Interconnected Kitchen: Link Azure And AWS With A VPN

Most of the busiensses nowadays are not stick with one cloud provider because they are running workloads across two or more platforms at same time. This setup is known as multicloud and it is more like running a kitchen with ingredients from two different suppliers, each one good at something the other is not. This is how AWS is often selected for its wide range of the services and maturity. Azure is chosen due to its strong integration with Microssoft tools and enterprise systems.

Well most of the companies use both of them, which is not accidentally, but because each platform has some unique qualities. Here the tricky part is about getting these two environments connected with each other in a secure way. As data is transferred among AWS and Azure there will be need of private, encrypted path between the two clouds. This will enable resources from both sides to reach with teh help of Site-to-Site VPN becomes genuinely useful.

In this guide we have discusses why this connection matters a lot and what components are needed and how to set it step by ste. If you are looking to learn the cloud networking, through an AWS Course, this is the kind of practical setup you will likely run into in real projects.

Understanding Site-to-Site VPNs

A Site-to-Site VPN is basically a way to connect two networks over the internet, but keep whatever they are sending to each other private. Instead of just sending the data out in open, it puts that data inside a tunnel which is encrypted. So even if someone try to catch that data in between, all they get is some scrambled information which makes no sense to them.

This whole thing works because of a protocol called IPSec. It handle two jobs at once, first it encrypt the data, and second it also check that the data is actually coming from the right place and not from someone pretending to be it.

Now why this matter so much when we talk about Azure and AWS together? These two are completely different networks, and by default they don't trust each other at all, there is no natural connection between them. A Site-to-Site VPN solve this problem. It create a private channel between the two, so the traffic can move back and forth safely, without it ever going through the open internet in plain, unprotected form.

Here is a simplified view of how the connection flows:

Azure Resources

 ↓

Virtual Network Gateway

 ↓

Encrypted IPSec Tunnel

 ↓

Virtual Private Gateway

 ↓

AWS Resources

Each side has its own gateway component, and the tunnel between them is what keeps the traffic encrypted end to end.

Why Connect AWS and Azure?

There are several practical reasons businesses connect these two platforms rather than picking just one. Networking concepts like these are often paired with AI-focused training too, and professionals working toward an AWS Certified AI Practitioner Course frequently need this kind of multi-cloud foundation, since AI workloads are increasingly spread across more than one provider.  Disaster recovery is common problem where the company keeps a backup on a second cloud for outage of primary one.  

On the other hand, some of the businesses divide their application across both the platforms by running the certain workloads on AWS and others on Azure. It is mainly dependent on which service may suit each of the task in a better way. Here the business continuity will play an important role ass depending on a single provider can be risky when something goes wrong at the end. Also certain industries have regulatory requirements that push companies toward specific providers for specific types of data, which naturally leads to a multi-cloud setup.

But the thing that matters most is connecting AWS and Azure, giving businesses more flexibility without being locked into a single ecosystem. These are the real-world skills you gain in a Cloud Computing Course. 

Components Required for the Setup

Before configuring anything, it helps to know exactly what pieces are involved on each side. This is also a good point to build a mental map of how AWS and Microsoft Azure Course networking terms relate to each other, something that often comes up in an AWS Course Online focused on hybrid cloud architecture.

Azure Components

Virtual Network (VNet): the private network space where Azure resources live.

Gateway Subnet: a dedicated subnet reserved for gateway traffic.

Virtual Network Gateway: the Azure-side endpoint for the VPN tunnel.

Local Network Gateway: represents the AWS side from Azure's point of view.

AWS Components

Virtual Private Cloud (VPC): the private network space where AWS resources live.

Customer Gateway: represents the Azure side from AWS's point of view.

Virtual Private Gateway: the AWS-side endpoint for the VPN tunnel.

Site-to-Site VPN Connection: the actual configuration that ties everything together.

Table 1: Components Used in the Setup

Network Planning Before Configuration

Before touching either console, it is worth planning your IP address ranges properly. This step gets skipped often, and it usually causes problems later.

Table 2: Example Network Design

The two address ranges should never overlap with each other. If they do, then routing between the two networks becomes impossible, because system will not know which network a particular IP address actually belongs to. So planning your IP ranges before you even start creating resources, it make the rest of setup go a lot smoother and you don't end up redesigning your whole network somewhere in the middle.

Configure the Azure Environment

Step 1: Create the Virtual Network

The first step that you need to implement is creating a Virtual Network in Azure, along with the application that subnets you are planning to use for your actual workloads.

Step 2: Create the Gateway Subnet

A Gateway Subnet is needed specifically so that Virtual Network Gateway can work properly. You won’t be able to skip this or integrate the same with the regular subnet, Azure will keep it reserved only for teh gateway traffic.

