multi-cloud headache instead of a simplified multi-cloud solution.
The Trouble With Multi-Cloud Connectivity
Connecting to AWS, Azure and GCP would mean using a VPN or directly connecting to a cloud. BGP would be enabled. However, it’s more like three different power grids that share electricity. Each grid has a slightly different system and names things using unique conventions.
AWS uses virtual private clouds (VPC), Azure uses a virtual network, and GCP uses its variant of VPCs with Google Cloud Router, allowing BGP routes. Each platform has its own network, subnet, gateway, routing and network address translation implementation. Some clouds, such as those in AWS, have regional network routing, while others, like GCP, have global network routing.
A 2025 Lancaster University study found that BGP routing varies globally due to geolocation models and the way network operators use selective announcements. You cannot assume behavior is the same everywhere.
With so many routes to manage each new cloud, you’ll also need new route tables, ASNs and BGP sessions. Without a consistent or hierarchical naming convention, there is an increased risk of route collision, loops and redirecting traffic to the wrong destination.
Remember that when you move data from one provider to another, you incur potential costs and latency via unintended hops across clouds. Operational overload in updates, checking for problems and debugging failures across three dashboards plus three different support teams can get overwhelming.
Multi-cloud networking is complex because you are trying to integrate three different systems, each with its own design philosophy, into a cohesive network. This creates a fragile situation. However, it can be easily managed with careful design and routing policies.
How to Architect a Multi-Cloud Network
A few steps will ensure you build your system on a solid architecture.
1. Define the Connectivity Model
You can use the hub-and-spoke model or the mesh model. In the hub-and-spoke model or decentralized design, each cloud provider or on-premises data center, which signifies the spokes, is connected to a central gateway or hub. This design offers several advantages, including ease of understanding and troubleshooting, scalability as the number of managed networks increases and robust network isolation.
These characteristics apply to most multi-cloud networking designs. If your workloads generate a lot of traffic between clouds, the hub can become a bottleneck, and you should consider redundancy and scaling requirements.
In a mesh model, you link every cloud and data center with low latency and high resilience. However, this model is far more complex. Each added link has routing and configuration overhead and potential operational impact. There are special use cases where cloud interaction is very close to real time, such as in a global financial network.
A hub-and-spoke architecture is easier to use and scale for most organizations, with mesh added only where latency is most problematic. However, the network becomes increasingly complex with each additional connection.
2. Choose an Interconnect Provider
Establishing connectivity to multiple cloud providers is not as simple as creating VPN tunnels between your environment and each cloud. You also need an intermediary location for all your networks, which a link provider could fulfill.
A software-defined cloud link or colocation provider is a neutral exchange point for private, high-speed and low-latency connectivity between your enterprise network and multiple clouds. Rather than establishing and managing three physical circuits to connect to the three biggest clouds — AWS, Azure and GCP — you connect once to a platform that pairs with each.
In some industries, cloud computing is growing rapidly. For example, 66% of manufacturing enterprises across 17 countries use some type of cloud structure and have sought systems that will scale as they grow.
Data center partners give you a physical presence in neutral facilities and allow you to plug into AWS Direct Connect, Azure ExpressRoute and Google Cloud Link directly. Traffic is exchanged inside each other’s private backbone networks rather than over the public internet, creating lower latency. At the same time, information is transported on separate circuits for stronger security.
3. Configure BGP and Routing Policies
Now that the networks are connected, controlling how routes are learned is necessary. It often makes sense to use different ASNs per cloud. Some organizations use the same global ASN across the clouds. Clarifying and documenting paths is crucial.
Employ route filtering to control prefixes and receive updates in each cloud. This avoids route leaking, route looping and displaying internal networks. Consistently name peers, tables and gateways for easier identification in different environments. Experts recommend route origin validation and prefix filtering as crucial components for securing BGP.
Build redundancy into your BGP sessions. Most teams either use active/active pairs to provide highly available failover or active/passive pairs to reduce costs. Traffic engineering can be performed using BGP attributes, such as local preference and AS-path prepending, and route counts and BGP session health can be collected for this purpose. A dropped advertisement can unexpectedly break cross-cloud connectivity.
4. Test and Validate
Just because the sessions show as established does not mean the configuration is correct. Testing for application is vital. Ensure that there is end-to-end reachability between all clouds and on-premises systems, that routes are propagating correctly and that each peer receives only the prefixes it should receive.
The next type of test you should do is failover testing. Drop one of the BGP sessions by bringing down a link or pushing traffic to a particular location. Then, check whether redundancy kicks in. Individual failover tests reveal your blind spots.
Document everything. Always have your ASNs, peer IPs, route filters, timers and policies. A clear picture of your network will help new engineers get up and running faster, making recovering from issues easier.
5. Maintain and Adjust
Think of your live network like a living organism. Workloads move around a cloud environment in flux. Regularly auditing the route tables and BGP sessions helps network managers identify problems before they cause damage.
Review your filtering rules upon adding subnets or moving workloads. Monitor your bandwidth usage to ensure the links are still fast enough. Review and test your backup and disaster recovery paths quarterly to ensure traffic follows the expected path. Keep the vendor documentation up to date, as routing behavior changes frequently.
Strong teams take documentation, testing and monitoring seriously, viewing them as engineering tasks and planned maintenance.
Chaos Containment to Avoid the Multi-Cloud Mess
BGP management across AWS, Azure and GCP will always be complex, but it does not have to be a jumble of confusing paths. A suitable connectivity strategy, a trusted link provider and a strong routing hierarchy allow the use of different clouds to become a cohesive whole. Planning and regular auditing allow your multi-cloud network to behave like a single machine rather than three competing ecosystems.