Step 3: Deploy the Virtual Network Gateway

While deploying the gateway, go with the VPN Gateway type, not the ExpressRoute one. Set it to route-based configuration since this is what supports the dynamic routing that a Site-to-Site connection needs. Azure will give this gateway a public IP address automatically. The deployment usually takes around 30 to 45 minutes, so you need to be a little patient here.

Once the deployment is done, note down that public IP address of the gateway somewhere safe. You will need this exact IP later when setting up the AWS side. This step is actually a common exercise in an AWS Course in Noida, since it makes learners work across two different cloud consoles at the same time instead of staying stuck in just one platform.

Configure the AWS Environment

Step 1: Create the Customer Gateway

In the AWS you can build a Customer Gateway and put the same in the Public IP of the Azure Virtual Network Gateway that you noted earlier. Well it basically ask AWS where the Azure tunnel is located.

Step 2: Create the Virtual Private Gateway

Next, create a Virtual Private Gateway and attach it with your VPC. This becomes the AWS side endpoint for the VPN connection.

Step 3: Create the Site-to-Site VPN Connection

Now you configure the actual VPN connection, connecting the Customer Gateway and Virtual Private Gateway together. Set the routing type as static, and enter the Azure network address space so AWS knows exactly which traffic needs to go through the tunnel.

This kind of complete setup is also a common practical task given in an AWS Course in Pune, where learners have to finish both AWS and Azure sides of the tunnel on their own, without step by step help. Once this connection gets created, AWS gives you a configuration file with all the details you need to finish the setup. Download this file, since it has the shared key and tunnel details required on the Azure side.

Good to know that AWS creates two separate tunnels automatically for this connection, Tunnel 1 and Tunnel 2. This is done on purpose for redundancy, so the connection doesn't completely drop even if one tunnel stops working.

Finalize the Connection in Azure

Create the Local Network Gateway

You may need to create a Local Network Gatewat back in Azure. Here you need to add the public IP of one of the AWS tunnels, along with the AWS VPC's address space. This allows the Azure to know how to send the traffic towards AWS.

Create the VPN Connection

Then create the actual Site-to-Site connection in Azure. This needs the shared key that AWS generated, plus references to both the Virtual Network Gateway and Local Network Gateway you made earlier.

Once boh of the slides got set perfectly, this can take few minutes before the connection status shows as connected on both platforms. Such delay could be normal, so give it some time beforeassuming something has gone wrong. 

Configure Routing and Test Connectivity

When you set the VPN tunnel it doesn’t mean that traffic will automatically begin to follow correctly. Because Routing table still need to set up property on both of the slides. It means checking the route table is essential to make sure that traffic going to Azure is ddirected towards the Virtual Private Gateway. In Azure, route propagation needs to be turned on so gateway's routes get picked up correctly by rest of the network.

Once routing and security rules are set, test the connection with simple methods first, a ping between resources on each side is usually the fastest check. After that you can try SSH or RDP depending on your operating system, and finally test any real applications that depend on communication across the two clouds.

High Availability with Dual Tunnels

Like mentioned before, AWS sets up two IPSec tunnels by default for every Site-to-Site VPN connection. This isn't just some small technical detail, it's an intentional design choice made for redundancy. If one tunnel goes down, maybe due to maintenance on AWS end or some unexpected failure, traffic can keep flowing through the second tunnel without a complete outage happening.

For any production setup, it's worth properly configuring both tunnels instead of depending on just one and treating the second as optional. Skipping this basically defeats the whole point of having redundancy built in.

Common Issues and Troubleshooting Tips

Most people who have taken Amazon Web Services Certification Course may have faced one of these problems mentioned here:

Incorrect pre-shared key: 

even a small typo here stops the tunnel from getting established.

Missing route entries: tunnel can show as up, but traffic still won't reach its destination.

Tunnel status verification: 

always check both tunnel statuses in AWS Management Console and connection status in Azure before assuming there's some deeper problem.

Going through these one by one, starting from the simplest checks, usually solves most connection issues pretty fast. People preparing for an AWS Cloud Practitioner Certification Course often find that fixing basic networking problems like these builds confidence before they move on to more advanced, AI-specific service setups.

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Conclusion

Connecting AWS and Azure through a Site-to-Site VPN gives businesses a secure and practical way to run their workloads across both platforms, without exposing any data on the open internet. IPSec encryption keeps the traffic protected throughout the tunnel, and proper routing on both sides makes sure that traffic actually reaches where it's supposed to go. The dual tunnels that AWS sets up by default add an extra layer of reliability, which matters a lot once you're actually running production workloads.